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AA-JP76A-TH

December 1987

534 pages

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45MB

Document:	VAXmate Technical Reference Manual Volume 1 198702
Order Number:	AA-JP76A-TH
Revision:
Pages:	534
Original Filename:	http://bitsavers.org/pdf/dec/vaxmate/AA-JP76A-TH_VAXmate_Technical_Reference_Manual_Volume_1_198702.pdf

OCR Text

IBX1nate"
Technical
Reference Manual
Volume 1

The nl~):·erj;.tt 1n th~s rj_,·;.ctJrnern. 1<.; for ittf~Hs.n;,ttit•naJ pn.qi-cise~ :i'.nd n~ ~ubit~\_.r to ch~tngt·
.,_~,/ithon;:: node~::: jt :'<!}1(.1uhi n(H. be ~_:1)n;.;u:ucd ~ts a C\Hnrnit:nt~P_r by Dig.ital Equipr:nc.ni:
(.'.urp1.)ratkH1. Digitai. Equiprn.t::nt C1__,q)<_,r;:!.l~~-Hi as.":urn.c~; .rid n:~-"'·f:.'-'Ofb·ihUity for ;1n_y-e1n)r;;_
tha.r rtL-t)' ;q:-pcat in t~ti.,,.. dz,(:un<{~'.1!
~ )i_gin: Eq111 pint~nl C(itp<'Jf<lt i(1f1 a..-;st.; <ncs '10 n.:;sfh.H1~-_ i)).i i.ity t(}i: rht' 1.1 "e (If r r·f ~;rbi i ity t)f lr;.;

f-()fT\\·;u-c on cqu.ip1~1(·n1~h~u.15 n1·-1t ~qppHed ~,y Digit;,;t.
,'\JS-ll'i."l'.~

\1~, .\\-'1.Ni 'I(.!-\\.1'3

;i:n.d l\-1',;. !\j t: !'a rt' 'i'Cld\':tn~~rk....; of j\:f i~:ro~n-.1 t ~- ·,,.irp{.1t:H:_~'i_ ::·1.

Tnp\-i<:v,- i.'~ .o) n·~-1rJcn~.;iri---; of Jntcrc~\df.'Jflal Busines ...: 1_:;,y-p ...•radoo.

Yl(Jt(_1.ro!a •s a rcµis'lCr(~d 1r-at.1c111ark nf 1\!:_:;~((tGl:'.1.

j,·:i\-.

tBM PC J\"t i.<-; :: u-.1;Ji:-r=1~-tr~~ of f.ntr-rn:lr/,--:-nal Ihi:,h1·:::s~ \'l~1i1. :hnics C<,rpor;_n.~o:'.'L

~n~aamn

Pr•_.Jfcs~?.on~il

DH.

1-C:.d f". LH }'S

DLl>~y~,H~n! -1:}

Thin\\/irc

RSX
.:.1Ec;;t-s rr:t\·r ::~t·:
Ul:(:t

().'VJNJB!i'...

Contents

Preface .

xxxm

VOLUME 1
Ch1:1ptcr l VAX mate \Vorkstaiion Overview.
Bas•~ System .
Optional Components

1-1
hl

Chaptt·r 2 VAXmate Microproc(~ssor.
Overvi.ew.

Heal Address Mode
Prnlected Virtual Address .Mode.
Coprocessor.
Additional Smirces nf l nforrnatlon .

,., ,,

Memorv Map

lnputiOutput Addn·i>s Map
!nterrupt Vector Map
and Structure.
Bus
E;<p;msion Box Tcchnka! Spr•cifkut.ions

2·l 0
;•.JO

Expansion Bnx Op•.:rnting Ranges

Chapter ;} Interrupt Controllers
Overview ..
A.dditiornii Soun·p of Information.
H1,mt·\·Vdte ( ;onJrnl

Conlents

iii

Lnit!.oI:zaUc-n t>~n1u11find. \li/.;_-~rd ;3
1(~.\V'1- ;_rvi~~:stt:r)

J-1 :cl
;~. ;,
J-:.1;

l-; ,:,

:H7

'°'.>

~--.n

/-.

,,)-£..;;:

£r;t.::~trlrY·, (\;ritt1_Jih;r

(\'.::! n r-1 ~~ c_"! <~

·) 'k-~

4-7
ll1M<e and Cun-Pnt Address Hegistcr .

4-7

!:lase and Current \'Vord Register

4·H

Cornmand R.eg'i.5Ler ..
Write Slnp;le Mosk Bit.

•H1

\Vrit.c AH Tvfosk Bits
Mode Reg-iste!"

Request
Status Register
Rei;ister .
Progn1.mming E.xa1npl(!

4-1 l

4-11
4-1 1)
4·U
4·14
4·.! 4

Const;mt VHlue<;

4-1.5

D<1ta Structures

4-17

lnltializ\11g the DM.A Cont;n;ller

4-18

a D.MA Channel .
Preparing- a Channel for Data Tr::msfer .
DL$abling a J)ll/IA Chonnel . . .

4 Hi
4 20

4·22

Chapter 5 Real-Time CloPk nnd CMOS RAM.
(h'crview.

Adtlitional Srituce of Information
B:1ttery· Rai:·kup Conskkrati.ons.
ilie He<1Ffin1e Clod;;
Real·Time Chwk Heg-isters

ti<i

Heg'!S\t)r A.

fi-·i

Hep;i"ltt)r B.
Hegister C
Hegister D

{)~()

HeBl·Time Clock D<•t<i H:cg-i.sters .

Alarms ..
Uptfate Cycle ,
lnterrnpts
UpdMe·Ended Interrupt
Alarm Interrupt .
Progrnmmi.ng f<;xami1lc
C•mstant Values
Data Structures
Heading- the Registers and HAM.
VVriting the fteg;isters and H/\.M
Calculating the Cherksum .
Cniwerting Bimiry-Coded Data.

Heading the D<Jt.e

5·8
b-9

5-10

5·14.
f)-14

5·15
5-lt)

5-J 8

6·20
5.:;,[
5·22
f12:{

f:i·2-i

Contents

fkading the Time
Displ<1ying the Date
Disp!Hylng t.lw Time .
flisp!aying the Diskette Drive Type.
Displaying the !-ford Disk Type .
the Clock Interrupts . ,
Interpreting the R;\M Conr.ent;;
l niti;ilizing the Hcal·Ti.rnP Clock .
Restoring the Interrupt Vectors ,
ftc;ll-Time Clor:k Example

h·~28

5·-29
f>-:3 ()
6-'.:\4
;).;! ,:,

;.-:Jn

Chaptt•r 6 Three·Chunnel Counie1• and SpN\ker
(h-en:ie;>· .
Additional Source ot .!n!ornwtlon
Bln('k Diag;rnm ,

c·mmtcr
M.ode Definitions

Mode ii Hnt.crrupt on T(•rn1inal Connt)
Initializing J\fodc I)
Ji.fode 0 Cyde.
Mede 1 O-l;irdw1Jrn Hetriggernble One-Shot!

Mode 2 mate· Generator/
Mode 2
.l\lodc 2 Cyde. , ..
J\·fode ::I {Sqtwre Wave Mudei
1.niti:i!bng lVfodc :~ , , , .
,"vfode :~
]';Jode 4 \Software Triggerf'd StrobeL
Mode 4 .
iVIude 5 O·fanlwan: Triggernu Strobe)
Initializing Mode f:i

Mode fl Cycki

U-7
6-7
6-7

6-8

f>ystem Register .
Control \Vord Ht'gistcr
Counter- Latch Cnmm;md ((;(mtrol V\ford Heg:ist.erl
Read-Buck Comrmrnd iControl Won! Register)
Statu5 Hesp(Jnsc 1Hc1:1dh<1ck Commandi

Contents

G-n
(Ht

G-12
U· ;-1
f) .. 14

Progn1mming Exampk•
Con:-;tant Vnlues .
Writin?; n ('.ounter

G-1G
G-1 G

6·!8

M<iking a Bt-ll Suund
Countm· and Speaker ExamplH.

6-18

6-:w

Chapter 7 Video (;ontrolfo1· . .

7·1
7-1

fotrndnetim1 . .
lndut<try-Stundard Text <lfld Oraphics Fe~it.ures .
Enhancements to lndustry-Standnrd Fc<iturcs
lndnstry·Strrndard F12atures Not AvaH;ible
r~xt.ra Fpatures
Block Diagram . . . . . .
i\ddit;[ona! Sour<:es of In fornw ti on
Video !\'lodes
Tt'Xt 1\:lndes .
('.bar;ici:er Buffer Fonnat .
Cb.Mader Position to Memory Loc;Jtinn Mapping
Progr;immable Cursor
Prognu:nmahlo Cha ruder Uenerntor ffont HAM) .
Graphics !\lode
Tvlappin.g: the Display to Address
Video Look·Up Table
Viden Syst.c.m Registers
Special Purpose Register
CHTC Hegisters
l.ndex R.egb:ter.
Data lfogister
Heg:ister RO
Register H !
Hegister R2
R:'i
fkg-istei H 4
Register Rf\
Hegister mi
Regii<ler Hi
Ht'[';isrcr Hx

7-G
7-13
7.7
7-8
7-!)
7-10
710
7·18
7-22
·7-2:1
"/·:!.6
7-2:)
7-~i)

7 ·28
7 28
7-29
7-2~1

7-30
7.:10
7<~ J
7-:~ J

7-82
7~:1

Hcgister IUO
Hegbter HI l

7-:H

Hegister HJ 2

7-.34

7-:H

7<'13

Contents

vii

Registrn R14

7-:rn

7-:'\t)

7-;Jfj
!'!'

(;;...,.

' 4, _:r ~

Color Select R.egist.H
(~ontrcd

7 ::18
7-:19
7 ::rn

Control
Monit<:•r lnh;rt<!Ct'

l\.1f1nitor

Example
Chaph~r 8 Ke,ybourd·Int.erfm.:e Controller nnd Keyboard

lntrodur:tirm . .
Cpntroiier
Physieai Interfoce to tbe CPU
fnterfoce to the Keyboard
Lngiclll l.nterfacc .
Control Function:, .
Keyhonrd-Intcrfau~ f:omr<1Jler
J\eybmird·Intnrface C:omrnller
Dat.a Register.

8--fj

('.ornrrw.nd

8-fi

Stutu~ Register.

.';-!)

Comrrwnd 1lug1shff

Read ComnMnd Byte .
VVrit.e Curnrnand Byte
Self-Tes!, .
lntedace T·~st
Disable l\•cyb••ard
Enah]p KPybnard
Hmid Port !..
H.ead Port l.
He11d Port 2,
\Vrit•! Port 2

8-!J
81H
!HO

8 1~)
B· 1.'.~~:
8-12
8-12
8-12

8 rn
8- J.:!

H.c~1d .._-re~t Inputs

VI/rite Starns Hegist.or.
Pulse Output I'mi:
Eeyb•iHrd-.lnt.erfan" Contwller Error Haru:i!iug.

i)-1 ~j

S· 13
8·14

U<.:250 1-\eybmml
Snin Codr•s .
LK2fi0
Comm0nd Codes
!n\·alld {.'on1rnands
!.Zeybn;ird ID .
Ent~)r DIGITAL Extended Senn Code Mode.
Exit. DIGITAL Extended Sc<m C1;de l\lodP

Set Keyboard LE.D . .
He;;;ct
LED.
Set
Volnme
Lnabl.e I\lttnrepeaL
Disabk Autorepeat
Mode Lock.
h.eybu;H'd \fode Unlock.
Hcserved
LEDs On;OH.
Edm.

8·22
tH.'3
~~2<3

8 23

8-23
8 ~>.i
8-24

8·24

8-2G

8<.W

Hu-;erv(:d

8-26

Set AHton°pcat Delay and Hate
Eoahle
Dis<.1ble Key Sconning and Restore to Defaults

8-27

Ht·store To Defau.lts.
Heserv1·ed
Hcsc11d .

82H

Heset ..
Lh'.?.50 l\Pyboard Hesponses
H uffcr overrun .
Self.test surrr.ss .
ECHCL
Release Pretix
Adrnowledgr; f,'\Cl'\!.
Se!.f·Test FHihJP.;.
Hesend
LK250 I\eybonrd l':rror Handling

8-W
8-29

8-:iO
8-:30

8-:w
8-:!0
8-:~.I

8-:} l
8-'.H
8·:~1

8<:11

I.US. and Foreign ''"'"'""'"n·1"

8-:~ l

E;.:.mnple

l<-4 fl

Chapter H Serial CmnmunicntionA.

Contents

Add!tionai Sources of lnfornw.tlon
Heceive Buffor HegisterlTru.nsmitter Hoidlng Hegister.
Enable
lntcrrnpt Identitie<ition Hegi::.tet.
Line Control Hegistei·
:'vl.odcm C;mtnJl Tkgister
Li:;opl)at-k
Line Stutus HPgistP!.
Modem Status
[1i1.:rJs(H' t,;Jtchcs,

'\lodem r: . mrrol
Special Purpqs._, Ilcgistcr

9.7
9-9
U·l.0

!Hl
~H3

H-15
H-! i

H ll:\

r~rnnrrn1nicntion~:: Con.nector

9~1~3

Printer Conrwctor

n-:.w

~iorlern c:onnec.:.nr Si~~na.ls,

9-21
~!-2~

ti-:n

Chapter- JO 1Vfouse Information.

10-l

l ntrodud.ion .
(;on1rnu nic;) t ion ltecg 1ir{!n1ent~~

W-1

1\driitional Source uf In-for-rnation,

10~2

Mou'ie Comm.ands
Prornµt J\foch-; Incremental Stn,;ani !\·lode.
HequesL !1/!ou"i: Position
lnvo«.c Sdf-Tc<;t .
Vem:lor Reserved Function
I,,:lou% He1)orts

10-2

P·osi ti tin J{t~port ,.,
Pos;H:i/1n R.eport - B_vtt: '.!.

Position Report ;~.
Self-1\:st Repmt. Sdf-Test H.epnrt - Byte 2
SeH-Test Hepon · Byte :.cl
Seli-Tc·st
4
Snial. Interface
Tran~mit. Holding ltegbt1.'r and Hcceive Buffer
Stat.us

10·3
tO-:~

HH
10-4
10-G
10~5

tf).fi

l 0-fl
l U· 7

lP-'t
J0-8
HH'.i

Cmnmanrl Register

HHi
] 0- l ()
10-11
i0-12

Programming Ii~xampk

10-14

Mode;
Mode

l.0-'.l
Uhl

Contents

Chapter 11 Oi.sketb• Drive Controller
Introduction . .
Diskette Drive Controller Registers .
Control Register . . .
Main St.ams Regi!<ter
Daw Hegister,
Data Transfer Ra1e Heglster .
Change Register . .
Diskette Drive Controller lntenwl Registern .
Internal .fteg-ister · Command. . . .
Internal Hf'gister - Head.ii] nit Select
Interned Register - St11tus Register 0
Internal Register · Status Register !
lnternai Register· Status Ileg·ister .2
lni,enm! Register - Status Regist.er :1
Internal Heg·.ister · SR.TIHUT
Internal Register· HLT/ND

Internal Register · C.
lnterrnl! BJ~p;ister · H.
Internal llegist.er · R.
lntern;;l H.egister · N

!nternril Register E;(lT
internal flegister · OPI..
lntcrnal Hegister · DTL
[ntcrnal Hegister - SC .
Internal Hegister · D ..
Internal Register· STP .
lntenwl Begister · PCN,
lntermil Registers· NCN
Diskette Drive Controller Programming
Command State
Execution State .
Result State ..
Command and Result Register Sets.
Progra.rnrning Exarnple . . . . . .

JH
l1·1

1 l-6

l 1. -H
U·7
11·7

l .l -10
1112
I i - Us
I1 ·14
1J.1[,

Il· l. (}
I l·!f;
11-15
l l-Hl
.11-1.6
lHfJ
11-16
1 l .1 Ii
1.1- l. 7
ii· l i
11-1-;'
l 1.' l 7

Ul8
l 1 20
J 1-20

J 1-20
l l.-27

Chapter 12 Hard Disl{ Drive ControUt•r .
lntrodw:tion . . .

Contents

F1ard IJisk \Mt-.;~troilcr
1)1;·t.a Hoo.e•1'"'··~
\.Vrite

12-;J
J.2~4

12-7

! ~;.R
U-H
t'.J-1!)

I 2-1 J
12- ,;)
\Vdte Scoctnr (•-~tnrnand.
Fot a1.Jt l'r~1ck ('orn1nd1:.id ,

12 1 b

lt~i.ai Vt~rify (:tHrJ.rna:i1d

.l2-Vl
_! ~f-? l

Cornn?:-q1d.

j 2-27

Chapter ) :~ Nel:work .ffon:!ware I ni.erface

i ;-{~ .1
j ;1,, 1

lnt.roductjun to tlH_=: l,,\NC;r~
.:\d.dhLn1al Sr_;utce of Inf0rn1a.tion.
Tt1e f>v~x 1'ra_n;-weivpr- lntfl:.rfnre

The St~tied. Interface
T'he l.it:H~t-d Area J\Ti::_~f\'\"1Jrk (~untroHer .

the L/1.NCE;
l!1.itiaJizaUun Block
ltc::::ei··.:(; (~nd l\·ansnlit
[J.:·ttri. _n-,Jj·fers

f>nntrot And Status
Con lxol '\nd S t.11tus
(\Jntrni .A.nd Stat.u?:;
x II

Cont en i.!->

D3
l ;{ . .;

Rings

j '.:l--1

t 3··1

C\mtrnl 1\od Stnni'> Ikgister a .
NICSH
!.nitiaJi·zat:ion Block.
»·lo<lc Field
A<ldress Fidd
Address P'ilter Field

13-l ;;

1:3-17
13-18
Ul-UJ

18-22
i:5-23
3 2iS
!:'.-27

t':!·2P
flcsrr~pbll.· .l

\H.MDJ 1

i:j--;Ji)

:ya·"''"n·e Desuipt11r ~ iH.l\fl)2i .
"""·,''""'" Df'Scdptor 3 IHl\:ID~il
tfransrnit I)e:;crlptor _Ring«
0 ITl\lDO!
H><.:n·•nn ,,. l ffl\1 D I.)

l =~-~}2
l:i'.~·t

i;,1.;J4
13-'.l;)

l :J-:~ T

•'frnnsn1'lt 'tvlt:.1:S$age I)esc:ript.nr rl"NlJ)::n
Nutwrwk h1tcrfa<:1' E>ctermll Interconnect

Bi1s I ntcrconnecL

Index
VOLUME:~

Chapkr 14 Syi;;tero Startup
Ch-'t~rv~t;\V.

·resr
lnh.itL\izatinn
H•o:;i :Vind<:· v,_;rsU:i Vi.rwal Prot:~d.ed Mn<lP
, .
List

IC~tcnd.c·d Seif-'rcsL.

14-'
L.i<t
1·Li
!_ 4...-f)
; ·1·!!
14-10
i4- J i

1far{1\~-a.re ~JtJrnpe:r 10·-~onfigur.:1tion,

J 4~ ! 3
l.:1.14

f'hktptcr 15 ROM BIOS .
OZ !.l · '-Jqnmr•skable Interrupt

lfi-l
l. ;<~

f-lard .Beset

O•>H: Print Scri~en
Interrupt 08H Clock Tid;:. .

'G-4
F··h

t r>~e~

Intenup1. OHH: COM2 i rvlotlem
OCH: COMl i Seri«l
lntrrrupt OEH:
Disk. _
lOH: Vid;;ii- !nput;Output
hmct.lon 00!-f: St't Vi.dt'o '.Vfoch~.

lG·G
lG 7
15-8

I:'.•·l 0

Function 0 l H.: Set Cr.H"<;q~·

Hd2

Functi•m o:n 1: Set Cursor Pnsiti.on

15-1 ;j
J ;;.j 4
l 5- "1 fa
16·-·lfJ
15-17

Fmicdon O;<;H: ftead C:.ir,:or Po,:itkir1
Funn.Jon OH!· Rtc:ad
Function Of:d.-I: St\t
F;Jnction OtH:L Sr:roH 1\c~·ive
!Jp.
functHm 07 H: Scn•ll i\ct.ive
Down
Fun·~tion 08H:

Read Chi!.racter and />,ttribute nt Cursor
t5 .rn

PosittfJD

Functirm OHH: Wrile Charm:tcr and A.ttrihute ut Cunwr
l. ".t1'" ,;.,,')'l

FuncfalJn ()A_~L ·vv:ttc C:haractc•r ut (~ur~:;;('!t PosiUnn.
FGnct~nr~ OlHI~ Set. C:ukYr Palette
t-'un{_'.ti()n O(;f-1: V\.:rit,t~ Pixe1
Funct.ion 0}).f"[: R.t~ad l?h:eJ .

r\1nct.).::H:t !;jI-l- T'T'{ V\i'ritt-} String

Funct.inn rH)J{: Enablc.'LJ.!-:;able 2f;6 ('h~;r;ifter
F'i_lnc.!:.i·~.1n i)lJi runt Jl.~\rvJ tH1d (\_llOt
Support.
Foe~ f{.1\I\.-1 Funetluns
CnJnc f\.j_ap Ftnv:ti.fJHS . , .
li;tPnupt '1 l·t Read
lnb~rrupt .J~~}·J: .Heturn l\'1r:rno1:v Size_
3H· Disk
il.'Ol .
l-L rd_ f.Ji~;k Fun.cdon'-_;
[ f ~.:.rd :Uisk Par.r1n;.eu~:J l'nb1t:'.'-l.
f!n.u::t.io~·; GOlL ln.itJ~-di.z<~'- En_·r.in:~ LJi:s.k

F\H.U.:'.".iu:·i dr)l-f_ r-'tJrc1;:1c {1 'fn:if~..k _
FuiJri i~·~n 08H. !:_ietttrn c~urrt:nt L:rive f-\,:itncn~-~tcrs,

Font-_

lfi\7

t r~<18

Function OBH: \\'rite Long,
Function OCII: Seek to Spedfk Cylinder.
Function ODH: Hard Disk Heset.
Function !OH: Test Drive Heady.
Function 1 J H: Hecalibrate Drive.
Function 14 H: F;xecute Controller l nternal Uiagnostics
Fune ion J::!H: Heturn Dri\'C Tvpr;

Function DOH Rc<ld Long 2f>6 Byte Sec;tor
Diskette Functions.
Diskette Errors ..
Diskette Parnrnctur Tables.
Function OOH: Initialize Diskette Subsystern
Function 01 H: .H.eturn Status Code of Last !10 Request
Function 02H: Head One or More Tn1ck Sectors
Function o:Hf: \\'rite One or i\lore Track Sector<: .
Fnrn:tion 04 Ii:
Oiw or More Trnck Sect.om.
Fuuct.ion Oi>H: Format a Track.
Function J!)H: Return lJrive Type.
Function lfiil: Heturn Change Line Status.
Function .1 7H: Set Drive and Media Type for F\irmat
Internipt. l·l lt AsynchnH1.ons Cmnmm1in1tions .
Function OOH" Initialiw Asynchronous Port
Function OI H: Transmit Character
Rutter Mode Erwh.led .
Function 02H: Receive Clwrncter .
Buffer '\loffo Enabled .
Function 03H: Return Asy1whro1ww; Port Stat11s,
Buffer l\fode Enabied .
Functiun l)OH r:x.tended l'vlodc
Buffeting Enabled ..
N•Jt ihcut<lon Euahled ..
Error Codes Returned .
Function DUL Send Bre-:1.k.
Function DZH: Set l\!o<lP:n Control .
Function D:HI· Retry on Timr:rJut Error
Functi.on LJ ..frj: Sr'!t: Hrmz-l HJte .
i :dl': Cassette lliput!Outp11t
Function hl.ll!; Op<.'n Devir:t:~
Function 8 l H: Close De\·h:e
f\_n1ctin11 82 J~L 'Terrnination.
Fu11dil111 8'.JH: Set a \Vuit lut>:rval,
l\mctlrm 8-1H:

1 fi ·ftl

15-52
l 5-f1'.)
.U>-54

l 5-5fi

t 5.51;
1S-ft7
l n-f)8
lf) .. :;n
15-~t;9

15-G9

15-61
15·62
1 f:\-tL'-l
15-(14

i fi~Ufi

U1-ll6
l fi-B 7
UHH:s
J.f)-()9
16-70
trJ-7:2'

1.fi--74

15-77
H>-80

15-81
15-83
< f»H4
:t 5-8f1.

H•-8H
l!'H·I';'
1 i1-88
l.fl-89
l 5-Sfl

i.c--rio
16-\)f)
1{.)~9 i

Funrt!nn Ji:J}-1: ScP.;'{('.e

Function 8Gf-f; \Ya.H. 1No ltet:u-n to lh~er;.
F\Jnir.:rinn. H7f-J: i\1ti-Ve ~J B1.uck of _l\·1-ernnr.V"
F unc:iou :)8 FL Fteturn
Size ;\_bn"/e ()nf~ 1\.·Jt:gob_yn2
FtUJ(:tiotl 8HLL
Virtu;-d l\ Iod_-t;
l\.p1etion f~OIL ffff.'»:ice I.s
F~1uct.ion 91.Fi: lntt.~trupt
Func:bn DOH: Retilrn DlOIT.c\.!,
1

Heql

f\in;_:tiGE 0'.<H:

Fc:ncfrn DOH·
Bt;ffe: ~~-~e ~·Jo:;Jt;cL~~;~on E:iud)~.cd .
.r~_1Ect-;,-Gn TJ.i JL ('.-!"'dt,~1_(-J~;r (\eint"
j b -) ,,-,

.l.G

,, ! .i. i.'

r1__:j:_cd.on rr: fJ: l)-:·ir:t;.C:• 'l\·pr: '
F\Jn~~:.~.r·n. I:i2F1: P~:r;:dleJ
L:L.:t:_~-nJ.pr

Pnrt fl(,trv

i ~:n~r:

LHJ_-~rrj;J_, Ii;:::.rd ff~;k _Bf)nt H~;:)C-to

lnterrnpt lAH: Time-of-day. . .
F'unction OOH: Read System Clock
Function OLH: Set System Clock .
Function 02H: Head Real-Time Clock .
Function 03H: Set. Real-Time Clock
Function 04H: Return RTC Date
Fti.nction OfHI: Set RTC Date
Function 06H: Set Alarm ..
Function 07H: Cancel .Alarm.
Function DOH: Return Days-Since-Read Counter .
lnt.errupt lBH: Keyboard Break .
Interrupt lCH: Timer Tick .
Interrupt lDH: Vidoo Parameters
Interrupt 1 EI-I: Diskette Parameter Tables .
Interrupt .lFH: Graphics Character Table Pointer.
Interrupt 40H: Revector of Interrupt 13H .
Interrupt 4 l Hand 46H: Hard Disk Parameter Tables
Interrupt 4AH: HTC Alarm . . ..
Interrupt 70H: Real-Time Clock ..
Interrupt 71 H: Redirect to lntermpt OAH
Interrupt 72H: Local Area Network Controller iLANCEI.
Interrupt 73H: Serial Print:er Port .
Interrupt 7 4H: Mouse Port .
Interrupt 75H: 80287 Error. .. .
Interrupt 76H: Hard Disk . . . . .
Interrupt 77H: Aviiilable IIRQ15}

15-1:35
15·136
15-136
15-137
15-138
L5-l 38
HH39
l1H39
15-140
15-140
15-14 l
15-141
15-142
15-143
15-146
15-145
15·146
15-148
15-148
U>-148
15-149
lf>-150
Hl-150
1f>·l51
Hl-15 t
15-151

Chapter 16 Programming the V AXmate Under MS-DOS
16-1
Overview.
MS-DOS Operating System Versions.
Loading MS-DOS Operating System .. ,
MS-DOS Memory Map . . . . . . . . .
MS-DOS Interrupt 21 H Digital Specific Functions
Function 30H Get MS·DOS OEM Number
Function 38H Get/Set Country Code ,

lf)·l

16-·2
!6·2
16-2

16·3
16-i:l

16·3

Loadable MS-DOS Device Drivers .

16·6
16-5
16·5

.ANSI.SYS . . . . . .
Installing ANSI.SYS . . .

Cursor Control Furn~tim1s.
l;)rase Functions . . . .
Set Graphics Rendition ..

HH5
HM

18·8
Contents

x.vii

Set l\'lodc f"u111.:tion .
R('Set l\ludc Function
Kl'yh<XJrd Kev

l(}c}()

F1.rnGtion

Mouse Driver .. , ..
Iktecting the 1\louse Driver
Video Supµort , .
Function OOOOJ. l: 1\fouse Initializatlm1
Function 000.! H: Sbow Cnrsor
Function 0002H. Hide Ctffhr>r .

16·1 l
l_\3-12
HH'.I
l.G·14
Hl·l4

1<3·1 G
IG·ll

lG-17
I\\ l 8

Function 001HH: Get Mouse Position <.md Button Statu!i
Ftmction (J!J04H: Set Mouse Cursor Pos!tiu.n .

16-19

Functlnn O(H)f)U: Get Burton Pn:ss lntonnation

1n . zo

Function OOOtH-f: Ger Button Rde:v;e Information
Fund.ion 0007H: Set .Mini.nrnm and l\faxlnmm x. Axis

Hi<? .1

~r~c,~ition

Function 001J.'Hl: Set iVlinimtun and Ma:drnum Y-Axis
Position
Function OOO!IH Define GH;phks Cursor
Function 00();\!T Define T••xt Cusor ,
function OO!lBH: Head i\fouse Motion Counters
FrnHtkin OOOC.H: Define Event. H;mdler .
Function OOfHHi~ Enable Light Pen Eumlat.inn .
Function OOOEH: Di1.ah.lc Light.-Pen Emulation .
Function OOOFl !: Set. Mouse !vlotion:Pix.el H.;;1t.io
Function OOHlH: C<mdltional Hide Cursor
Function OOUH: Set
Threshold
Function OOlCH: (kt Driver Version.
Fnnction 0024 H.: (kt ('1_iofii;;un1tion
Function il02fiH. Set Config-uration
iEG:\i Functions
F\inc1ion FOH: Hee.Hi F:GA
Function FJ H: \\'rite EGA. Heglster .
I'um:tion F2 H: Head EOA H.egister
Function F:lH: Write F:(L\ fleglstcr Group
Funcriw1 F4fl: Read E(lA Hei-;·ister Ust .
Function FfJH Write EGA Ikgisti::. List
FunrU.1.m FAli: F'.GA Fund:ions Installed
:VlS-DCiS Mrnfo1 l U Tables
fhsk Paru1neter~ ,
xviii

Cuntent."i

t (). 24
1H· '.Zfl
tfi-27
0

16<~8

HJ.:10

l6·:·W
Hl·31
HJ.~n

l.G-82

rn.aa
JO :1a

MS·DOS International Support
FONT and Gftl\FTABL.
FONTCOi\'l
OH/\FTARLCOM
Description of Fonts.
How fi'ONT.COM Affects KE;YB.COlVI and SORT.EXE.
Font File Structures .
Loadinfr f"ont Files .

Kfi;Y B . .
. .....
Keyboard Remapping
Creating Keyboard JI.lap Tnbles for International Countries
How Compose Sequenrc<> Are He1.~ognLwd .
Huw Dead Diacritical Keys Are Hecogni2.ed ..
Format and Ust• of the Cmnpose Sequence Pointer Table
Formot and U~e of the Cornpose Sequenc1~ Tranfllation
Table.
Changing to STDUS.KI~Y and F1<.1ck Again
Keybo<ird Map File Structure

li:Hl

1(l.,,J [
16-41
I(J-42

lfH2
1(1-42

10-42

16·45
lH-45
J6-4iJ

lH-47
lH-4!1
JG-49

Hi-4H
l f). 50
lH-50
IG-50
Hl-52
H>-5:::

LCOUNTHY ..

Country File Structure .
Case Conversion Tables .

l.l>-54

SORT

Hi-55

Format for Sorting· Order.
Creating- Sort Tah!es for ClwractfT Set'l

] \)-fif)
10~56

Chapter 17 ,MS· Windows on the VAXmate

J ";- J

Introduction .
Overview .
Keyboard .Driver for the LK2f>0 l\eybnard
Numeric and Edit Keypad!! .
Keyboard LEDs for the VA.Xmate LK2fi0
VAXnrnt.e Compose lfondling ,
Hcscrvt'd K!'ys Under MS-Windows . . . .
DIGITAL MS· Windows lfoyboi1rd Extensions.
DceSetLor:kSt<n:c Hock! .
OecBetKCliekVol lvoli .. , .
l)erSetAutnrep lrcpeat) .
lJecOetKbdCountry \ .l • Result.
fh~rSetCompr1seState Icompose_ nrndel
DecSctNurnlockMode hmmlnck model .

171
1.7 ·!

!7-2
17-3
1'H
17-4
l 7~C\

17 -il
17 G

! 7.7
L7-8
17-9

1710
Cont.en ts

xix

\Vindows Keyboard Processing Anomali<~H . ,

Hepeat:ing
Allowed to Change Focns,
Hlogical. Set of Keyboard Messages
lVfoppings for V/1Xmate'& LIC!iJI).

AusiToOem. OemTot\usi
ANSI to OEM THhle
OEM to ANHJ Tahir•

l.'Hl
17·1 l
l 7·12
17·1~1

17·55

17-58

!\'louse

l7-()1

Cormnu n.icatlons
L\ T Support Through thi:; \Vimluws Asynchrnnons Serial

17-f\1

l 7-62
I 7 -Wi

Coilunoni;;ations I ntertacr;
Open('omm
l.VriteComm

l 7 .{);)

Tra:isn1itCornmChar

!Hi·~

Hnnd('ornrn. .

17 .. g4

CiuseCo.mm .
Set.Com niState

1Hl4

Or)t(\mtmState

] 7-fif;

S etJ.~orn m flrca k

J7 .. 6{:1
l 7-GG
17-0i>

c lt'~ar('.onun nrea k
SctComml'..,veii (.l\.1a$k
(iett~onu11F. vt~nt i\1 ash:.
'Flu;;-,;b{;ornrn

lHW

, .

GetCoinn1Errur
Cnslrnn LAT Appliuitirm Im.erface Under Vd11d;rws
lipc11l_,,:~

7-Gfi

17-65
17·66
7-lH1
17·t3H

lpPortNamel :

Litjd.
Closd at IL<1•idl · Resu!.t
He;JdL;1t. !Latid1: H<::suit.
\Nri'.1'Lat !Latid. chi: H.e.~ult.
OctLr1tSt.;1tu2 ff,al.id1 : Rc>ult
SendLatllreak ;Lat.idr. Hn;;ult

rn:. rhe Vi\ Xmate

Stamford
Kroyboard FlnndJing
Kc:_;.rhocird
In;,.i.dc m1 MS-VVindovvs VVindow.
Ecybna.rd UCJndling Outside an J\lS·iNindm-vs Window.
A,NSJ
Inside an MS-Wini:k~w::; iVindrr,v .

l ?··67
[7-(18

17-ilS

l 7 ~J)!j
17 70
l. 7-70
17··71
i 7-7?,
l '7·74

7-7fa
l 7·7fi

Video lVfocle'i Handl0d Inside an MS-Windows \Vindow.
lnterrnpt. l lh Support
Interrupt l. 2b Support
Interrupt l fib Support
lJ nique Icon;;

17-79
I. 7-82
17-82
17-8:3
l7-8:3
I 7 -8:3

Printers
flf:C\VIN .H file Listing.

Chapter 18 VAXmate Network Soft.ware.
lntrridw:tion .
Documentation List .
Datalink
Common Definitinn F<.irmats .

.UH
18-1
18-4
18-5
1H-6

MultkMt Address Format

18·7

Software Capabilities .
D<italink Functions
Datalink Return Codes
Fnnction OOH· Initialization !dll inltl.
Function OJH: Open a Datalink Port<Jl ldll_open).
Fnnr::tion 02H: Close a Dat.allnk Port.al tdll dose).
Funr:tion o:!H: En;ible M.ult.kast Addresses
id!!_enable mull .
Function 04H: Uisahle Multicast Ad<.lresses
\dll disnhk mull.
Function ()f,ll: Transmit. tdll trnnsndtl.
Funct.ion OGH: Rcqtu.:'<t Transmit Buffer Function

UH.\
18-11

HH.:J
181.G

18-18
j 8-21

hill _reqoc'>L_ xmit) .
Fun<.ct.ion 07H: [h.,.ilbJcatc Butler ldll dea!loec1tel
Fnnction 08H.: Re<Jrl ('.lrnnuel Statm; \dH read rhanl.

18·27
18-~rn

18-W

is-:n

Function O!ff.l: Head the Portal List {dll_read_ylistl
Fum:tion<; OAH: Head the Port<1! Status
ldH.read _port.Ell/ ..
Fnnr:tion OHH: Read the Dat<ilink Counters
Id ll read count! .
Functirm OCH: .'\let.work Hoot Hcquest
idll - nchvork -- booti. . . .
. ..... .
Fun<:tion ODH: J;;nnbling a Channel Function
tddl .. enahle- chanl
Function OEH: Disabling· a Channel 1.dll._disable chant.
Funct.ifJn I l H: Head Deqwrm String· Address
ldl!_readecparm).

l8-3!)

HHO
18-4 l

Contents

xxi

Function IZH· Set Decpann Strlng /ul.drnss
idll_ st:tdecp;mni
Function IJH: External Loopback (dll._
loopbackl
l\:laintenance Orwrntion Fun.'tions.
D<Jta Link Interface to th<:' :\'f<Jl' Prrn."•JSS
function OF'H: l\fop Start and Send
!dll
rnopl. . .
Function l!lf!.: Mop Stnp klll_ mop stopi.
.Sample fhit;;Unk Session
Local Arca
LA.T S•:rvices . .
LAT Cnn-.inand Line
l)ata StnJ(.t.ures ,

.18-·!2
l 8-4~3
18·44

18 47
l.fl-47
18-47
[8-48

18<•7
18 07

Ll.\~f Functior;;s ,

Functi1n1 n:.lH: LAT Ggt Su.ms
F'u.1wtion DOH: Open Se;;sion
Function l)OH: Close L·AT Se<;sion

Function 02H Re.'ld Data

18-70

Junction OHL S•.md Duti:J

Function ODH: Get .Next LAT S<>t·vice Name
f unctiun D6H: LAT SerYice T11b!.e Huset
Function D l.H Send Break Signal
Sample Termir:;:'i Prog:rnm

Sessit'n

18 73

!8·74
l g.7;,
l g.ij.j

JH·Hii

SoftvFare

i\:IS-Netwnrk Se-ssion { 'ontrc~t _Biock ,
~l-90

Hequests.
~·\s·...-r1chronuus Notification H.out1ue

Nctwnrk Addrcssrng.
8ession Lcvd Services
:\1S-Netivork

s~~s~io.n L-ev1:.! St;rvices
MS·J\'.ePNork ::fossion Ln·el Hcwrn Codes ..
Funnion OOH and Furvtion B800H: Check for PreM'nc•:

8 -:fO
! R Bl
l >; q I
18-~!2

IB \Y\
l}.. ~H
J 8--97

r~mction :3fiH: C~rncel

Function 3:ZJ-l': lleset
Function :~:~IL St.atuH
Function fL!H_; Stntus (<±S)'-nf.hron(H_1sl
Function ~\OH: >\dd Name
Functiou BOH.: Add Name

! 8~~H:

18~ 1

J.';~l.00

1 t~·-1 tL~
l8r-lo:~

Function 3111: Delete Name (synchronousi .
Function BUI: Udete Name lnsynchrnnrms)
Function :~4H: Name Status (sym::hnmo\1si
Function B4H: Nume Status (asynchronousl
Function lOH: Call (synchronous!.
Function 90H: Call lasynchnmous) .
Function l l H: Listen tsynl'hronousl
Function 91 H: Listen tasynchnmoui>.I.
Function l2H: .H<1ngup (synchronousi
Function !)21-£: Hangup (asynchronous!.
Function l4H: Send {synchronous) .
Function 94H: Send !asynchrrmoust
Function l 7H: Send Double (synchronous).
Function 97H: Send Double (a:synchronousf .
Function l5H: Receive {synchronous!. . . .
Fum:.:tion ~l[1 II: Receive la synchronous) ..
Function 1 OR Receive Any lsynchronousj.
Function B6H: Receive Any \asynchronous}
Datagrnrn Commands
. . . . . . . . . . . .
Furwtion 20H: Send Datagram lsynchronousi.
F\mct.ion AOH: Send Datagram (asynchronous) .
funrt.inn 21H: Receive Datagram (synchnmtms)
Function A 1 i l; Receive Datagram \asynchronous)
Function 22H: Send Broadcast isynchronous) ..
Function AZH: Send Bro»(kast 1asynchronousl ,
Function ~aH·. lleceive Broadcast lsynd1ronousi
Fttnction A.8I·L Receive Brnadrast lasynchronousi
DJGITAL·Specifk Session L(~vel. Services . . .
Function OOH: DIGITAL Functirn1 Check
(dedunccheckJ . . .
Function OH!: Add a Node {decfuncaddl . ,
Funcl.ion 02H: Ddet.e T±:ntry Given tht~ Node Number

18·104
18-104
18·Hl5
l 8- lll5
18-107
18-107
.18-1 O!l
18·] 09
HHlO

HH.10
18-111
18-U l
18-1.12
18-.112

18-113
18-1 la
18· l 14
18·114

18-U5

HHl6
18··1 U>
IIH!7
l8· l 17

18 ) 18
18-I 18
l.8-11 !)

rn-1 rn
lfH.20
18-121
18-122

\dedunrdelnurn_I . . . . .

18- l Z:i

Function O:H-1: Ddet.e Entry Given Node Name
ld1)r;funcddnamel
........ .
Function 04H: !lead Node .Entry Given Node Number
!dccfoncreadnumi .
Function OfiH: Read Node Entry Given Node Name
{dm·.funcreadnan.1e).

18-12·1

18·125

18·126

Function OHH: Read Node Entry Given Index

1decfuncreadindeJC.).
, . , .. , . . . . ,
Function 07 H: Iklete Ail Node Entries ldecfuncdelalll.

18-127
18·128

Contents

sxiii

Sen't'r
Block ISMBI l-'rotncnl .
. .....
Ext<'mh'd Function DOH: (±et. (\.irr1.~:nt Date and Time

Appendix A Support Code for Examples
Fi.le: SI PPOHTASl\1

l.8- L29
UH:30

;\-1
A.·l.

File: EXAMPLE.!.!.

A·ll

F:k: KYB.H.

i\. In

Vi!e: HB.H.
Fi.le; Y ECTClftSJ.·
VilP: RH C

J\.12
.:\- J.ll

.F'ik·: DE:vro.c.

A- l.il

A 1l

Appendix B 8028() 1nstn1ctioo Set
Appendix C

imd VT240 Termimd Emulators.

\rr220 En1tJhlt.ur t:uJd VJ 220 'f(T1ninaJ [JHferences
1

Selt:~cti(Jr1s

Font Sei.er_'tion .
\.:ornn1lJnie.~_1t~ons I)if-terences.

Se~:;.sjo:J JAJ,t=;g'iflg.

Ch;irM;ters

Chal_,r:cter Set.'"!

DEC MCS to ISO Ludn

8-bit Transition

_;\ddlUci11al \'~f~!~~O E'.rnulator f~scopP
U ser~Prctcn_;nr.e St1.pp!ernental Character Set
C-i\

Si::t iSCS!

xx.iv

Cun ir:n ts

Sulen DEC Supplcmeutal Coded Character Set (SCS) .
f4elc<:t lSO Latin 1 Supplemental Coded Charncter Set

C-7

\SCSi

C-7

Prirnary Devicf~ Attribute I.DAI .
Secondary Device Attribute !DA.I
Announcing- ANSI Confonnam:c Levels
Printing
Printer Options .

C-8
C·8
C-8
C-\J
C-9

Print Tt:rminiltnr
Print Size. .
\'T240 EmulHtor and VT240 Terminal Differences

C-!l
C-U
C-10

and Restoring Set-Up Selections
Vlden Differences .
Video l\fodes .

C-10
C- l 0
C- W

AutMm<it.ic Video Mofle Switching.

C-10

Si::; rolling .

C-10

No Control Hepresent<ition Mode .
Underlined Charnctors . . .
Line Attributes .

C· l 0
C J. .l
C· J !
C-1 J
C·.i J
C'.-1:2
C- I 2
C· l 2

Double Width Lines for Fast Text Only
Double Height/Double Width Lines for Fast Text Only
Comrnunicadons flifforeHces . . .
LAT Protocol Support. {Network 'I'ennina! Services; .
Session Logging .

Autotyping· Characters .
Keyboard Differences
Keyboard LEDs . , .
Alternate Char<:1ct.erli
No "Printer to Bost" M.od.e.
Clrnract.er Sets
D.EC MCS to ISO Latin-1 8-bit Transition
Cmnpose Sequences. . .
Additim1al VT240 Emulator Escape Seqtwnces
tlser-Pn:forc:nc8 Supplemental Character Set

C-12
C-12
C-12
C-12
C-12

C-J:j
C-1:3
C-1.3
C-J :3

(J)f;CAlJPSS! .. '

c-rn

Request Ui;er-Preforence Supplemental Characn-r Set
iDECRQUPSSI . . . . .
Sc)lect User-Preference Supplement;il Coded Charnct.~r

C-14

Set.ISCSl.

C-\.4

Select tlt;C' Supplemental Codec! Charact.t'l' Set ISC'.:ll
Select ISO Latlo· 1 8upplemcntn1 Coded Charact;er Set

C· 15

{SCSI

C·l6
Contents

xxv

P1·imar>> Devke .\tt.ribnte iDA!
Secoudary Device .Attribute ff>Al
A.nnmmr.ing· ANSl Cunfonnance Levels

C·l5

C-rn
C·16

Bibliography
Index
Tables
Phvsical Memory l\'l.ap .
l'ab~e ~~·-2

lnput/Output Address Map

1~nbk~ 2<3

lnterruµt Vector Map

Table 2-4
Table '2-i'i
Tab!0 ;p
T;,b!e :1 2

8--Bit Expan~~jot1 .Bus ·rrf'lnsfer ~rirnes

2-HJ

Expar:i.sion Slot P(';v,;er

2-10
3-2

Tabl<' ::ht

Table +.r
Table 4<2
Table .J-a
Table'.! J
Table :;,-'.,
Tabk ti-3
Table ~)-4

Luws ,
ivJ;c,,.;;t.er and Slave 110 Addre~u;es
thf~ Interrupt ContrnUcr

TJMA Heques1 Lirw i\ssig-i1m!.mts ..
P Tvl i\ (\1n troHer States .
DJ'\'IA.. Conanlkr and Page Hq~ister /\ddre~s "l>hlp
Heal Time Ckwk Address Map
Hcite Seh.;rti•:m Bits . .
H:TC DMcr Hegist1"r

(h)

3-4
4-~;

HTC /1ut•.>niatic Alarm Cycles.
Cuunter Signafs

Table G 2
T.f1ble t~-;J
Tabff' 7-!
T'!blfe 7 ~·

T«hle '/.4
Table 7 5
Tabic 1-6

8~?54 and
A\·ailcbi.e V<dp1; M:odes. , , ,
t\t,t.ributc BytP Ult Definitions . , .
Pages \R.OI\'I BIUSt .
Default VLT Contents .

VLT Contents lnr Video f\:lndes D l Hand 021 {.
VidNJ 1'n;;;essur l!O
l'fi:1.b1e 7-7 Cft["C: Internal HegiHters
"r;-1h1e 7 H Cirrc; Reg;_sr,(•r Value::; _
1\JbJP 7"-!) {);Jnr Seh.;rt
'Libk 7-10 Color Pal;:t.tes Sl'lected by CPS and SIC.
Table 7 -11
Vi den l'Vlndes
T'::ihle 7-· 12 1\-}o.nit.or InterfB:cn
T,:1ble 8- l Port .! Bi.r Definitfonz;
Table 8·l Port. '.c~ Bit Definition.;
Table 8··3 !\eyboBrd·!nterfocc l"ontroller Cmnrmmds
1\1ble 8~4 (Annn."':lanri
1---hr l.h::ftn.it1on~ .
xsvl

Cuntent7

7>H

7 20
7-21.
7-22

·;-26
7-27
7-40
·1-40

IHi
8-JO

Table B-5 Ll\.250 Scan Codes and Industry-stnnrlnrd
r•;quiv;ilent v afoes .
Table 8-H Scan Codes Translated But Not Used .
T<.ible 8-·7 L!<;:25n Keyboard Command Codes.
Table 8-8 L K2 f•O l\eybo;:Jrd Hesponses.
Table D-1 82!10 UART Register A<ldrl'sses
1~able Hw2
[nterrnpt Ident.ifiration
Table fl-:~ Baud Rate "fable .
Table ~H. Conummications Conrn,rtor Signals ,
Tt1ble ~-:) Printer Connector Signals.
Table H-G Modern Tdephone Line Cunnectm Signnls
'fable H-7 Handset Connector Sig1wls .
Table 10-l l\ilouse (\mnnand Summary .
Table 10-2 Serial Interface lkgisters
Table rn.:~ Baud Hate Table. .
Table IH DisJ;:ette Drive Controller llegisters
Table lJ ·'2 Diskette Drive Controller Conunands
Table lJ-:; Register Sets for Head Data Command
Table 1.14 Register Scts for \\'rite Data Command .
Tab.le l l 5 RBgister Sc•l:s for Read Deleted Data Cumrmmd
Ta bi<< I l·\i Register Si:t!i for Write DcietPd Data Cmnman<l .
Table l t-7 Register Sets lor Head Track Command.
Table l f .. ({ Hegister Sets for Head I0 Command. .
Table 11-U Register Sets for Format Track Command
Tabte i J .. J fl Register Sets for Scan Equ<tl Command .
Table H-ll Hegister Sets for Scan Low or Equol Command,
Table l !. 12 Regi.;;rer Sets for Sran High or Equal Command
Tllble 11- l :J,
Sets for Rccnlibrate Command .
Table l 1.-JA Register Sets for Sense interrupt Status
Command
Table I. l -1 f, H.egistcr Sets for 81wdfy Command
Table J. l- (}
Sets for Sense Drive Status Command
Table 11 · 17 fkgbter Sets for Seek Command .
TablP J 2-1 Hard Disk Controller Hegisters .
Table 12·2 Hard f)i;;k Controller Diagnostic Hesult Cod~~s
Toble 12-:J !VIem<wy Image of a Sector Interleave Table ..
Table 124 Hard Disk Controller Diagnostic Result Codes
Table L:l-t 0ietwork Interface Hegister·~ .
Table t;-1-2 LANCE C8Ra Hequired Values for the VAXmate
VVork!-'t<1tion
Tnble 14·1 VAXmute Powerup and 8e!Ffest Error Codes
Table 14·::'. VAXmate Processor Board .lumper~

Cont1Cnts

FH7
8 2J
8-22

8-80
!H!

n-rn
9-19

!J-:m
~J-2!

9-21
I 0·2'
HH3
l (). l l

11-2
lHU

l ! -21
l J-21
J l-22
l ! 22
Ll 2:.'I
11-2:5
I l-24
l I -24
H-2f;
l lc2fi
l l-W

] l-~'.G
1 .i-:rn

11-27
l l-27
1.2·2
12~G

12 .l8
Ln:t
l~~-G

L'l-lG
l.4-8
14-J ,i

xx vii

RO!VI BIOS
Vectors . .
Illterrnpt. 1 OH: Video I/O Functions
Toble I i~·.1 Video Modes .
Table Ui4 1\fode Doµendent Values for Set Cursor
Tah!c- 15-5 Dcfoult. Col.or !Vfap
Table l!'dl Color Mnp for Vide<i Modes D.!H and DtH
Table 15-i Hard Disk Error Co<lm;.
Table .l ;,.p. Hard Oi;;k Pm·fmt<~ter Table Descripthm .
Table 15 !! Diskette Error Corks
Diskette Pararneter Tablo
Table l.;)· .i J Cnrnrrnmicntions ContrnJ Block (CCR!

Table UH
Table 15-2

l)~scdptiun

Table 1f'.-J2

Cont.f'l1 ls

U\-:54
lG-40
J fl-41

1::;."'i8

BIOS P;1rnmeter Block Data.

Tahk· Hl·l4 .FNT File Structnre .
'l;;:f_de l ti l 0 .GHF F!h.3 Strud.ure.
TabltJ i)- l fl Keyboard Tables .
Tab1e 1G-17 l\eyboard Mnp File Structun'
Problnms for
Table 111· 18 Character~ {
COivJMAND,COM.
Table 1'3-rn Sort O!'der for !ndm;try·Standan! CharBctcr Set
(STD).
Tabk HJ-20 Sntt Order for DIGITAL !vlultiiwtionaJ. Character
8et 1!;ICS! ,
xxviil

i;;.io

CCB Buffer StnH:tnrc I

The HOM
HlOS ..
Tahle l'~- ! 4 Diskette P;ir8m•'ter Tabl\~ Descript.i0n
Table .! 5 1 f, Hard Di~,iz Para.nu•tur Table
Tahie G· 1 Cnn;or Control .lium.·tiuns .
Table li'><'. Eras,., Finict.ion ..
Table J fl{~ Sm
Hcndition Fnm:tion .
Table 11:; 't Stn: Mode Function
Tuble J. 11.r, Heset 1\loi:fo Function .
Tab!'.:' J fi.·G 1\eyhoard K.cy Reas:-;ig-mnem Fune! ion.
Tabhc 1fr7 Swndan:J l\loust~ Drive Functions .
Table HPl .F..;xte1~d1:d JVkHJS<' Driver Functions
Table J !HJ Vide'.'
and Modes Supported hy
MOUSE.SYS.
Tahle 16- iO f<'.'zte11Sions to Int.(:r.nipt. l OH !•;GA Funrtion.s
~Table J. 6 .. 1 r
f~(1.,<\ I{<-~gJstt~r
z~nd A.ssociated
Tati'le 16-.t 2 Il:trd [Jisk

Table 16-18

l f,. 1
15.9

1t~·Jt~7

W-ii

llVi

HH'-

liJ Ll
Jfj.14
1 G·- l ;:t

lG-a4

1;; 40
l. (;-lb
JH-1()
t(i~fiO

Table 16·21 8ort Order for lntorn;:itional St<indards
Organization Character Set USO! . . . . , . , . . .
Table Hl-22 Sort Order for French 7-Hit NEttiona!
Replacement Character Set WR7} . . . ,
Table 1fi-2:J. · Sort Order for German 7-Bit National
Hep!aeemcnt Character Het KHl7) . . . . . , . . . . .
Table l7·1 Kf!yboani Messages Transmitted by Jl,lS-Windows .
Tahle 17-2 US to ASCII Translation Table .
Table 17<1 Danish to /\SCH TranslaUun Table.
Table 17·4 Finnish to ASCII Translation Table
Table 17-{f Fnmch to ASCII Translation Table.
Table 17··f:i Frnnch Canadian and Bilingual Canadian to ASCII
Trmislation Table. .
. . . . . . . , . . .
Table 17-7 Oerman to ASCII Tnmslation Table .
Table 17-8 ltalian to ASCII Translation T3ble .
Tabk' 17-9 Norwegian to ASCII Translation Table
Table 17-Hl Spanish to ;\SCH Trnnslation Table .
Table 17·11 Swedish to ASCII Translation Table .
Table 17-12 Swiss French to ASCH Translation Table
Table 17.1;3 Swiss German to ASCH Translation Table.
Table J 7-14 Tnmslation of .J'\NSl. Set to OEM Set..
Table l7-l5 Tnmslntinn of OEM Set to ANSt Set..
Table 17·16 INT lOH Functions .
Table l 7.. J 7 Supported Video Modes . . . . . . . .
Table l 7-17 ('baractRr Sets Supported by Each Printer.
Table 18-t .Interrupt 6D: Dat.alink Fum:tions.
Table H».2 Datalink Return Code11 .
Table 18-'.; Rccomma:•nded Values for DataUnk Parameters.
Table ! 8-4 LAT Call Back Houtine .
Table 18·5 Interrupt. G/\.: LAT Functions , . , .. ,
Table 18-6 Session Control Block Fields . . . . . . .
Table 18-7 DIGITA.L Session Control Block Fields
Table l.8·8 lnterrnpt. 2A; MS·Ncrwork Cmnpatiblc Services
Table 18·\l lnt.er.r11pt 2A; D!fHTA.L Specific Session Extensions

Table 18-10 Error Codes Returned by Session .
Table l 8·11 Session St.atus Buffer .
Dt;C MCS ·ASCH Graphics Set lfVil.
DEC MCS - Supplemental Graphics Set
Table C-~1 ISO Latfo· l Character Set 1{1-7)
T;1bk C-4 lSO Latin-1 Charaetcr Set IS· U>) . . .
Table C·5 flf.C Sp1:drrl (1raphics Chrrract.er Set
TRbl.e C·l.
Tablf! C->~

16-HO
17-12

17-H1
17 2l
ll-·2:3
l 7·2'J

17 '.:;(}
l 7 ·8 ;j
17-'.30
17'.H)

17·42
J 7 ..45
17-4.8
17-fd

1 7 .!)f)
17-5S
i 7-80

17-8;!,
JH\4

1812
IR·l ::\
Hl-17
J 8-\')2
18·11G
18-87
18-Sfl
18·92

H\-f:J2
18·B4
18-100
(' 18
C-lfl
C-20
C-21

Figures
Figure 1·1
l <?

l~ig-ure

Figure 1-:l
l-1
1--:)

.! .!)

F·igure 2-1

Fig·ure :3.1
Fig·o IT' ;~ • Z

Figure ~i-3
Figme G I
Fi~~ure 7-l

Fif5ure 7~2
7 .. a
Figure 7 ··1
Figure 7·:'.•
Mode.

Base Collfigmation \Vorksf.atlon . . .
Wod<station With Instailixl h~.pamiion Box .
Optional 80.£87
Opr.iona! T\vo ~.fogabyte DRAl\:.l Module . . .

Optiornll Modem .Mod11k .
B!ock Di,1gram of WorksU1i.ion Compoiw.nts.
8-Hit And HJ."Ait Hus Connectors
Priority Before notation
Priority After H.otni.k•n . . . . ..
l n tcrrupt Sequen<:r· .
Three Channel Counter/Timer Block Diagr(;lrn
Block Dingram of the VA.Xmate Vl.deo Controller.
Ch:in1r:ter Buffer .F'ornwt.
J\hm10ry Organization for :J20 x 200 4 ..(\1lor 11.fode .
Pixel to Bil-Field J\fap for 4-Color Mode
tor a20 x 200 1 fl-Color

Pixd to Bit-Field Map for JfH~ol•x Mode .
Organizatinn for G4f! x 200 2-Color rv!.ode .
Pi"d to Bit· f;'i•"ld l\:lnp for ~>Color I Munochromd

1--5
2·.l J
;~. J 'l

8-l4

:t-20
(;2

7·6
1-l l
7-11

'H2
7-1:3
·~

Fig11re 7- ! 0
Fli(Urc 7 .. .1 .1
fviode .
7 ~. 2
F'igure

for G4. 0 x 200 4-Color Moi.fo .
Pixel to Bit-Field 1\fap for --!-Color Modl' ..
Memorv Orgwi.ization for li40 x 400 2-Coior

Pixel tn Bit·Fif·ld !\fop for 2·Co!or J'vfodP ..
for (140 x 400 ·~·-C• •lor

i.3

7 J.4

7-1 ~
1·-.1 G

Mode

7 l 4.
FiQ"ure 7-l f;
,'\:lode.

Pixd to Hit-Field .Map for 4-Cn!or f\fode . . .
Org·b.nizatinn for 800 :-:: 2i.i:! 4-Color

7-l.U Pix-el to Bit Field
8· l
Pmiition L-ib(;ls.
ViJ;-,'1.<rc 8·2 U.S .'ll.K. heyboard
(:!.;1
C1madianiEnglish
Fig11rn R··f· Danish
8·{;,
r'hu1i.sb !(cvboaTd_
8~G
FrPnch;"Can•·1dinn l{{!)tbnard
8-'i"

Figure 8-8

8<1

7-17
7. i.7
8-1G

8.:n
fH4

r.:·:n~nc.h

8-37

Cter1nan//\J1~~t-rian

8 'lH

Ht:brPw

8-~1n

Figure 8-JO
Figure 8 .l l
Figure B-l2
Figur0 8- l ;3
Flg·ure tl-14
Figure 8· l !)

f talian J\cy bmird ,
Norwegian Keyboard
Spmiish .Keyboard
Swedish Keyboard .
Swiss/French Keyb<mrd ,
Swiss/Gernwn Keyboard
Figure J0-1 VAXnrnte .Mouse !Part Number VSXXXi
Figure l'.H Descriptor Hings , , . . .
Figure 14-1 Test Sequence - Processor Board
Figure 14-2 Test Sequence· IIO Board . . .
Figure l4 .;'\ Test Sequenct' · Options .
Figure 14-4 Test Sequence .. Initialization and Bootstrap
Figure' l 4-6 VAXmate Configuration Screen .. , .
Figure J ·+·G VAXmat.e Prot_•essor Board ,Jumper Configuration
Figure 15-1 LK2f)O I<::eyhuard Layout
F'i!-,'l.l!'e .Hi·i
MS-DOS llHte and Time SLrncture
Figure 17·1- Keyboard Position Labels . . .
Figure l 8-J VAXrnate Network Components_
Figure 1i-\-2 1\falticast Address Format ..
Figure Ji:\-:'! Session Interface Implementation.

Contents

8"!0
8-41
8-42
8-43
8-44
8-45

10-1
13-28
l 4-2
14.4
l4-5
14 ..i)
.l .:1-12
14-14
i. 5-I 03
l 6-4

17-H
18-2
18-7

J 8-8!)

xx xi

Preface

i\udience
This m;rnuil.l provides rnten'ne<.! material about: the VAXmate workst!ltion. H
u;vic'rs
programmable comprnients, the firmware, and .several MS·DOS re·
lated environments. The material and its presentation are directed tu expe··
rienced pn.igr<1mm.crs r>r soft:;vHrc

Manual Organization
This m&nuril i.;; d.iv.ided i.nto tour parts and 1~ppendixe•r.

l provides an overview ni: th(; \' AXmatc workstiltion and options!
" Chapters 2 through U introdw:c the VAXmnte' workstation
prngranm1able hardware devices. Earb d1npter dis.:usses a single hard·
ware programming task. such as video input/output ll!O!. external inter·
rnpt. prnc·e~si1tg. or S•!dal comrnunication~; and includes the following
intorm<ition:
A hrief dt•vicc descr.iption

A list ul additional refercm·cs
A tksniption of the progrnmnrnblc hardware rngistns
;\ programming exam.plc
r\ discussion of the eKamptu

The
an; writtun in the C progrnmming langciagt> t(I reduce the
siu• ot the exmnplrs and fottis on the t:a<ik rather than th" det.ail required
by the fong11Hg-.:?.

•

l 4 describes the power··np di.<1gnostics and sy5tP.Hl stnrt.up .

Chapter u, describes the rend-only rnemorv hnsic input/output system
01011.;J BIOS!.
The appeHdixi:;s cuntnin ;:idditional intonnarion. including a hibliogrnphy ol

other asdul publication<;;.
Prefm·e

xxx iii

TerrninoloKv
The foHowini::.· rerm0 :ire used throughrn;t Lhi;; nwnual and are defiiwd ;rn
tollov·.,:s;

Definition
The 1;omputer industry recogninJs two open Drehfrccturcs
as
st3ndnrds. the IH1V! PC AT bus strncturn find
the MkrosoH disk
svst.em ~MS~DOSr. Nloreover,
[l defined set of HOivI fHOS
rnnn in<fostrv·st<:<ndard rcf~,rs tfl cnninatibil·
with iJ1ef'e arch it.ertures.

Resciverl
,c\ v;ctila blc

rro avoid C";infvs!nn H!HJ incotnr_1atib.iHtv. the use cf certain
itmns such us mcmon: ::;pncc. i/O sp<.i.cr,,
vectors.
and ROM BIOS
·
or n·tun1 vahrns must be
··Iearl•r' defined
t!1rcc: categorfo;; define t.hosc item'>
tb<l t ~lo noL h;ivo a
ln future !mrdwarn or i;oftware r..;:lea:'iC''·
DIC;rrAL may defl.1w a
u'>e hir this
iteiiL Hardwa~·e or suftwarc applir:atinns
that use thi:s item rnav not work wlt.h
fnnire n:lease<>.
,,
H.ardwnre i.w software applications can 11~:0
this item. DIGITAL has thifined the soc·
cific USf' ,,f t.his it.~·m a;; avaHah!.~- tur ·
1-iardvvare or soft'tvart! ,c1pplicDtions can ust;

!.his .iwm. However, then~ remain» some
risk that DIGITAL nwy define u
u.;;c for thl.s item.
•

Federal Communications Comn1ission
Radio Frequency Interference
Class A Computing Devices
This equipment gener;:ites, uses, and nrny emit radio frequency energy, The
equipment has been tested and found to comply with the .limits for a Class J\
computing device pursuant to Sub-part .J of Part 15 of FCC Rules, whkh an•
designed to provide reasonable protection ag·Hinst: such radio frequency interference when opernted in a commercial environ,ment. Operation of this equipment
in <1 residential areu may r:ause interference in which case the ustT at; his own
expense may be required tu take measures to corre•:t the interference.
lf this equipm.ent does f'ausc interference to radio or tclcYision reception, which
r~m

be determined by turning the equipment off and on, the wmr is encouraged
to try to correct the interfore1.H:e by one or more of the following rnethods:
•

re-orient the receiving antenna
relocate the computer with rcs1:x~ct to the receiver
move th(~ computer aw1iy from the receiver

•

plug the computer into a different outlet. S(l that conrputer and receiver
arc •m different branch 6rcuits.

11 necessary. the user should consult the deDlcr or trn experienced nitlio
.rind television technkian for additional suggestions. The user may find the
booklet, Hmu w ldentifv and Rf?sol!'e Radioi1'\/ l11ter/Prence Problems.
prepared by the Federnl Communications Commission helpfuL This booklet ts
iw<iilablc from the U.S. Government Printing Offire. '\Nashinf,rton, DC 20402.
Stock No 004·000-UO:lBR-f).

NOTE
Shielded cable':< Dre pnivided for use with this device. Should <my
•~ables be replaced or added for any reason, these cables should
he the same ll1'. or with higher 5hiekHng capahi.lities. Hum those
provided
Digital Equipm<ent Corporation.

Prdacc

xxxv

Chapter 1
V AXmate Workstation Overview
This chapter describes the VA Xm:•tP workstations physic:il appeanmce, base
configuration, optional components. nnd the logical rdationship of the
components.
The VAXmatc workstation is a high··performance, standalone. desktop pmsona!.
computer t.hat. execute;; industry··&tand11rd software. The integral Ethernet inh'r·
face allnws th<:: V/\Xurnte workstation to com1mmh:ate on a network. The hard
di>;k storage, provided in the optional expansion box. allows tbe VAXmatc
workstntion to b\; <1 server on a network.

Base Systen1
In the base r:onfigurri!:ion, the VAXnrnte workstation bas three units:
•
•

Svstem u.ni1·
1<,eyhoard
Mouse
t ·J shows a bast' configuration workstation

\! AXmate W orlrntutfon Overview

1- l

In the bast? configuration, the system unit contains t:be foll<)wing
coniponents:
•

8028G

"
•
•
•
•
•
•

One megabyte of dynmnic nmdorn·acf'ess memory lDH.1\f1lr
Vid•~o monitrir iind controller
Diskette drivP. ;rnd c1mtrnHt:r
Lthernet conno!Jer
I<t~yhoHrd IntPrfacJ_~ contrnJ!er

•

Event timer
Rt'a[ time dock and <;ak:ndar
Sn·io l c<mrnurnicmions poi:!
Serial printer port,
Serial rnou~~e 1)ort
S µeak;"r

•

Po1v 101.· supply

•

•
•

l· 2

VAXmatr; Workstation OvPeview

Optional Components
The workstation provides for !;he fol.lowing optional components;

" An e:qiansion box. purt number HCD31-EA. t.hat attaches to the bottom
of the system unit. Figure 1·2 shows the system unit with the expansion
bnx att1whed. The expansion box contains an <1dditional power supply. a
battery, a 20 megabyt1) hard disk drive and nmtroHer. and two irn:!ustrystandard expansion slots
•

An 80287 coprocessor. part number FP287. that. installs in the system
unit. Figure J..;:~ shows the 80287 coprocessor.

•

A two megabyte DRAM rno<lule, part number PC50X-AA. that installs In
the system nnit. F'igure 1-4 shows the two rnegabyte DHA.M module.

•

A modem module, part number PCf10X·!\1A. that installs in the system
unit. Figure 1-5 showR the modem module.

Figur':' 1-2

\V!Jrksiatl.on With Installed Expm1slun Box

VAXmutc \Vorkstatfon Overview

l ·· :3

l· 4

Figure 1.<!

Optfonal 80287 Coprocessor

Fignre 1-5

Optimrnt .M.odem..Modult~

VAXmatc Wor.kstntion Ovm·view

Fi1.;i1rn 1·ti shows the relationship of the workstation romponent.s. The haUory
is present only ·when an expansion box is installed.

D
0
'

.
.

Figure .l ·G

Block Diagnim of Work!'itRtion Components

VAXmutc Workstution Overvi€'w

l. ·· fi

Chapter 2
V AXmate Microprocessor
Overview
The VAXmat-t1 microprocessor is an Intel 80286 central processing unit \(;PU•.
The CPU is a high-perforrnance. 8 !\Ufa microprocessor with a lG-bit external.
data patb and a 24-bit address path. The CPU provides rwo mndcs nf oprc,ration. real address mode and protected virtual address mode.

Real Address Mode
On powerup, the CPU operates in real address mod(' . In real address mrn:!e. tlw
80'.~8() CPU behtwes as thnugh it is a fast 8080 CPU. It is limited to the l
Mbytc address range of the 8086 CPU. In mat 11ddress mode. the ROM is vccessed in the address range (ff'OOOOIHWFFFFH.

Protected Virtual Address Mode
In protected virtual addn•ss mode. the 8028fl CPl_T can access Hi Mbvtes of
phy:sinll memory and l gigabyte of virtual memory.

The HOM is redundantly ma.pped t.o t.wo physical address range<;, OFOOOOR
OFFFFFH and FFOOOOH-FFFFFFH. Therefore, in protected virtual address
mode, the 8028G CPU can access the HOM at either physical address n1ngc.
However. the .majority of the ROM BIOS code is not val.Id in protected virtmd
address mode.
The CPU uses the keyboard interface controller or a double exn~ption fault to
rnset to r(~al address mode frorn protected virtual address mode, The keyboard
interface contwller is discussed in Chapter 8.

VAXrn1.1t.e JVUcroprocessor

2- l

Coprocessor
Tl~e

coprflU'Ssm for the V.t\Xmate workstotion is an Intel 80287 proc·
lt i;; a high·ptn-forrnanco. numeric proce%or that extend;;
to include fln;c;ting-point, t:"'.t.en<lc{H!lt.eg;er, and
codPr:i de•.·irnn.l

extension
the CPU 1fatn

f:'.·'·SOr

Additional SourcPs of Inforination
The

Jntel Corporati•)n dncurrwnt& provide additional information on
lnirodru.,:t~'o::

to the i~·41J~\ 2/·:e H-1<ubiicnt.l(Hl Nurnber 2J o:~08J
i41'.Y 28ii llorrfo•,ne Fle(•'rOu'<' Ma1ww' \l-'ublkation NumbPr 2107GOl
1.APY 28t:
lfrferencP Jfomwl IPublieatlon Number 2HH91l)
fl;;ndbool, 1Puh!ic11thm Number 2:l0843)

Men1ory Map
The base confir{urnrfon work8tatiun hns 1 Mbyt,e of RAl\I and H4 !\bvtm; of
HO.M. An optional nwmor,· m.odule can be added without an ex1,mnslon box.
Tahle 1 describes the VAX mate 1Norkstation 's phy8ical menlory map. The .i
Mbvte of FtAl'.·i is divided into thn;e noncontiguous blrJcks. tn Tuble '.?--1 these
blocks iir•~ labeled BLt.>Cl\.l BLOCKZ. 1md 13LOCJ\:3.

Tan!e 2 i
From

Physkal M.enwry .l\fap

Size
iByt<>><)

O}lFFFFIJ

G4lH<

OAUPOOH

O:\FF1FH

!HI\

He served

UBOOOO.I)

OBI'.FF'Fll

G4K

Video i-tAM.

OOOO!lOH

video mode setun, the video
d_ynntnica!l_y n1H~J1P(~d, <ln}y
th<: vitk'n RAM reauircd hy tlv.> cur·
rt•nt video mode is. w·-::cssiblc.
OCOOOOH

(lC:FFFFH

OUflOOOH

OEFFFFH

1.21rn.

DlCHTAL priviitl; HA.1\1 (BLOCK2)

t)fOOiJOi!

OFFFVFH

G4K

Svsh:m ROl\1

.JOOOOOH

EHTFFH

l 4:.1aH.K

F(H)00UH

F.IFFFFH

128E

G·IK

1\\<1ih1b!e tor options wlt.h
1\01\l

FL\Ivl sp(ln."

llest·rved R.i\Jvl space

F'.!OUOOH

F5Ff·Ti'll

21;GK

Ff>OOOOH

F7FFFFH

128.K

R<;served TIAf\1 spar•:

FSOOOOH

FFFFFFH

4·!8K

ffoserved ROM space

FFOOOOH

FFF!;FFlI

04K

Svst.ern ROM (rmiundantly
tn>m OFOOOOlli

Input/()utput Address IV1ap
Table. 2°2 describes the Vi\Xw<lte worki;rntinn's !iO addre<;s
l!O ports hav•c an industry·standvrd assignrrnmL Hecognition
mem does not indic0tc that, the 1fovke is present, in the workstat.inrL

Frt.HH

OOOOIJ

OOlFH

0020H

Device

D MA controller
8250A

OtHOH

OOGFH

0070H

0077H

007&H

007.FH

0080H

{)()<}F}i

OOA(}H

OOBFH

OOCOH

OOPFl.l

Interrupt contro!kr #I
Timer

D.i'vtA page

OOEOH

l.lrF,ssigned

OOFOH
OOF!H

OOF2H

OOFFH
0100H

OJEFH

OJFOH

01FSH

80287

!Vfoth i:nprocessur

nJFFH
H200H

0?07H
0277![
Pnral!f~l pri1tn~r flurt #?

02F7ff

Serial por: Ii~:

modem

Table 2-2

Input/Output Address Map {cone}

Prom

Devke

Description

0300H

031FH

He-,erved

0:320H

0:3GFH

Unassigned

0%0H

o:rnFH

Reserv<Jd

mnoH

0377H

Unassigned

0378H

0~'7FH

Parallel printer port If l

0380H

038FH

Reserved

03£\0H

O~HWH

lJ nassig-ned

o:lAOH

03AFH

Reserved

03HOH

O~~BF.H.

He served

O:!COH

03CFH

Reserved

03DOH

!li!DFH

o:n;rm

O:lEFH

oaFOH

o:wrm

o:~FGH

oaF7H

oaFEH

o:H-TH

04UOH

OBFFH

Unassigned "'

OCOOH

OClFII

System CSH 1

OC20H

OC:WH

Ethernet HOM

OC40H

OC5FH

OC!lOH

OC7FH

G84i)

Graphics video controller

Unassigned
PD7G5A

Diskette controller

82f,O

Serial port # l

Hard disk and diskette nmtrollcrs

2GG1

Universal Asynchronous Hecelver:
Transmitter iUARTt for mouse p<.n-t
Network Cont.roller and lnt€,rfoco
Specia.l purpust" register

OC80II

OOHH

OC9FH

OCAOH

OCA7H

OCA8H

Ol!FFH

Resened

OEO(IH

FFFFfI

U mrnsigned •

Hescrved
1'l2ii0

Integral serinl printer port

lndustry·standard. processnr-board, 110 ports in the address range OOOOHOOFFH respond tr.o these IiO addre.~ses. Therefore. 110 to the expansion
b~>s in this address range is trnrlc!ined.

Interrupt Vt:~ctor l\llap

'The f!r.?s~_."}£/j}f~'.:";1~- ;::oh_JnH~ ~.dt:ndJie0 th.f"~
1_.'f:ctor.

ere nnt s~~1 -,,·1(C~d
return d.H._E'T~~

B fOS serviced

lnwrrupl

T.ype

Description

Sr~rvke

OOH

Divide by zero

!HIST

OIH

!<~

Single step

lRf~T

0'.:'.H

Nl'vl[

ROM RIOS

0:10

Breakp<Jint ~Used by DEBlJG)

IHET

04H

Overflow

!Hf;T

o;m

Print Screen tu net ion

ROM BlOS

OHH-07H

Reserved

IHI'!T

08H

Timer interrupt service HRQOI

HOM BIOS

OHH

Keyboard interrupt service llHQl l

R0l'v1; BIOS

OAH

Reserved ilJU-,!2 interrupt from controller 1121 IHET

OBH

S•~rial port 112 !A.;;ynd1ronousf lm<.Hk·m
option/ tJHQ:·n

lRET

OCH

Serial port #l tA"!ynchrnnousf HRQ:ll

ROfvl BIOS

ODii

Unassigned URf}f>l

IRE:T

OE!I

Diskette interrupt s•1rvicr) URQm

Ror..1 RIOS

OFH

Parallel printer port # 1 \Hl~f/1

1RE~T

!OH

Video VO

ROM BIOS

lUl

s
s

Return config1mition

HOM BIUS

Hef:urn rnemr.iry size

ROM BIOS

lHskett.e and h:ird disk I:O

HOM BIOS

t\syncbrormus communications I/O

H.Otvl BIOS

E'.YU:nck,d RO!'v1 BIOS functions

HOM BIOS

l\eyboard HO

ROM BIOS

Printer Ont.put

HOM. U!OS

1.tH
1;·\H

l·tH
l fi!I

l!JH
1.ni

s
s
s
s
s

I.SH

·'

Invoke network booUl\:la.intenam:e Ope.nition
Pr•:itoi:ol ~ l\lOPi

ROrv1 BlOS

Bootstrap

ROM. BIOS

~:--

V.:\XmntP Mkroprocessor

2- 7

TubJ.e 2-'.l

Interrupt. V<'ctor Mnp (cont.I

Interrupt

Type

De~wl'iptirm

Sel'vke

lAH

Time of day

ROM BIOS

urn

Keyboard BHEAJ{ vector

rrmT

lCEI

Timei- tick vector

lHf~T

lDH

Video parameter tablo

noM mos

lEH

Di-;ket.te pannnet.ei' table

ROl\.1 mos

! Fl!

Graphic<;. character table 1.Charaner codes
80H·FFIH

ROM BIOS

20H-:1FH

Reserved for MS-DOS

IH.ET

40H

INT 1311 redirect when hard disk in use

HOM BIOS

41!.1

Param0ter table point.er for bard disk 0

ROM BIOS

•l2H-4fiH

Heserved

IRET

Pau.mwter t1;ble pointer for hard disk 1

no~1

RescfVf'<l

IHET

Avail:ihle for app.licntion or u<;er program
interrupt:.

IHE'I'

47IH>FH

HOH-67H
fiHH-6FH

70H

71 H

mos

IHF.T

11-•'al time clock interrupt 1IH.t:;l8I

ROM BIOS

Hedired tc1 in1.errupt O!\H · Old IHQ2

IHET

i1H<¥l1
72H

74H

EUwrnet runtrolir:.r UHQ l Or

HOl\1 RIOS

Serial printer port i!H<:;ll J)

HOM BIOS

Mouse port llRQ12i

IHFT

807-87 error (IR(tl'3!

norvr mos

75Fl

7flH

I-ford ifo;k 1:ontrnller OHQlAi

nofl.I nros

771!

Unassigned llHQJ &I

LRET

78H·7FH

!HET

80H-FOH
Fl H-FFH

IFU:;T

Bus Timing and Structure
The 8 MHz dock rate results in a l2t> ns processor cycle. Normal operation of
the 80286 CPU n:quires t·w1J processor c_\Tles. \Vith zero wait swtes. o read or
write <'.yde requires 2f>0 ns.
Th<irc are three th•ta bus structures:
•

A l 6--bit local bus

•
•

An R·bit expansion bas
A lG·bit expansion bus

16-Bit Local Bus
The local bus conneds the C Pll to on-board memory and on-board peripheral!::.
One wait stat.e is added to local bus memory transfors, resulting in a :J7G ns
hns cyde. Two wait stfltes are added to local bus input./Putput H/Ol transfers.
resulting in a 500 ns bus cycle.

The\ HA~l 1Jccess time is 1fi(l Jl'>. The HOM ac.ee.~s time i~ 250 ns.

NOTE
ln assembly language progn.imming. directing tw<• or more contiguous IIO instmction1> at the same device m.ay not provid1~
enough time for the device to respond. This is possible because
peripheral. devices respond more slowly than the 8028G proces·
sor executes. A jump instruction consumes processor cycles and
dears the pnwcssor pre-fetch queue. Thus. jumps to successive
110 instructions provide t.he required response time. The C lan·
gt1ag'' l!O function<;. commonly named inH imd ou!O or inµO and
out.sO, provide enough response time b1xa11se they cont.ain sufficient overhead in the calling sequence.

16·Bit Expansion Bus
The Hi-hit expansinn bus supports word transfers to memory and 1/0. One wait
state is automatically added. rnsultlng in a ;n 5 ns bus cycle.

8-Bit Expansion Bus
The 8-bit expansion bus supports bvte and word transfers to memorv and 110.
vVord transfers are controlled by h;~rdware. which issuf:s two sequential byte
transfers \low byte first and high hyre sernndl. Table 2-4 describes the bus
cycle times for ~dl trnnskr types on the 8-bit expansion bus.

Tnble 2-4

8-Bh Expansi11n Bus Trnnsfer Tim.es

Type

SizE>

MemmT

Tinw

Wait States

7ii0 ns

.l\fomory

\Vord {two, 8-bit tran;;f;ors)

1GOO ns

JIO

Byte

1125 ns

Word !two, 8-bit tn;1.nsfcrsi

22GO ns

l·l

Expansion Box Technical Spf~cifications
The VAXmate expansion box provides two nxp<Jnsion mndule slots. Ear:h slot
accornrnodat.es a single expansion module. If ;i mother-rfoughtt'r board h: used
in one of the slots, thr-n both slot areas will br,, u'>cd and it will not be posslble
to add a seumd modi.Ile. Table 2-c) shows the ampcr;1g-i: \current) and 1v;.1ttag·e
values available for 1,:arh slot. Ear:h slot has m1 8 .. bit and a l H-hit bus connector.
Figure 2· i. shows the
mmi.bcrs ;:ind sign;1! 1rnmcs for the R bit ;rnd Hl-bit
bus connect<,1r,

Tuble 2-5

Expansion Slot Power Roting!'

Slot

HUV

+ J.2.l.V

·12.0V

·5.0V

Wntts

OPT·l

Lrno
i.:rno

0.100

O.IOO

0. !. OD

H.1340

0.100

(UOO

0.100

H.fl10

OPT-2

Expansion Box Operating Ranges
,,\.mb!ent Operating Temperature: l!) C 159 Fl to ;J'.' C {HO Fl

Rofatin' Humidity: 8"{ to 80',;\

8 Bit, Bns Connector

GROUND
RESET H
+5V

IRQ9 H

1:~
jln

!B4

-.'JV

I BS

DRQ2 H

IB6
jll7

-12.V
O\lS L
i-J2V

GROUND
MEMY I.
HEHR L

----:i-l

jB8

lB9
IB10
jBll

812

l.G-Bit Bus Conn<?f'tor

1/0 CAK L

SD7 H
SD6 Il
SD5 H

SD4 H
A6 I SD3 ff
A7 ! SD2 H
AS

A8
A9

I SDl ll
I SDO H

AIOI 110 ROY lJ
A11 AEN fl

rov L

1Bl3

IOR L

IB14

OACK3 I.

!B15

A12! SA19 11
AU! SA18 H
Al41 SA17 H
A15I SA16 JI

DRQ3 H
DACKl L

IB16
Bl7

A16! SA15 H
A17 j SA14 H

DRQl H

1Bl8

A18! SA13 II

REFRESH L B19
CLOCK U
jB20
IRQ7 H
!B21
IRQ6 H
B22

Al9! SAl2 H

IRQS Il
IRQ4 fl
IRQ3 H

.B23
jB24

A23
A24

I B2~)

A25

DACK2 L
TIC H

ALE H
+5V

OSC H
GROUND

I
I

A20l SA11 H

A2ll SAlO fl
A22

SA9 H
SA8 H

.
D3

IRQll H
1RQ12 H
IRQl'.> H

101,
jDS
I06

.
C'.I

UAl8 H
UAll H

!D7

ID8

DRQO H

jD9

DRQ5 H

**!DU

**I rn2
DRQ6 H **IDD
DA(,'K7 L **I D14
+5V

DRQ7 H

**IDl5

MASTER L
GROUND

UA20 H

UA19 H

IRQ14 H

DACK6 L

j UA22 H
UA21 H

DACKO I,

DACK.'> L ** IDlO

I EMEHR L

CJ 0 I .EMEH'W l,

cu I SD08 H
c12

CB
Cl4

SD09 ll
SDlO H

SDll U

Cl~.)1 SD12 H

SOU H
1016 Cl6 SD14
H

Dl 7

Cl?

1_u_1~___c1~j SD15 H

** Not Implemented

SAl H
SA6 H

B26

A26

B27
B28

AV SM H
A28! SA3 H

B29

A29I SA2 IJ
A30I SAl H
SAO H

IIUO

SBHE I.
~DD...12___cc:21·."·-i1 UA:n
R

HEH16 L
l/016 L
IRQlO H

SA5 H

l~32_ __~~lj

Figurf'." 21

8-Bit unrl lfi·BH Bus Conueet<m;

VAXmatP Mirroprocessnr

2- lI

Chapter 3
Interrupt Controllers
()verview
The VAXnrnte 80286 central proce<;sing unit iCPlH hos two interrupt input
lines, the Non-J\faskable Interrupt tNJ\H.l and the Interrupt Request HNTm.
\'Vhen tlwse hardw;H"e inputs arn active, the CPU suspends execution of the
curnmt prngrnm. and beg·ins exeo1lion of an interrupt hwullf-'r. An interrupt
!umr/li>r is a program or progrnm segment that responds to a specific event.
This allows an inmiediate response to asvnchronous external events and tbc
segn.?gatlon uf program responsibility for handling those events.
Tlw interrupt input lines are assigned to different dasses of events. The N MI
is dedkated to two ratastropbic events, memory parity errors and liO bus
nrrors. The INTR is assigned al! other external interrupt sources. sm:h as
diskette and bard flilik controllers, serial and parallel porl.s, and clocks. The
rmisun for this division is the way the CPU implement.s the two interrupts:
The NM I has a higher priority than the INTR.
•

The CPU h11s no way to disable the NJ\,H input

The CPO provides handshaking protocol during I NT!t processing, but not
dur\n,i:; N MJ pro(:essing.

" The NMI gerwrates only one interrupt vector. which is fixed
Bt>tausc the CPU does not provide handshaking during NMf processing, the
CPI.) ~:annnt r:o1T1m1rnicvte with an i.nt.crrupt controller. Therefore. the NM[
so11n·es are connected directly to the NM l input. To determine die source of
the int.£:rrupt. the NJ\.H interrupt handler mu<;t read the stat.us out.put of the
S(l\lr<:e:L

Interrupt Contrullcrs - Hardwurc Dmwript.iou

Tht; l NTH inpnt is buffered
ccntrnller" rcd;Ke the CPC

·rh~-~-~./

•
*

rrhtnt

controllen,. The interrupt

rcsoh·f_: the nrinrit\, ~A 0irnnit-£-1nt:n1L~ or
conccntrate-'nndti{~d_t:
i.nto -one S(HJrce

the vector nun1ber

i_nterrupt handler,

inu:·rrupt requests, :-l'ht~
F:ach int,-:::tfU_pt: C(!nt.rnHer is
rn inputs are !abf'lod IHQO-JHqIG. Cnntrnller buffors I HJ~O-IHJ-fl and control·
~lre physirnlly ide~u.\c;)L du: lntenupt
!er 2 buffers
·nJe 1mtµut of 11mtrolkr :'. Hhe
slnve} is co1,1nectt~d r;o the IHtJ~~
of controBrr
lthe- 1nast.erL TrhP 01Jtpu:t
of the :w;scer i;, f'{arnected U.• lhP INTH .input of ttH~ CPU. Tabin ;{-1 sh<.1ws .,,u
\,f thP If\(~ inputs.

Prlnritv

ConLrollcr
ill MASTER

{:nntn)!if•r

F~vent

IHQI!

Soun:<"

#'..: SIAVE
rirncr output. {}

IHQJ

Sl.a\·-e int1~rrupt control1f~r

:.u

IH(JK

:-u

l fli,J!/

Sofl.warn rndlref'l.ion to l

!H.G{tfi

LANCE WrherncU

m~~11

Snrial pr.int.el" pnrt

lHQU
errc•1'

fHf>l:l

rn.q14

Hard rli::k drive cont.rl>lkr

!H(-l;'l

IHQ,t

/\vtdiahJe. 8-bit bus

Interrupt C11ntmlln& · H<1niware Description

Additional Source of Infor1nation
The following Intel Corporation dPcument provides 11dditiorwl informntirm:
Co11ipone11ts fi1mdlwok IPubli.cation Number 23084;{)

Read/Write Control
The 82;19A Interrupt controller has the following registers:
lnifialization Command \Vords IIC\,VJ - There are tour inithi!iwtion cmn·
nrnnd words \ICW J-l('.\V 4L They csl<iblish the opera tin~ condit.ions of :Jw
int.Prrupt. rontnil!cr and ;ire written only during syst\'m initialization.
Operation Command '\IVords IOC\·\.') · There are thrn(' operntinna! comnwnd
words {()C\'I' l ·OC\V:i). These registers select access to int.f!rn;1I controlk-r
rcgist.ns and control the run-time nspects of the int.ernipt controller.

Interrupt fll!ask H.egister iIMH.I - The Ltv1H selectively enah!es and disables
the interrupt controller's interrupt input. lines. ln tbis manual. lMH refors to
the phvsical register and OC\'V l refers to the 011mnand to read or write th•"
interrupt mask registt't.

Interrupt. llequcs1. Register 0 ftHI · Fol.lowing a CPlJ interrupt acknowledge.
each bit in the IRH refk•cts the state of the corresponding interrupt input.
Tn-Servke Hcgister ilSfll - The lSU regbtPr indic<1tcs tlie interrupt input
lines that the CPU is curnmt.ly servidng.
Poll data · The poli data indicates whether imy enahlE'd interrupt inpllts are
active. If any en11hled interrupt inputs Me aetivP. it also contains the interrupt input. numlx~r tif the hig·hest priority input requesting servin'.

Alt.hough the 825.~)A interrupt r:ontrol!er has many registers, it has only two
inputioutµut II.'01 ports. Table ;3.z shows the master ;rnd sin'"' [i() p<:•rt ad·
dresses . Table ;3.3 shows the registers and the r<·quirernent.s to au:es~ thern,

Puri

Slnv"'

0020H

OOAtHl

0021H

OOA 1 H

Interrupt Con t.r<Jlier!' · Hardware Otlscription

:~ - :~

R.'\V

Port

Access Method

IC\Y.!

Vi/hen bit 4 of the '\'<ilue writt. en to port 0 equab l,
lC\VI is se!Pcted.

IC\V2

Must lx' the next byte written after IC\Vl,

lC\.V:1

The interrupt c<mt.rolJ('r e.>;pecU; ICW:.l
bit 1 equals J If written, !C\V3 m.ust be
bylI· written :ifter !C\\'2.

H \V4

1.\'

The i1lt(•rrupt e<mtrolkr f;xpects iC\V 4 only If JC\V l,
bit 0 e11twls L If !CW4 is written and !CW:~ Is nnt,
lCW·l 1)11;st bl· the next hvte written after IC\Y2 lf
rcvv;; und ICW4 are written. ICW4 must he th•·
next bvt.e written ntter IC'\.'17:J.

Ri\V

ur writ.in~· OCWl req1iires only th;it the inpro•:cs< lie compJi,f,~ Headii;g or writh;g
(JC\V! nc<>esses the interrupt mask registet'.

V\t

0('.Vv2

OCYV'.:'. rcqnirB'i that tll.e initializatfon
t·.% be nm1pkote :ind

OCV\/J

ISH

OCVV2 hit:; 4<J are equal

\Vritinir C>C\'\:;3 require« that the iuitializ.ation pm•"
css bE- ·
bit :] t'<.tt.l nJs 1 ,

if !CVVJ,

()('\'\1:3 bit 4

0, an<l OCVF'.l

Ikadinr; the IHH is a two .~ti:p pnwess. f'ir'it, i,:;stk
the n:ad IHH crmnnand ~write OC\V;~ with oc:vva
bit l equal'; I and OC\V:I bit 0 equals GI Then. reird
the I RR through port 0, Until anotlwr command is
writ.tui ro OC\'\'~'L
reads ot port. 0 :-etu.rn
the lHJt

U1" JSR is a two-step process. First:. issm~
!SH comnwnd lwrite OCW.1 with Ot".V:}
bit l equal-, l ~md 0("\.\':J bit 0
Ji. Then. read
the lSH.
0. Oneil another cnnm1and is

sub!>cquent read.<> c>i port 0 return
Pol! Ll:it8

l{cading the puH r1at.3 h; t.'i. tv.-·o- 1teµ pn><:ess. FirsL
i<;.sue Uw rem! pl}!\ clilUi cnnurnmd !write OC.\V;O. wlth
OC\V3 bit ~
11. Then, read tbE· poll data
port 0. Tht> t1CVV8 pqll rxm1mm1d must
1

~jf:

'.1- 4

·Nritt,cn prior ro

Interrupt ControHcrs - Hardware D~·o;;eJ'ipti•m

d_1(•

dat.a

Initialization Conunand Words
Th<' R2fi!JA interrupt 1'.'<mtroilcrs do not have u !wrdwnre rt>set. After power is
applied to the system and until they ;in' initialized, the interrupt controllers are
in iln nn<lcfined stahL The VAXmnte startup cude initializes the interrnpt
nmt:roll1'rs.

initi<d.izing the 8:2:iD/1. int.errnpt; controller requires frnm two to fou1· initfoliw-

tion comnwnd words written in ;;cquenr'(\
'The intf.:rrupt C•.mtn.illcr
ICWJ. <ls the stmt of tm initialization se·
querH;e. An IC\\'1 reset~ the interrupt controller as follows.

Th"~ trig:ger

mork i~ deared to edge·triggernd mode and tlte edge sense
circuit is reset. After ini!ializntion, an interrupt request input rnust make
a lnw-tn-hig-h transition to w·iwrate an interrupt.

'.L

/\.H bits in tlw Hvl H arc •·k;iro:'d lenilbledl, l:lenmse tlin initialization •mquence enables interrupt i11puts, nn completion of the initialization SP·
quPr\<.'.C. !he interrupt controllers can irmnerliately issue interrnpt
requests. Therefore. the interrupt vector.., and hand.leis !-lhould be initialized prior to illiti:ili.z.ing thP ir1terrupt controllers

:l,

The !R<F input is assigned priority , .

Tlw sb.'\T mode addn'ss is set

[),

lf IC\\' l hit U equals 0. al.I bi.ts in lC\V4 are den red \01

ln the OC\V'.5 rcg;istcr. !.he special mask niode is dr:.Hed idisab!edl and
•,t,at 11c; read bits arc st•t t.o read the I llH.

The interrupt contn!ller en tel"• fully rwsted mode. All t•ther modes of op·
erati\in ilrc vari;1tion1. of t.his 1nnck. Jn fully JV'Ried mode. th1: interrnpr
illput'l have a fixed order nf df'<.TCasing priority and thF priority uf ;rn
input corresponds tn its input nurnher 0 lhig;liest.1 - 7 Unwe~n VVhile the
C!'l i is sr,1-vicing nn inte1 rupt !until the interrupt connolkr recl"iv1>s an
end of-interrupt comnHmd). the controller inhibits interrupts o! uqnal or
lower priority, HOVl'!'VCr. the current interrupt s1,rvice n.m lm rwsted in
favor of a big-her priDritv interrupt as fnll<Jws·

t1..l

The higher priorirv interrnpt input must he urmrnsked 1•.·nahl!'dl.
fhe Cl'\) I.NTH input must bt; enabled fSTI lnstructionl.

NOTE
The 82fifli\ interrupt cnntro!!er is compatlhle with twn
microprocessor fan1i!.ies. 8080:'80Hr. and 8088/li08H:80~~.tW.
Because the VAXnwtc Cf'\! is ;'.ul 80:!81.i. thi~ rnamtai describes
only the 80:Z8i.l app!i('ation. Those bit« dcdil'iited to the SOHO/
808;'1 lamilv are unused ;md d•~scribed onlv as belonging tu the
80H01808[i hmily.
lntcrrnpt Contrull!c!.rs - HardwaN; Desr.riptitrn

;3 ~ fi

The 82oHA interrupt controller hus t.he .following rnu.tmdly t:xdusin; methods of
indknting wheth0r an inh!rrupt nmtrn!le1 is B nrn<>t~·r or n :<lavP:
• The ini(iHliwtion :·wquence selects nonhuffon·d mode in
IC\VcL in nonbnffered mode. 2 lmrdware cf.lnnection to Uw
SPtEN nin dctenninf'S v~·bether dH-· contn)Htr
a rn~{~tc.r
or a sla•:'e. h this mod;;, a high level ;1t dw SPiEN oin
indic;:ites u nwsi:er and n low level at the SPIEN pin. indl·
rate;; '-' slave. The VAXnrntc \Vtorkswtinn use<. this method.
•

The inltialization
hutf<.:red stave in

3 .. ll

Intenupl Controlliws

Httrdwnrc De~cr!pthm

Initialization Command \Vord l ((}020HIOOAOH)
7

Bit

R:'W Desrription

Alwilys 0 !These bits are used only hy the 808018085 CPU family-!

Alwavs J

For \:alum; written to port 0, this bit distinguishes an ICWJ frnm
operational comnu1nd words i and 3. For additional information,
sec Table :1<L
\V

THimrnH MODE
0 °~ Edge-triggen:d mode
! "'' Level-triggered mode

For either trigger mnde. a low·to·high transition at an interrupt.
input generates an interrupt request. In edg<>·triggered mode, to
generate another interru11t request at the snme input the input
must change frorn high to low and bach to high. In level-triggered
mode. while that interrupt input remains high. the cont.roller can
generate additional interrupt r<:quests for that input. The
VAXmvte st<Jrtup cnde initializes the interrupt contrnllers to edgr-.
uig:gcrPd mnde.

w
\\:

Always 0 iThis bit is used only by the 8080/8085 CPO fomi.ly.1

8INOLE,CASCAIH:
n "''

Casc:1dc rnmfo

1 .c:c

Single mode:

Single mode indicates that this is the only interrupt. mntrn!ler in
the svstem. 'fherdon:. it is neither a master nor a slave and ICY\':~
is noi~ written. Cascade mode indicates that them is more than one
interrupt cont.roller ln the system. Therefore, it is either a mac;ter
or a slave and l.CW.3 i8 required. The VAXmate \\•orkst.ation uses
rnsc;:l.de mode.
IC\.V4 R.E(--}Uf;s'f

0 '"
I -"'

IC'\tV4 ls not required
IC\-\'4 i:<: required

This bit indicates whether IC\V4 is wquiri?d in the initializ.atiim scqutmcc The V1\Xmat•' workstation requireti IC\·V4.

For Uw muster lC\V .l and lhe slave iCW !, mm 1 Hf.
Interrupt Contrn!l.1~rs · Hardwi:mi Description

:5 - 7

Initialization Command \Vord 2 (0021H/OOAJ HJ
6

T6 ,-~~
Hit

Ri\V

lT4 r,~, J. . 0-_L~ ~r OJ
4

Description

Bib 7-:~ uf the interrupt number for interrupt input !l
This vBiue corresponds 10 the nddress of tbt• .inrerrupt V<'Ctnr di·
vided by four. The interrupt controller gencratt~s a sequential inter·
nipt number for each of the interrupt inputs by ORing tllP
int.ermpt input numb<)r and l('tV2. Because the int.errupt
number is ORed to the Y<Jlu!: in JCVV2 there is no carrv involved.
Therefore, the vahw in IC\\'2 must he
.
<livi~iblt> hy 8
{modulo H.1.
·
?.-0

For the mDstcr lC\V;( us;o 08H. Fnr the slave lC\V:!, use ·,'OIL

Initialization Command Word 3 (0021 H/OOAl H)
\IVhen there are two or more interrupt controllers in the system, im IC\'V3 is
used in the initializlltinn sequence. The VAXr.nate workstation has two interrupt.
controllers and requlnis lCW:!. The meaning and use of ICW:l depends on
whether the interrupt controller is a master or a slave.

ICW3 (Master)
0

Hit

RIW Desrription

7-0

\\'

For each ma.~ter interrupt input that is connected to n slave. the
corresponding ICW3 bit is set. LI). The master interrupt controller
can then determine which interrupt inpnts require a slave ident:!fication on the rnsrnde lines. For the master ICW3. use 04H

ICW3 (Slave)
7

l
Sl.AVE

0
- ···~·L .... --

Bit

Rl\V Description

Always 0
2-0

S LA.VE ID - Shive hfontifkation
The slave identification is the muster· interrnpt input l'i-Ol to which
the sl;ive is r:onnect.cd. During the CPU inLPrrupt acknowl.edge sequence. the slave <:nmpare'l its casrade input to the~w bit;s. If they
;ire equal. the slave plnces the interrupt vector number on the f.i(l
data bus. For the slave JCVV3, use 02H.

1.ntcrrupt Controllers - BHrdwHre fJpscdpUon

1\)ways 0

SPEClAL FULLY Nr,:STED MODE "
Di>«ib\e spw:ial·fully·nested mode
/: =~ Enable spcd;:ii.fu!ly·ncsted mode

0 "\V

BUFFERED l\H)OE and. fd.ASTER/Sl.AVF
OX = NonhuHere<l mo{k ·· in nonbutfered mode. [-!. hardware eon·
neetinn to the SP/EN pin determine"> whether thCT control·
lcr is a master or u i:ilav;c <ind bit. 2, the master/slave
sclectmn. h;is no etfo<'t. In thi» moifo. a
level at the
SP!EN pill iudk:ates a rnaster and ;i low lend at th•' SP/
EN pin indicates <J slave. Tlw VAXtnate workstaJion nses
this rnnd<'?.
1n
Bui h·red rnodr~ slave · Th(• VAXnwte 'vorkst,citlon i'.l
bl•" nf operating in this nmde
' '
Buffered nwdc ma.~tcr The V ''\Xrnate workstation i& inninf OJ)erat:lng ir~ ~.hi~ u1J.1d(~.

r:or l\lODE '
(! .::

l\.fodc

NorrnaJ EfH

In this nJrKh.~~ the C·Pl..! rrn~st \vrite an F.CH

c(HnnuH:1d to tht} lnt1~1-rupt controHer. 'T.h(:i. \/A)(ntf..ite
code initialize;,; the
•'OHt.rolJ,;r to n<Jnn:>l. f.0.!

Thr· EO! C•nmnand is

in the

r:o•Tmrnnd

,. vurd ~~ descripr.ion,
/\ub)n1B.d.c ECJI ·· In auton14tic E{)f xnrahi.., the int.t~rn..1ot- cnn-tro!ler gfn(·i :jtc.s its (J"Wn Et)l on the -seconrt

CPU JVIOfJE
8ll80i80gf, rnicrnprocessor
I =- 8088!80);<G/HOL!81J microprnc•~ssor fomily

n =

'Tl;(· V:\Xrnnte v.-·orkstvtlon. u~es the 80~~Hn CPl.I 111od.e.
mndP is for master interrupt •.·ontrotler~. For tho
n1astf::r interrupt contrnHer. f'<l("h sl}n'e controU.er Ls a
Thus, the mast.er coni rotler cannot. r050/l.'te t.he

int+:tTUJ.H:
oi the ;;lave

t.'ontrr1He:r ~nterru.ot ~nputs" f.f n s1ave controHcr h~~ dH act.i\'Ec lnv~!tv
thn.t is nested in favor c'Jf J higher pdorit.y
the ne·'/.,.-· sh-ri..-·e intF:rrupt rf~qot~.st. ~rhi~

nesting of slave interrupts, In sped.al-fulJy,nested mode, the master inter·
rupt controller acts on all slave interrupt requests, which allows the slave
to nest interrupts. The VAXmate workstation start\1p code disables the
spudal-fuUy ..nested mode.
Fur the ma«ter 1CVV4 and the slave ICW4, use OJH.

Operation Command Words
The Interrupt controller provides three operation command words 0 -:3) that are
programmed after the initialix.ation seqUtmce is complete. The operation <::ommand words select various rnrnfos or operations as follows·
•
"
"
•
"
•
•
,.

Read or v;rrite the interrupt mask register
,\ccept specific or nonspecific end-of-interrupt commands
E:nable or dis!lblc various automatic priority rot.ation schemes
Set a specific priority level
8et or re.set the special mask
Read poll data
Read the interrupt request register
Read the in-service register

Operation Command Word 1 (0021H/OOA1H)
7

MASK BITS

Bit

Ri1W Oescriptfon

H.1

RiW Interrupt nw'>k registtir bits
0 ~ Corresponding interrupt inputs are unmasked !enabled)
J '~ CorrespQnding interrupt. inputs an; maskt-'!l (disabled)

OC\Vl mads rn· writes the interrupt mask register (IMRJ. Each bit in the [MR
enables or disables the corresponding intern1pt input.

Interntpt. Controllers · Hardware Description

3- 11

Operation Command \\lord 2 W020H/OOAOEJ)
7

ROTATE

EOI

()

----T- -·---.-0

INTERRUPT LEVEL

- _______ _l ______

HOT4.TE18VEO!
000
[Jisab!t: P)t.ation in aut..on1atic ['~t)I n1o(le

nn1

N'onsperifif•

(~ 10

No operation
Sper'il.ic end-ol-intcrrnpc
Enable priority roi.atl.nn in ;Jl.ltomatic EOI mode
Rolette
on
fi;() I

I) 11

lOll

101 t I0
J 11

Rc~tale

qF;f)l}

t(1

Hqt:Jtc priorit:.v (H1

·i

\-V

H
F\_:;r valu(~s vl'Titten tc1

'}
•,~

/\lwavs 0
This .bit

2-0

Vii

INTEHHUPT LEVEL

rna.nd "'~·ords 2: .Etnd :_-}

ror
irmut

are ignx;red.
{)CV\'~2

iss11es an end~of-.irtt.ertnpt \:onnnand
:art~ rv}n-~~pecii:ic. r.rht:}" act n:n th{:~

Sorne ()('.\V2

has rhc highesr priority, whkhr,~ver •J!Hc that nwy be.i

do not use lNTEFtJUJi-'T LEVEL •OC\\2 bit;; :'.-CH.
the intenupt inpur number \il-71 in INTERRUPT LEVE:L
For the master OCW2 and the sl'l.VE' oc:w2. USP 201-l
coinmandl.

EOl

Priority Rotation
In nonspcdfir or automatk EOl mode. priority·· rotation has the effi>ct of
assigning equal priorities to all interrupt inputs. On receipt of an I•:(H cornmand. the interrupt controll.er assmnes that the active interrupt input with the
highest pdurity is the interrupt just completed. The priority bits arc rotated
until. the just compll-'ted interrupt has the lowest priority 171. If thnt interrupt
input. requires further service ..it must wa.it until it is again the highest priority
interrupt or until all interrupts of higher priority arc inartiY«'

In Figure 3-l interrupt input;; 2. 5. nnd 13 are requesting s•:rvice and interrupt
input 2 has a higher priority than interrupt. inputs f> und 11. After interrupt
input 2 is serviced, the interrupt controller rotates the priority Ml shown in
Figure B<'.. In Figuro B·2. interrupt input :3 has the highe,5t priority, but it is
inactive. Because interrupt input 5 has the highest priority of the~ active intm"
rupts. it is the next interrupt input serviced.
Rotating priorities to a specific interrupt input is nnnthcr met.hod nf priority
rotation. In this method, the lowest priority is set. thereby fixing all other
priorities. For example, if interrupt input :~ is progrnmrned as the lowest priority, then interrupt in µut ~ becomes the hig;hest. OCW'.~ bits 2-0 define tlw interrnpt input number that is ussigned t.he lowest priority· This method ls not
used in the VAXmatc workstation startup code,

Interrupt Controllers · Hardware Description

".>

0
-···~

,-~

j
0

0
----~~--

Operation Command Word 3 (0020HIOOAOH)

Bl!

R1\.Y De;>cription
\\/

F'.NABLE SPECIAL MASK MODE/SPECIAL MASK l\10DF
00 --No ae1_fon
No ;,iction
01
HI
maf;k mo<l1;
Disable
Enabie
11
mask mude

Sonic operations require that an interrupt s1,;rvke routine dynmni·
caHy cbange the priority structm-c. Masking an interrupt input in
the speciol mask inhibits that pr.iori.ty level and enables 111l other
priority levels Hower nnrl higher) that are unmasked. After tmilbling
;mecial mask mod1e. rb.e socd;;l mask is re;-1d or writ.ten tn the
l fv1 R.
.
/\]ways 0
For vnlues writ.ten to port l.L this bit disting-uishes operational {''Jm·

rnanrl wnrds 2 tmd a from an IC\.V L Se<:' Tahle 3-3.

:;,

Alwan> l

This ·bit di.st.lnguishcs (H ·w3 from OCW2. Se1.' Table :Vi.
2·0

POLl..iH.t~/\D !R HEGiHEAD l.5 HEG
000 coo No Hctinn
001 == No act.ion
{) J (I
Reod the !RR *
0l J
Head the lSH. *
I 00
RPBd the poll tiAta **
lO
Heid the poll dai.a. **
11 0 c:. Re;id the poll tfafa. **
111
Head the poll uata. '"'

s,,.,, T;1blc ;).:J and the iHRilSl1 description,
SPe Table :3<3 and the poll comnumd description.

Fm st;mdard operation of t.ht: VAXnwte workst;1tion, neither the master nor

the slave use OC\Y:l.

lutcrnqn. C{lntrol!ers

Hurdwnre lkscdption

Interrupt Request and In-Service Registers
Interrupt R<>quest Register

In-Service Register
l

r·

- - --- -··1

L__

6_·-· -~·

r__s__1_--·-"·- :r_.s___

______r__s_'_5 __L

1 S4

ThP Interrupt Request Hegist.er i!HHI and t!w In-Service H.egistn (ff>rO main·
tain the st.;ite of the interrupt conrroller. During the fir.st intE:rrupt acknowledge
of the CPU interrupt adrnmvlcdge sequence. the I flR latches t.hc, state nf the
int.enupt input. lineR. The internal output of the Int1·rrupt. Mask Hf:gi.ster Ol\1HI
gates the output of the J RH to the
Pllcod.er.
that one m
llWre JHH bit~ nm ~et 1active1 and
\enablt,d\. tlw priority encoder de
tnmiiws 'Shieh one has the hig·hest
During the second Interrupt acknow.ledg·P. that !RH. bit ts strobed into the C(J!T('Sponding [Sf{ bit, the edge
;,ense circuiny !or that intPrrupt
i" ne;:;et, and tlvo interrupt vect~n
number is
on the I:O dat;-J bus.
Because: tlw interrupt controlfor can nest. iutf·rrupb. Lhe ISH <:Bn cnntetin one .
r\Yf), or In(_'•te bits that are ~et- 'fhj:-; shf.nvs tJl~!t. another interrupt tv;JS lH~knrY~":Jbefnre other intFrrupt
was comp.leted. A specific end-uf-

lntcrrupt iEU!i cinars the indkated ISH bit. A. n<mspecific EOI deurs t.lie
.lSH hit,
lf an IRH bit i;:; set i;wt.h·e\ and m:.J'iked Ulisabiedf, umn<Jsking {Nioblingi that
active I.HR bit creates an int•:rrupt

;J.

lnlerrupt Coutrotlers · lfardwm'(• Description

Poll Command
WJwn issued. the poll command performs steps siinifor to those described in
the HUV!SR description. The poll cnmmand rcplnce:<i the function of t.he CPV
interrupt acknowledge seq1ience lmitead of placing the interrupt vector number
nn the VO <fat<.i bus, the pol! con:urwnd connects the output of the poll data
register to the port 0 output buffer. The polling interrupt handler then reads
th~' poll dat;1. to determine i! an interrupt input. is activ« and. ii so. which one.
Tn complete t!w int:ern1p1· seq1ienu~. the polling interrupt handler must issue an

I·XH.

Poll Datu Register
1

INTERRUPT lNPlIT
NUMBER

Bit

Description

INT 1\CTiVE FLAU - lnterrnpt <Jctive ft11g
= No a<.t.ive interrupt inputs
J ·"" At le;;st one interrupt input is active

2-0

INTERHUPT INPUT NUMBE.ll

if hit 7 eq11al'::l i _ these bits contain the intPrrupt input number II}
7i of the highest priority interrupt input that is act.Ive. If bit 7
equals 0. these bits have no meaning.

inforn1p1 Controller"< - Hiwdware D\!Script.ion

Interrupt Sequence
The followlHg· li!it descrihes i.ntorrupt
Each ltfln in tlw list de<;aiiws
a sysl'crn st:-•t.f' or event, .Alter <'> discussion of the 13rnw or f•vent. tlw
tion indicate;: tho next state or ev,mt, For th>' folluwi.ng interrupt processing
description, it. is assumed that the interrupt ront1.·n!lers am initialized i.i'' pr"·
virnJs!y de;icribcd Lil.tee Figum :s-3 shows tht\ same
in the form of a fh.1w
chart.
l,

tJntH tJnc nr rnore. int~~rrupt. <xn1tr·0Ber input l.ines hec{_nn0 <::tctlvei the con,

tn:iiler is idle. If oni..~ or rn.nre inptit~ n.re active . go to 2,

H 'Jri· nf t.h,, !W'~·lv ·wti"f'
clth;·~\vi~c-. ~u t-~; ;J, ~ ., ' ~
:~.

H nther intm.·rupt inputs are p<m<lin.c:. go to f,, Otlwrwi.se. gn to 1.

H no other interrnpt input<; are

fl.

ff the «rmtro!k·r is
g-o tn 7

()ther~~vise~

ti.

If iJny intr,rrupt has a priority
tlw CPU. n1•s:-. tho internipl.s

1'he conx.rnik -r netivntes its Lntcrrnpt output lirH:- :1ud vn.:ti.t-~ for dn ac1

frnm the CPU.
lt the int0rrupt nmtroHe.r input. is a slave input. i.het1 the slave
output. line a•.:r.ivates the master interrupt controller !IlQ2 interrupt
The master interrupt process ,;;tarts flt •;tep 2. Evenrua!!y. the
mdster I
innut beromes the highest. nrinritv master [ntenur.it that i.s
l:Ktive and
~:aster contrdler or.nn'S ~t rhis,:;h'n. /\t, that tit;)e. both
cnntrn!!ers are walling for tlh~ CPU

in either case. the 1nast:er i1Jterrupt. contro.Her fH'.th·ab.}~ its int!~JTU.pt
ontput line, v.rhid1
an exu,rnal latch. The extern:;d latch dn\.'{''l
the. CPU lNTH input.

NOTE
Th.ls external. !atdL br;tween the master inr.errnµt Ct>nt.rn!Jer in,
t.errnpt output and the CPO INTR inpuL was
dw~
to an advisnry nn an 802!-\fl CPU
ffow.
Hisabi.ing the CPU JNTH input b+;forc dis;;bling an int.•Jrrupt
controller
or lnitiaiizing the interrupt controliers c:an k;a1:~'
the !atth st;t. Oa
the CPU !NTH input. the lat.di
•:~ould indic.ate an inLerrupt rt"r~\tH~st 'Ahen. none exi;.;ts,

To avoid tbis slluat!on. disi;1hle the interT11pt controller input or
wri.te the first mast1'r interrupt 1·ontro\lt}t iniii,1liz~11·.ion r:ominand
before
tile CPU INTR input

lf the CPU .!NTH. input; is disablt:d, rhe interrupt r·ontroller continues to
•va.it. If other intt~rrupt controller inputs become af'.t.ivt:~ during this
pel'iod. go tn 2. \Vhen tht' ('.Pl! IN1Tt inµnt is enabled. the CPU recog·
nizes the interrupt request and responds with mi flduwwledge sigrn1L
the admow!edge. the interrupt controller sds the highest.
the in-service register imd re<:wts the con·esp<inding bit in
interrupt request. register This al!rJws the controller to n:cognize annt:hcr int.t'rrupt reque~'t fit that internipt nmtroller input.
·
'rhe CPU issues a second acknowledge signaL \'I/hen the master interrupt
controller n'cognizes tbe se\:ond acknowk'dge signal. it determines
whether the lnt.errupt. input source is a slave interrupt cuntrolleL lf the
interrupt input source is not a slave. the master controller placell <:1.
preprngrnmmed 8·hit interrupt, vector on the inputioutput H!Ol data bns.
If the interrupt input source is a sl:we, the master controlfer places th;;
shivt· addrHss !ma<;ter interrupt. input. number 0-71 un the casrnde lines.
\Vhen erwb.!cd bv tile slave address on the 1:ascade lines. tl11c' slave phicell
tl'w preprog:ramrncd 8-bit int.errnpt v0ciur 11n tlm input/output II.IOI duta
bus. In either case. tht· CPU reads the B·bit interrupt vector. stacks t.hi;
cmnmt state and lwg·ins executing the interrupl handler that is pointed
to by the contents of the interrupt vc(:t.ot'.
;;.

The inh·rrnpt coni:roHer!s) are waiting for ;m end-of-interrupt !EOO com·
mand. VVhcn t1 sliJve intPrruµt is proc<~ssed, an EOJ comrmmd is required
by both the slave and the ml:lstt>r

If an intcrrnpt twcurs during this waiting period, go to step 2. When th1°
CPU writes the end·of·intrrrupt <:1)mmand, gu to -;t.cp L

Interrupt Controllers · Hardware Descrlpifou

;

4
'

l i

i I

j j
i,.~ - ~ -- - -~~-~~

Interrupt Controllers · Hnnhrfll«'

Programming Examph~
The following programming examples demonstratP:

Initializing a master or slave 82MlA peripheral interrupt control.ler iPIC)
Prog:rnmming the PH: interrupt nrnsk register
Issuing end-of.interrupt rommands to a master or slave PJC

The example provides routines as described in the following::

pk_init

Initializes the master and sbve PICs.

imask

Masks or 1.mmasks tbe specified bit in the interrupt mask
register.

eni

lss\1e5 tu1 end-of-interrupt <;(llmnand to t lw ;;ppruprialc Pl Cs.
CAUTION
Improper progrf:lrnming or improper operation of this device can
cause the \'AXmate workstntinn to malfunction. The scnpe nf
the programming example is lin1ited to tlw context provldt!d in
this manual. No other vsc is intended,

Interrupt Con1.rnlfors · Programming Example

Constant Values and Data Structures
'fhe c•:jn:-:etarrt. ~..:;:lltH.~ /\lPlC' rh:;·fine:.s the nurnber of
hJ t-he \_.-,A_Xrn;:d:.e \-~.:cn-k!:;:ta.tion.

in t.errupt con troJk~rs

('O!ldibon

ports of tln~ 8:25~lA peri_ph€-.r.,_;l
n•ntr0Uf·r 1PJCl. 'rl18c·>f! two port« a\'<'.e~s tlw PIC
Tbe hit

'The ~;:~t.r1Jcttn(: f·_ynf: Pl(' z.k:fines the

1'!!.€: struct.-iJ~-e typ('.; .Plt-·

T' de.tines the typ~~ nt d~~ta

P!f\

J nit.iaHzation Data
rr-be ;zrr~JY (1f strtH~t:ure:c<
rlH:. actusl. d.nta for .ini.tiBlizi.ng tlw
n·iastt:T ac.d _.-;[u;,-·(~ Pt(~s Later rerereneea to the PIC numher refor to the pnsi·

•l

/"' de:fi.ne constant·E< and atruct.urea used in 5259 PJC example

!"' numlrnr of pies in ay.et.em •/

#defin" NP.tc
ldefine EDI Ox20

/* bit value of E.OI convnand *-/
/• define pie I/D structure •/

1'Jped<>f AtxU<:: l;
{

,h when address line AO
/l• when address line AO

unsigt1li!d char portO;
u.nsign"'d d:ia:r port t;

()

or/
oi-·./

} PIC:
typedef s"t:r:uct
{

I+ base l/O address

or pie t/
. '
'!<{

/* ir baa a •lave ar elave i4 •I
!• icw4 mode data */

.::11at· icw'l;

d1wr icw4:
} PIC_tlAT;

PIC DA! ellptcs[~PIC]

:~ de~ic~

datA tables */

{

{P IC ') Dx(l(J'.ZO, Ox08, ();<1_14, OxOl }
(1;,.,.r.
~ )Qy:OOaO, t)x70. Ox02 1 (l x:() 1 }.
l L'vi
};

/# pi~ 0
1~

i~ the master
*/
pie 1 is the s}ave

Initializing the Peripheral Interrupt Controller
initializf,S the mastt•r nnd s!.ave PICs. neeml'>" the HOM
BIOS storhip sequf'nce initializes the pcriph;~ral intnrnpt c;mt.rn!lers 1PIC>, i.n·

TtH! fmwtion pi,,

it.inHzation o{ th.F PJC:s is n(Jt norrnnJiy rcquirt.:tL

Because r.hc init:i:1lin1tinn 5equence deiirs the interrupt mask registeL tlw CPU
!nJ,E:rTupt. fli1g i.s cl.eared after the iniOnlizatiou js st.nrc~d ond before the IniUt:di~
2atit:.n1 (;o;! cnm.ptele. Thur~. no
are p(~ttding- \Vht"n tbP initializ.aUon i;;

started and t.h~~ <_:-pt_i ViiB not respnnd to any inr.ertuµts that l:.H:.con1e :tctlvc
th0. in~riali;:.ation -~Pqucn.cf:.

The tin;( t>\•o instrucrions write J vaine to pon !) of t.!1e imfo'ated PIC. The
·va!uc (1f f)it 4 is
b:y this O_pPrahurL \VrH
(i Vet.iue to port n_ \-Vith bit- 4 !::eL
seh~<:t.'q the f.(·\.-'i/'1
and indiJ:ates a rt:set st:quencc 1'he Pl(".: stores the·
IC\N .1 bits in rhe lCi.V J
whki1 <;W.rt>l dm initiali;wtion

Hit l is dem· indir;1tinir thnr. the addres<:pd FlC j,, irn·nlvr:d in ii <'n.«ni.de
Hnasto/,'iLH'! c•!'tanu;en·;~;nt and that lCWJ must he '>>rltten durin;..:- thr: \nitiaii?:at.Icn1_ ser1uc:n(·t: T'h~~t ~s, thfl PlC- ; 1~ not
in a st~1~1.dft.lone
t~1rvir(HH~1cnt.

AH oth,;r lCVi/I bit!.
used.

~rhe

third !:-tstnu:t)on \\.T!tes thE has(· interrupt:. vector t-n port 1, HP(:<sus(~
the sc:cund \'d10_e. v.triU-,e;:i, in. 1.be f,\~qu.t:ncr:::i the PI(~ rnutc:-; rhe

~hjs i~

vL-tiu~'; to

1cvr:?..

rupr.
jnt-.errupt yertur r~uJ11bf~r.

mo(hi.o 8.
•:L

'fhe -fuurth irrntruction iH
upiJH vvhi:.;thPt t.he P!C i~ a nv~.sr1ir oz
a s.h.1.\rf'. Bccau;9t: this .is the third \'rtittt~ \\Tltten in rht: ~~('quenre ;,nHi
1(~\V J iadicatr:d u ca.sr_:ad.t; n1c1de. ~.ht:; PIC :.·out(:s tbc i.,·3.iue t/J lf.:.\/'!&"'~1.

If t.lw P!C is 11 master. each bit '\Ct in tho value indicates that the
correspon1Jing interrupt input is 1·onn('rted to n slave PIC. F'or the
VAXmare. only bit 2 is sPt.

H the PIC is a si3YC . the value is the slave identification. The slLn:e
idcnlitication is a nilue between 0 and 7 inclusive. imd correspond~ t.o
the master interrnpt input tn which it is cunnected.

pie initO

injtial.ize mastPr and slave pies

•10id pie ini t 0
{

I* initialize all pies •
/• variable tor loop cautral ~/
/' to hold GPU Jf st,,toe ·"/
/* pointer to PIC data
1~ pointer PJC J/O structure '/

int :L;

:!nt int.r flg;
regiater PIC_DAT •ppd,
register PIG *·pps:

trntp(al1pinl[O) .base, OdO;

outp(allp1cs[1J bnae, Oxl1);
lntr_flK s int_nff();

/-1 write olave

for(i · 0,

write master JCWl. i.a cascade

1CW1 in cascade ~I
/-' turn CPU interrupt!'! off

NPlC; .H+)

{

ppd

&allpicafi];

pp;

ppd· >base;

outp(kppe·>portl, ppd >1cw2);
outp(kppe·>portl, ppd··~ic~3);
outp(&ppa->pnrtl, ppd->icw4);
outp(&ppe->portl, Oxff);

I• assign pointer to PIC data ~/
i" irnsign pciinter t;> I/O porta "/
/+ v.:ritr. 1CW2 ",f-/

/.;.. writ€ lCi./3
/ ,~; •rr.ite ICW4
~iaak

all interrupts

}

!• turn CPU interrupts on •/

1nt_nn(intr_flg);
}

'I'he fifth instruction \vritP~ the lC:'\-V4 value tff po?t t

•

Bit, O determines the rnicroprocessor family. !n t.his case it is set and
indicatt·s Uw 8U8fi/8028fl rnode.

•

Bit l is clear, indicating that tlw intnrupt handling rout.i1w is<;ues an
end .. of-interrupt r:urnrnand aftPr the int,enupt is processed.

•

Bits 2 and 3 am cl•:'nr inciicating the nnnboffen:d mode of nperntion.
Fnr tht., VAX mate. a perrnnnent. hardware 1:onnection detern;ines the
rnaster/s!avt• relHtinnsh·}p.

Bit ,1 is dt:ilL indicufing- thot the P!C ls not in spndal-fuHy- nested
niode.
.
•

All ntlwr bite; am not u<;erl ond art' de11r
IuternqJt Cont.roller.<; - Programming Exump!e

~fr:t:d

;·i:__ :

bir. :_.i1:_:_r: ~:-; :-~ts.
l)!:(' •->~J!.~Un_:~~.:..~

ict.:~trnp~:::~ ;.·1:_·z.~ }:.H.~~-iOFJ:g-. '.iH>

•..s,,bich Plf" i~~~-:.J<::d Lh~:· ~~-tt.f·~'r-t:(•t . .ff t:~: inter·n_q.:{ :i:J
bu) ~i.~~:\:~: F!t'\ d.!·; L.~Ci1 itP1::::t 'r;e L~;~~:..t(,::·d (<> t.h•:,: ;:;.L:::•Ji_: ;:u:rj th~;t~ ~.c U;(~

~:u;~n).JO£•t_·t:_:~· i_;~d~fiitf·'.7;

~s~stL::;d

to
F'cr

!-1';:;:-; ;gtx~~·:-HD!:"· p;~~)-'\---:-.-~ fr)~.
ch~.;::::~s

tiE:: ('·-FU ~:FJtPi~lBth:J:lih~ f;t~-H~f.:::;; ~t~ Ct!~-~·1::~::·;~: ,::;ta:·.c· n~·~d

::r_t1ll~~

B;:·c~.P-~~;(': nc-n~_: of thf; :1::~_'!.: ;,- :_in~ h~~;-id~_{:r.:.., ·~~

/ z. eo.i ()

int

ea ta.bl i sh End- Of - Inten·upt for pie (re•)

f• which pie handled interrupt •I

pie:

{

f* write eoi as indicated •/
was it the slave pie ? ~;

outp{k(aHpicsfpicJ base) >po1t0, !':OJ);
i.f(pic)
outp(~(i.Jlph·s(O) base) >portO, EOl);

J.~

write eoi to master •'

}

imask()

/.<.

nask or unmask deairE'rl. b.i.t in pv-

, bitno: en:<tb1~..:)

1~
/'~

int pi<:;

1nt hitno:
i;it

enab1e;

'1H>flk

registrr

ePt or clear bit in ma~k i/
regi.a~~r of deatred pie
\<ihich pl{~ "?- 1' /
which f>jt 'f
enable or diaab]e ?

{

11nAigncd char c11rrent:
ux:us. ig.ned ch.Ztr fl'.aa.k

ppe

~h~

mas~

~rite

PIG ~pps

r~gister

allpi~o

ru~rent

•

anffign pt)inter tn I/O J)Or1.s ~/
'>. 1·~a<l current ~RP~
/:! get up corre(t bit */
/t ·-Iear the hj_t ~;

base;

inp(Rppa-~por~l);

~ 1 << bitno;
if(enable) cu.r.t:i£nt

~aRk

maek,

l . cur:nrnt) :

}

Con trnller s

Chapter 4
DMA Controller
Overvie\v
The di.ruct-nwmory·acces~ iDMAI controller is an Intel 8237A·fi, programmable.
DMA controller operating nt 4 JV!Hz. The D.MA controller allows the direct
trnnsfer of 8-bit data between DM;\-capable, input/output (I!O; devkes and
memory. The DI'vV\ controller has four. independent DMA du1111wls. Table 4·1
lists the ilssig-nmcnt of the four DMA rc(111est lines. Each dHmnel hvs lG ad·
dress lines and an external 8-bit pag·e register. Thus, each diarme! can transfer
a maximum of 64 .Kbytes any·where in the JG l\Ibyte address nmge.
The follnvving: !ist shows th1; nperntional modes and restrictions of the DMA
cor1troller
Single transfer

This is the sugge<;ted mode of upcrntion.

mock transfer

To prevent interference with lJRAJv1 refresh
limit hlor:k tnmsfors to 8 transfors per block.
T:1 prevent interference with the DRAM refresh
cyde. limit demand transfers to 8 t.rausfr•rs per
dern.and.
i\s bus master . the shwe Dl\JA controller should relic:a>;e the bus aft•»: 10 wi.

timing

Compressed t.irninF: is not supported by the processor
boGrd hardware.

Memnrv-tcH1wmory transft'rs am uot supported by
the prnces.-.;or l:rnrdwan:'.
Extended write

The e:,tended·write
does not pnwide suffident
data setup time Use the nm.·mal lHvlA write

DMA Controller - Hardware Desniption

4- l

Clumnc!

Request Line

Avaiinblc
Av0ilabl<'

IJhkctk Cont.roller
Avaiinbl.f'

Additional Source of Inforn1ation
Intel Corporntiun docm1wnt. prn\idf's ;1dditinn:J! informatior1:

The

Operation
\'>/hen the LilvlJ\ com::rollcr rcceiv''" a DMA n:qm:st from a peripheral d,;vicl',
the DJ\'lA cuntw!ier sends H hold request. sig·nal t1J the CV!..'. \\'lwn t.he CPU
1.·t'sponds with a hokl acknowledp;e signal.. the DMA controller takes •:nntrol nt
the VO cbt.;1 lius. Lhe systern addn:s 11 hus . and the nmtrul bus. The cnntrnHer
then f;<:neratns a UHJlt memory address :ind iwtivates the corresponding DM/\
acknuv·r'led,ff(~

Enc., the I/() read or writf~ line~ 8nd the 1.T1etn(H~} recd or vvdt~-~ iin.r~
the D!\t'\ ad;n(nvicdp;e, the
L'O device transf~:r'< ircad':I
or wrires) tlit> dara on th·~ di1t:i bu:.. Thus. dw data J.;; trnnsf•)ffl:"\
hety;.-·een the lf() d.e~11c.c ~inri n1-r~rriory
On.

t.''yc!e can a.ssnn1e seven., hepatfite :r.1tates, Each ~,.~trite i.s
i::Jock
~rablc 4--:~ de~cribcs rhe v·orit1u~; coritroHet st;-.tte:;

'"rhis !~-- the ina.ct~ve .state. Nn \"alid LHv.1
c:PlJ C$.ti1 p:··ogr1!r:n the lJiv:l/\ cnnt.rolit~r

ol une i'.i!L

rf:.q~u_:st,s gre

the

""''""''"'"'

~1 hokL

01e ntknn·l;1

S\·V

to con~t~I(:tc H t-ran:>;.t"f;r_ \1,/dit st:r:__ (:2~ <-U~
betv. -~.::~c:n S2 ~u_:d S-'.L •Jr s:~ ,::·~nf.:l S..:L

v~:·hen n1orf~ ttn-~e 1~1
_in~crted

Idle Cycle
When none of Uw !!O ch<Jmieis is requesting VMA service. the OMA contrnll•;r
enters the idle
and performs SI states. At each dock cycle in the idle
the DM.A controller samples tlw DJVlA reque.;;t lines and the chip sclPct
If ;1 Dl'vl/\ r<!qm,st licw bw:onws ~wtive. the Ill\iIA controller goes to the adivc
st.ate. ()therwise, if CPU ltas selected the JYl\ll\. contrnller and t.!w CPU has
control ol thr1 bus. i.he CPU can read or write the lll\lA nmtrolJ(,r irHerna.i

registers.

Active Cyde
\\'hen the D!\:lA controHer is in the idle ryde and a nonnwsked channd
requests Dl\·L'\ servic1;, the controller iAsues ri bold request to the CPIJ and
m1ter'i th•2 active
The DMA service will then nccm in one of the fnur
fo!lnwing modes.

Single Transfer Mod<'
The· Dl\'!A controller is programmed to perforrn only one tnrnsler in this mode.
After the trnn;;fcr, the word count is decremented and the address i'l either
decrement<:'d or incremented. \Vben the word coum goes from 000011 hJ
FFFFH, a terminal count iTC1 sigrnil is generated, ~;td will auto-initi1ilizp thP
clwnnel to its origfou1 condition if it hm! been progr;unmed to do so.
The ROM BIOS us<:>s this mode for data transfers hetwei:'n tht~ <li;,kette ':ontrnl
!er and 1nmnory,

Block Transfer .Mode
In this nwde, the DM/\, controller i;; artivmed bv u DMA request tr1 continue
transfers until a TC tword ·~trnnt has re;whed FTFfH} r;r an r:xternol
end·ot·pmcess IEOP.1 signal occurs. If thf; chmwel has been prngn;rnrned for
anw·initlai.ization. tile anto-init.ialization occurs at TC 'JI EOP. This rnode
should be limit<:d to
transfers !assuming no additional wait .>Whosf to pr('vrmt interferPnce with rdresh

Demand Transfer Mode
The DMA controller performs trnnsfers until a TC or exil.,rrrn! EOP occurs, 'ir
until there is no DMA request. Transft>rs mav continue until t.he liO devke lrn~
exhausted its data niparitv. Orwt: the l'O device has urnglit up. llM/1. service 1~
recst11bibhi:d by means ol a D~l/\ req11w,t Trw intt;rrnedi;iH~ \:ilue~ of addre'<s
and word count are stored i.n DM;\ cont.rnller internai rr~gisters hetwe<-m :-.•~rv·

iois while the CPU is running, At the end nf the sr!rvir:e.
an EOI' •'<Jn
cause auto-initialinitioo to occur. Thi.;; 1wide ~hnuld be limited to t:'ig:ht trnn>fors
per dernand tu prevent interference ;.vit.h refresh 1'ycl.es.
DMA. Controller

lfardwiirP De<;criµtinn

4 - '.l

Ca1'\cad<• l\:fode
Thii.• rnnde is used when DMA controllers are CBscaded for system
In this configuration, the initial controller tkt-ermines the priorit.y of the ackHtional contrnHcrn, Each ot the additional controllers estnblish prinritv within
themselYes and make the Lll'\L\ rP<.iuest tn the init.ial controller. The initial con·
troller dues not out.put ;lny address or control sig:nais, slnc1~ they could <.'onnict
;vith t.he outputs of tlw udded coHtrnHer.

Data Transfers
Tlw DMi\ !'.•mt.roller can perforrn mad. write, ur
opnatiorn-i in <?.ach
tran:sfer rnode . .Ftcad tr.1nsfr.::r~ 1nove datn frorn rucrnory to an I/() device: Yt'Tite
transfers move data from an L'iJ device to mmnor.v·: and
trnw;fers are
pseudo data tr~~nsiers, Jn
rnod~:;, r he conttutler opi'!:ra.tes as lf in reJJrl ur
write mode. hin\'{wer Uw rnemorv and VO control lines arc not nctive.

transfers nre a special ('£1se of DI\!:\ tram,for. Chanm;I 0 i1;
the source Dnd channel 1 is the targ-(:t. In rnernor~/~t:o~rnernory transf<-:J's. tfu1n·
neJ 0 usPs un_e cy4_~h--: to rt:<.~d the data
and store; it in t11e t.enlporary
lt!C (Jn the
-cycle. ch,ann.el 1 vvdt·es the va.hte in tho teroporary
to the targ;f-1t l{_!f~ution.

Auto-lnitfalize
Rt:stores the Dl\l.\ dwnnel tu its original condition foliowing- an F:OP. ''.\uto[nitialization is accomplL<;hed by
the nriglnal values of the Current
i\ddress and Current \Yord Count registers frum the B;1s0 Address and Base
\Vonl Cnunt
The CPU loads tbe current
and base registers
which do not
during Hw JlMA &i?rvice. 'When i.hD rhannd is in autoinitialize niodn, the; m.'l'lk hit is not setc After auto-initialization und a wceipt of

a D\-1A n:q1.11>st. the channd cm perform fHvIA -,ervicc without CPU
intr:rventton.

4- 4

Priority
Tlw t'IVO tvpes of priority. fixed and rotating. are defined as follows:
Fixed Priority

ln fixed priority. the c hannl'ls am placed in order based
on the desr:ending value of their aRsigned number. The
assigiwd number rnng·e is from zero to three W<~;., with
zero <.is the highest priority.

Hotnting Priority

The channel being servir:ed is assi11:nRd lowe'lt priPrity
1·a!ue. and all other'; rotate to the next higher value

Address Generation
The eight. high-order <Hkln•ss hits (! £)-8) are multiplexed on the If() data line<;,
At tile S l state. the hlu!H1rder 8-bits are output tfJ an extenrnl latch and

pl<Jred on the system address bus. The low-order hits arc output directly from
tlrn DJ\-fA controller to the system address bus. For multiple transfers, such as
block and demand transfers. ttw addresses am gern~rated sequentially. Tlle datfl
in the external latch {high-or·der byte) <'an remain the same for me111y transfers,
and have to be changed only when a borrow or <:arry takes plact~ in the rmrmal
sequence of addresses. The rontr<.1ller executes SI :<;tates only when updating of
the high-order byte is required.

D.MA Controller - Hardware Description

4· 5

P•irt

iV\V

OOOOH

Bac;c mid Currvnt w:ldrN;s

Curn~nt ;:iddres;;

O\lOlH

OOUZH

vv
!l

000:1H

0004-tl
00051'{

00011! l

0007H
G008H

OOOflH

Chnnnrd

0
0

Base and Current w<ir<l •.:ount
('urn:nr \V(ffd count

8ac.e and ('.Hrr~~nt fh..Jdress
(:urre:nt Jddn;~;s

\'V

Ba:e;t~ ~nd f:nrrent

(:urreOt; V/Urd C(H_Ult

\Ytird count

B:1Bc i.md Current. addre1;s

Cnr--i:T,nt gdc!.n~~;>-,

I1aBf~ iHHJ (~urrnnt ;.vord r~ount

(:urn.:.'Ht "'h'ord r·.ount

\-V
H

(~u:i'f(~nt. riddn~:~f__;

\V
fl

('urrent \'\''Jrd count

Base and Current address
Bas(~~ arxl

(:cnUAH;~nd

St;ttur;

OOOAH

\;\'

IJ()OBl l

\\'

OOOCt-J

\'Ai
p

-"' ·~

OOO[)Jf

OOOEH

\\/

lhlOFH

0080H

~'{v

008 .i Ii

OOR'.~H

\V
\V

( \nTi!nt \·vnrd. (OU.fat

Registers
The DJ'\];\ controller has Hi I/O ports to acc\:ss 2\i internal registers.
Additionnlly the Dl\L\ circuitry bas four VO ports to acces'> four p;;ige reg!stn·s. Table 4.:'l lists the 110 ports and the registers accessPd.
Basf~ and Current Address Register
toOOOHi0002Hi0004Hi0006H)

LOW .BYTE OF' ADDRESS

REAU OR WRITTEN FIRS'f

1:::i

-- - --- - ---r

12
l1
10
8
----r--- ------ -----1-------1------------1---- -- --- r ------,-----------.
l:UGH

BYTE OP ADDRESS

READ OR

WITTEN SECOND

__L __________ __L_ ------ J _________ J _______

--L~------ _L ___________ L __________ _J

Each DMA channel has a Hi-bit basi• addn·ss
dre<:;s regish'r. The b<>se addres;.
contains tbe iniUal vnlue. v\'riting a
val.ue to the base addres;i .regi.ster initiaHzes the current m.ldrcss register i-tJ- the
same vahw. The current address register is incremented 01· decremented after
e'Jch trnnsfrr. \Vhcn the required number of trnuc,fers have n•:curred and tf
irnto·inithlize (sec the mode register! b erwble(L t-be curruit register is ln-

itialii.ed from the base r~gistcr
Bef<ll'C perfor.ming a .! !}-bit read or write. dear tht'
pointer flipiflop.
To write a base
. writ.e two. !'.!·bit bytes in succession tn the same port.
To read a cmrcnt register, read t.•.vo. 8-hit bytes in sw·ces;don Ln the same port.
In either cuse. t.hc hnv byte is accessed first and then the high byte.

Dl\1.A, Controller

H;wdwarp Deseriptiou

4-- 7

Base and Current Word Register
(OOOlH /0003H:0005H/0007H)

r-----·-.--7

---T··---- ----,~ --- - 1---------·-1 -------- --T--

LO'J BYTE .OF _C.URRRNT Y_ORO

READ OR WRITTEN FD~ST

!!_ ___________ _L__ _ _ _J____________ _L___________L___________ J __
15

r------,

11~

,---------

IH G!I l:l'ITE OF CUR.RF:l'ff VORD

Rl':AD OR
_L

_ _ _j

WRJT'l'EN SECOND

___ _J

'------- .L
Enf·h J)rvlA chara1t~l tuts £• 16-bit base 1.-Vord count- re[~ister and a 1<)-hit -r·urrenx
;-•1nrd count
~rhe ~;;-(due \'\'dtten to this
df·t+-~1-rnines lhe rnJrnb(~r
cif transt(~rs peeforn1td. The nurnber of trunsfr:rs is t.ht:
..,,.nlue plus
uw:. The r'.urrent hUrd count is decremented atter each trnnsfor \\-'hen tlw cur

rent ...vnrd Ct:ti.-~nt is decn:_'.!Xlf:l]tt;d behYrV zero i FFFFl1 L H tt~:rrninat ~~·nunt i>.: J2;0ner~
axed. '\NlH;n t:J:ie
nun1ber of transfi:~rs lurve iJrcurted nod if HiJto-in~Ji:..di:te
~t-;ee the n1otk~ n:gistr'.~rJ is {~J1~:1b}ecL the current register is iniria!i.?,ed frorn the
ho sf;

Before

a iii bit read r•r writl'. ch~nr the byte point.t.·r flipiflop.

·ro v.. rite a bn:-;e re~;ister, ;.vcite tvd.L 8~hit
in succession to the .i..;ftrn€ port.
'"i\_1 read a t:urrent
~ re-nd tvvo. H-bit
in Sttcces.sion tn the sarne pol.'t.
In either !_-·ns(~. U.1c lt.nv byte Is acct..;;~;scd first :;inrl thPn t1ie h_igh byte.

1- 8

OMA Con.trolh.·r - H.ardware

Command Register (0008H)

Blt

UiW Description

DACK SENSE · JJMA Ar:kn•Jwledge Sense
0
D/\CK sense :wtive low
lJ.A.C f\ sense act.i ve high

\\'

l!H.EQ SENSE· fJMA Hequ.;st Sense
o ·
r1RE'l sense acth·t> high
1 ~. DRCQ sense active !nw
0"

\,\'

\VRJTE SELECT
0 •·" Late write selected
l ·o::.· l~xtended write .;,elert•!d

Fur tho Vi\Xnwte workstation. thr~ ext.ended write mode dnes n•Jt
provide an ad(·qtwte write cycle. tise
the late write mode.
H hit :i equals 1 !compressed model. bit
is LJ don't carP V<•iue.
However. r:he \"AXrnatc workstation is 11ot capable nt using 1.·0111·
pressed rnode

PR
{) =

Prioritv
Fixed.priority 0 (higlw'StL l. 2. an<l) ilowe5t)

Hotating prir;rity

Initially, the priority Is Li1f' same order as in fixed priority. In the
rotating priority scheme. the •:urrnntly servici~d [)MA channel b•>
nmws the lowest prmrity channeL However. the channels
maintain their priority in nuJlicrk ordPr. That is. the priority
creases ns the clvmnel number .;ncreHM'S and wraps between channels :.! nnd 0.
.

Dl\V\ Cr)lltro!ler · Hardware De.~criptlon

TiMJN(%

0 ~"'"

Nnnn~d

r<':adiwrite

nnd ls
VA x~n.nte Wf~rksbJtln11 uses th~s
rc~-H.Vvvdt(:

:\ n~Dd/write

O{:(Un~

The VAX.mate workst"1! ion is nnt

b!.t n eqnalN J (ruen1ot·y to~1ncrnc(y enohicd~,, bit ;~
-ft;::n._t r~-~_re .,,,~_~l.ue.

c· r_~; - l ~(111t!'<Jiler .E.riabie
0

Cnntro1l!~r di~~ibk~i'.J
(~t.)nt1·\)ilt~t' (;11.~ibli-~d

'l-l/;)>i'.'-l l<L 0 AllDH!':SS HOLD
f)i::-iDbtc ch.1n-u1.el 0 ~1(__Jdress hohi
l -::::: En:Jb1c i_:h:u-.:nct 0 :idd.res~ hn!d

('l_-;_an:JeJ 0 add.res~ h.fild i_~auses U1t: L>rvL\ C(tnt:rnBe1 tt1 ropy i-.t
ir/t.e to thi~
nHtnlJer of de~tin;Jtion
!f bH· o f~qu~d~ 0

t.o-rneniorv disabled}. hit 1 \cbnrJ.nel 0 ad~
~

dn:.ss ho~d~ is a don't f·are value
0

MF tv!O HY-TO-.ME \! t 1fl Y
t.}

tvlt:.:1nnr_y-to~ rn(·~n1r)r~v transft::rs

r.lisHblr:d
rnerno!_""i/ tr<Jnsfcrs cn.abh~d

~rhi:--' ,_/ AXn1~-1J.e \VtH·ksL·.1tkn·1

does riot support n1er-r;ory to-rnen1(~ry

tr~-~-c:.sfers.

~llds R~btr,

i.~nntT(ils tJ)C (rperatt1.1n. (ff rhe rr?vl 1\ rontroller. it is cleared bv
n h~ffd\vtire rc.1.;.ct. or a rn~-1ster cle;-u· in.··~1_. ruJ~~tion

:t 1{l

Dl\'li\ Contrnifor - Hanlwan:

\Vrite Single Mask Bit (OOOAHl
l

DON'T

MASK
IHT

CARF.

CllANNf:L SELECT
-- __ J ________ .

Blt

R.,'\V

Descriptiou
DON'T CAHb iwtv valnel

•)

J\IASK nrr

0 "'-'
l -,,~
1-0

Enable the ''PlPcted channel
Disable the sel.ectctl duurnel.

CHANNEL SELECT
00
Scl~•ct thannel 0 mask bit.
0I
Select channel .! mask bit
10
Select chm11wl 2 nrnsk bit
l. l.
Sple-<.:t- ch<innE'I ;) mask hit

E<ich channel lws a mask bit. which cnn be sd to disubk the incorniug· UM.A
un f•:OP and

reqtwsL These bits Hrc ~:ct if their associated channel
auw-init!alb:e is nnt F•n:1hied.

\Vrite AU Mask Bits (OOOFH)
5

_[___ 3 ---,

r-·-----~r

MASK BITS
!
C:llANNEL CHANNEL CHANNEL CHANNELi

DON'T CARE

.__ ____l

Bit

----.--

0
---·---,---

J __________L

------- J_ __ -

_J _______J ________ J

n:w Desn.iption
DON'T CARL
Mi\SI\ HITS
Enable dv_, indiGited ch;urnP! \CH AN "-JE L '.i O!
Disable the indir;itt>d drnnnd !Ul/\NNEL :Hif

DMA Cm1.trollcr - Honhvarc lksniptfon

l\·1ode Register (000BEU

Bit

H.'\V

De<.niptirm

7-6

OPfR1\TION l\10DE
1)0
!Ji'mrind modP
iH

l0
lt
5

'.~'ing:l.c; mode
fllo{k mode
Ca'.iead.:: mode

il\l('.f(JDECH SELECT -- lnrn'mcnt:Liecrenwnt "le!cction

0
1 -~

lncrcrnent ~~~h~cted
Decrement sdcr;ted

A. llTf) IN IT - Auto-1nitfa lizatinn c:ni!hle
o =- Lli•,uble ~iuln-initfa!izi1tk1n
l -~
Enable I.tutu-ini!.i.;JJiz;:itinn

;J-'.>.

\\'

THANSFEH TYP8
00
01
\\'rite
ln

H.(~acl

Inv;:did "l:llu;;
A, r+.·ad tr'ansh:r 1no--.r::is d::tta -frnn1
writ.t< tronf~f~·i· n1t.P..-(:;;; dat.~1 fn.nn tJJ(~

lf hits '7-6

1-0

CHANNEL SELECT
00
Ch;~nnel 0 ~e.te~ ·ted
0l
Channel 1 select<'O
~O

('..hanncl ~~ :'Jelccteri
Ch;;i:1111r.d 3 seic~~ted

to mcrnor\r Tlwt. is,

Hequcsi Register (00091-H

7<.I

DON'T (',\RE i;my ,,duel

HEQUEST BIT
0 ""' Fkset r.hc inriieated r•Xtncst bit
1 '°' S1•t the indicated request bit

CIL\NNEL SELLCT
00 "Chunnel O
Ol
Channel J
10 ~
Chnnnel 2
I
Chnniwl :~
The DJvJA controller respunds to requests for Vrv!A service frmn both software
find the DMA rNp1est signal. I•:ach channel has a rt•qu1•st bit that can be set or
res1•t as det•·nnined by the ltf!fJUest register. These bits are not masknble and
aro
to pri.oritlzation,

4- i:~

Status Register iOO<J8H)
5

r·

-r·

r··
f

-·-,

.
DMA REOUES'f PENDING
TERMINAL COUNT REACHED
[ CHANNEL CHANNEL CHANNEL CHANNHL CRANNRL CHANNfl,L CHANN.EL CHANNEL

]

L_ -··- L .........J- ..·--·-· L _____

____ _J_ _______L.--.-

Dl\.!A. HfalUEST PEN iHNO
Indicated clwmwl does not. ha•:e a reqrn:,;t pending
\CH/\NN!::L :Hi\
i{:HAN NEL :Hi,1
TEHMINAL C(HlNT RI•>\t'HEU
0 -:-;
Inrijc,·1te<:i ehannr~l bD}j 11ot. reiH.:tie(J the t(~rrr~invi coonr
iCHA.NNFL :Hn
lndicr·ned channel lul~-i rcnched the terrnin.ul CCHJnt ot l'.~xt.r~·n.H:d
l'XJP
lCHA~·iN LL :1 Oi

Terr1poni.ry Register (000CH)
4

DATA
'
'·----'-

;:nnt:rr;tk~r

·---

sU.!fes th~.: .~._-,urc;_" n;:r,c n: this rf..~gl.~ter. ·r:1~:~

:1.an}..\~.:Jrf· (CSt·t ·J~'

n1;}-~~tc.l

,!·:fr.'..:_:,,

Progrannning Exa111ple
!nit!~dizi.ng Uw

•
•

82'.'.';'A DMA controller

Emibiing and diM1hling

1'llilnncl

Pn~qJ~n·irlg f1 ch:a.noet f1~:;r rb1t>t tn.t.n 1~f('~r

The

pnrvides routines as descrihr;d in t,Jw

dm;; nµen

CAt'TION
oi fi1is d:f'v'i.t~~~ C<ill

or
ca.us(~ Uu:

V t\~{1nat.t~ ·'V·Prkstation t.o rnalhinction. 'J"he Bc:ope nf
the
is }irnited tn t:hP· conte:..~.t
in
thi~ rnuru.1aL :\Jr.) other use i.;.; intc-nded
1

Constant Values
dres:_" of thr; ]11c<.lfr:c.n:cd
CJJANNEL1 ddine tlw

request

'"''-+/

ff def l :n t~ DMii __ PAGEO 0 _)~33

#define D~~_PAGE1 Ox80
#define D~A.PAGE2 0~81
#define DMA.rAGEJ Ox82

•define GHANNEL1
#d~fine

OM.A page tcg:i ~5ter f; l/n ~ddree.s
i/O :<drJreas
Dt" A page xeg' atf-'.'r
I/U :.~ cki! ~ss
DMf\ pagl' reiststi::':r
DMA pa.g,(_: .t eg:L B ~-,~~':, 3 J n ;id!iress ,, /
~

~:·

0~01

CHANNEL2 OxC2

Sod fH 1, r:hann~1 0 tiH ,, a lue
seitlct chan.tH)l
btt '·'·'~.) 1.t('
thanv.=_eJ 2 bit ','al ue
~~<f (1t;_ t
g,el~ct ch;>,nn.; .i 3 b:i t -:.,ra lue

'
-?

1~ command regiclt2r bit de~it1itions */
#define MTM EllA (h0t
/'~ Memory·-to--·memory •n~blc
#define HOLD~ENA Ox:O;~
1~ channel 0 hnld address enable
#def :ine DMA_DIS -n--:04
/* dma controller diaable
lufof .i ne c TJME
0;·;08
;, compressed tlmi.ng
1ld.ef ine ROT_Pf!I 0.z~.<)
1~ rotating priority
#define EXTD.>m Oz?O
1~ extended ~rlte
t)):4Q
#de:f inP D!tEQ_LO
1,·. DREQ activA wtten low
#def lne DACK.HI tt<fH)
!* DACK activt~ wbe11 high
i~ ntatun r~gister bit dt::-·.E :tn it. ion~ ',~ /
I~"..:. ch;;1nuPI
#define C!l0 .. 1G
0xGi
o~,~.02
#def int; CHi._" TC
chann(.'J
#define CH:2 .. Tr"'.
O_.zO.:l
/·-":- charu1f..'i l
! :-: channel
Ox08
#def im' CH:3 TC
#d~fine CHO_ ltEl~
0 . ~.10
J
#de-Cine GH1 REQ o.~~20
./ •t
1Hlet 1 n•: CH2_ f(E!i Ox•\O
.Iv:
#define C!!3_HEq UY.'.80

t~gist~r

bit dcfintLlt1t\s

TRAN \FR

C?.00

#define TRAN_WR

Ox04

Jid.ef inc TR.Ai~ an
#defirH-" AlllD_T.E

0;:.lO

mode

ff:d.~fine

0 has n:rnd:1<Jd Lerm)nal •:oun1:
:..l h1i.a re~_ch~Hl t>f.'rm.tnaJ ~OlUlt
3 ha~ T<:llrhed termhui.1 Ct)U..!1 t

v~rify transi~r

*/
~;

•/
t/
~I

"-/

write t1anafer •/

0 KD;:~

ce<iid

tra!~s:i·i:-t

~ .~

auto-initialize enHble •/
addJ.--~ss

dec:t fHP£~nt

u~20

MODE~ tl'.~

Ox On

/;,= dennuid mnde

#define ~ODE S!
#definr MUDE_BK

Oz40
OxBO

ltdcf il1\f-\ NODE_.cs

O:zCO

~ reqaept reglat~r bits
#dBf:ine BIT_SET G.~04

•f

4 haa reached Lenrd.nal count
cha1tnel 0 JeqmH<ting s-er 1.:ir:e
r.;;-qu.eHtir. . g servJcEchann<'"l
<:harmel. 2 requ<:"at.ing r;erv:ice
chH'O.llf!l 3 rt~qnie st i.ng :t<t'r·fice

#defjne ADR_DEC
#define

sirigle

nlorl~

1-/
~ 1

.i"' b1od-: rrode

caRcade mode

:- aet aelected ~n•k bit

Data Structures
The strurture DMA ('H4NNRL resembles the [i0 space of the address and
word count registers-tor a dwnneL Multiple instances of this structure <JrC used
in t!w declaration nf the D.MA CONI'f?OLLFJl stn1i·ture. The
D}vfA C'C>NTRO!LER strnctur~' defines the 110 space of DMA controller intE•rnal registers. The value Dli!A !JASE defines the base address for referencing
the strm:ttire D1\fA CUN1R(JLLR!l.

*· dec1are strw::turtls user! in 8237 DMA e1.amp:le

!• define dma channel 1/0 structure */

typedef stru.ct;
{

1.msigned cha:r bc._addr:
unsigned char be.. w<n:d:
} DMA_CHANtlEL,

write base address, read current address -/
/c; wri.t.e base "iQTd, read current word

d~f:ine

t,ypedef struct

drna controller l/0 struf'.t.u:r-o -+/

{

DMA. CHANNEL rhO;
OMA.CHANNEL ch1;

channel zero regiaters ~;
/+ channel one registers ~;
DMA. CHANNEL ch;~;
/• channel two registers */
/ t· channel three registers ,,;
OMA.CHANNEL ch.3;
unsigned char car;
!• write control, read status •/
urrnigned char req,
/i< write .recp.te$t :rPg:iater :*'/
unsigned char wsmb;
I write single mask bit •/
unsiguBd char mode;
/8 write mode regi.ster ~!
mrnigned char temp;/' write clear& byte pointer flip·flop, read temp ~;
unsigned <:bar maot;+,( .. c Lr:
;~ write master clear/reset •/
unsigned char clr_mask.
/• clear all mask brts */
•ma i.gried char wr_mask;
DMA_ COiHROll.P.R;

#dt>f in;; DMA .BASF; (OMA . COtlTll.OLLER

) OxOOOO

DMA (\introller

bat~e

arldress

Program.1ning: Example

4 - l7

Initializing the DJVIA
"fhe [;~-1l\ ,~:untnJHer is ~~·-dti.:tUz;;_::d by
d i\1:-\ST-Eft (~L.Er\H, iru:;tnJc::-k;n
'rh~s c1ea::--~ ?l! b!.t.:3 ln tht; (>~.:1nn1a.1:i:d n3g;t:J:r/r and
dls~ibh:-::s t·he Cf~ntrnik•:L ~f) 1 e ~-iecond ~t.1~-~trncu'.~!L \.\thi(·h
t~iat ttH~ n:Jntt"ollcr is dl_~,9cbl~.:d~

res~~

}

D~~ -:ontrol.l~r

Opening a DMA Channel
'I'he dma open function assumes that U:ie rhmmel is l':urnmtlv disabled. It
writes valid values to the registers that control the indicated. channel.

F'or this C compiler. offset 0 In the dat,a segment is used unly for monitoring
NULL pointers. With a :zern word count, an inadvert.ent data transfer nm move
only one byte before expiring.
The last. in11t,ruction enables the indicat.ed channel.
/****~****~~*·~·**********~****+********•*************~****••*·~···*****'
/* dmau:ipenO .. open 11 DMA channel
*/
/***********•*•**•···~~***•••*****••••••*****************•*****•*****~··!

dma_open(cbannel)
/"' whkh DMA c.li.11.ru::tl!'l "to open */

int channel;
{
OMA_ CONTROL I.ER *pdc ~ DMA .•llASE;

DMA •.. CHANNEt. "'pc.h:
Jnt i;

/* point to DMA controller ~/
/* pointer to a channel si;ructure '</
/* loop control •/

for(i "'d:umnel, pch"' .lipdc~:>chO; i; :i--)

/'< discover which channel *-/

/• point to next channel -./
outp(tpdv>mode, channel);
I* clear mode register ior this channel •)
outp(~pdc->req, channel):
/t clear diannel request for this ch11.nnel
outp(.kpdc->temp, O);
f* clear first/last flip-flop •/
ou.tp(lpch· >bc_11dd.r, 0);
1~ writ• 0 to low byte *f
autp(l!:pch->bc .. add.r, 0);
h write 0 to high byte "'/
otrtp(lpdc->temp, O};
f* clear fi:rnt/l•u•t flip·flop */
•:mtp(&pch->hc,word, O);
I• write 0 to low byte */
outp(&pch->bc_word, 0):
/ct write 0 to high byte */
outp(&pdc->wsmb, chann~l);
mask bit for this chann•l •/
pch++;

0• /

}

DMA Controller · Prngrumming Example

Preparing a Channel for Data Transfer
The dmu
Junction prepP.res ;1 channel for dntu transfer. N;~xt, !he fum:tlnn disal;ies the channeL It then inifoili.?.es the page. address. wurrl •:ount, and
•node

NOTE
Before writin~ a LG-bit
• the byte pointer flipiflnp must.
be clean.:d. Tli1:,; seq1wn•:c
bytes ht t!w
con«ed locrir.ions. Bee.a.use interrupt
{:ould disrupt the
p.nwe5s. the ciina
funct.inn
CPU interrupts
betore clearing the hyte pointer fliplflop. lutern.ipt.s are not
enahled until a ft.er dw J G·bit
luve bf:en written.

/* dma_tYannfer{) - 9et paramel,ers ioT a OMA trannfer

* transi'er on which OMA <channel ., "1

Jrit clwrmeJ

int page_·rnl:
ui1aigned chnr

-r:/

.1 1

page rcgist1n n:mtcrdn ' /

/x tra.nsfer address ~!
I* co~1nt to transfer t/
/1 tranefer type •i

~:,add_r:

nrudgned int count;
int t type;
{

OMA . C!lNTRDLLER i•pdc

DMA .. BASE;
!~

Df':A .. CBANNEL rpch;
nnstgned tnt pagc,_i:eg;
int, ch_mode;
lnt i11tr ... fl11g;

!~ paint ~o D~A controller ~;
pointer to a channel. structur~ ~;
!~ whit~h page x~gi3tex to wr·ite ~!
i ,·, drnnne ls mode , :'
I' t<> IJoJd CPU Jf 3tat.e

r.w-i tch(cha.1Yne L)

f
{_'.US~

I channel 0 ? I
pGint to channel 0 iegi.aterB P/

pch '"' kpdc ·>c hO ·
pag<' .. rPg ·" Dl>'A_PAGEO;
ch~mr:d.~

RPt page reg1nter addrena •I
/:.

i'Uit.o~ ini t i alizc &

br..-·ea~-:;:;

DMA Comroller

Prow::muning I<Jxnmple

J.ncr<Hncut/dec,rP.'.":ent "'/

case l;
pch

·~

/• channel 1 ? •1
&pdc ->d11;

page_reg
ch __ mode

DMA.PAGEl:
0;

/• point to channel 1 regiatera •/
;~ set page register address ~;
/M auto injtialize k incremen·t/decrement

I* channel 2 ?
point to channel 2 regiatera
!~ set page register addreaa
/-• au·to-inl-tialize I;; increment/decrement

"/
•/
+/
.. /

break:
i:~ase

pch

&pdc->.;;h2;
page_reg •- flMA.PAGF'.2:

cb_mode •MODE.SI;

break;

case 3'
pch •- &pdc >d13;
page __ reg -- !lMft. PJ\GE:3,
~:h_llHJde = 0;
break;

_l,, point to
!~

/* channel 3 " */
channel 3 registers ,/

!~ set page rRgiater addreso •/
auto-initialize k increment/decrement +/

}

oHtp(&pdc ->wsrnb, BIT _SET I channel); i•' net ma!'!k bit for th to channc-l ''•/
outp(&pdc->req, channel);
i* c1ear channc-1 requei;t for this channel
outp(&pdc >mode, ttype ! ch __ mod•~ i channel);
/" set, mode register '/
intr_flag '"int.off();
/-'•no interrupts please•/
outp(&pdc->temp, 0);
/ 8 cJeax first/la.Bt flip-flop x/
outp(&'.pch->bc_addr, (ungigned int)addr & Oxff);
i• write low byte"/
outp(&:pch->bc_addx, (unsigned )nt)addr >> 8);
/* write high byt-e •/
outp{&:pch->bc_word, count & Oxff);
f-1 write Iow byte '-/
outp(&pch->bc word, count>> 8);
write high byte•
i.nt _on(intr __ flag):
/~ allow interrupts ~
outp(page __ rep;, page_-ra1) /" write the page r<>gJster ~
autp(tpdc->wsmb, channel];
/•clear mask bit for this Ghannel ~
}

DIVJA Controller - Programrnin@. Example

4- 21

Disabling a Dl\IA Channd
T'hc dnul eiose tuncdGn eln~f',s the chDnni:-d by .rna~k.ing tdiBatJiingt th;:.tt eh~u~·
ners request
Ene.

*/
~*****~:~~~*~**~***•*~~-·:~~4/

dma_ ·::loBe(channe.1)

DMA CONTiWLLER 'ptlc

DMA_IlASE;

}

4- ')')
~-

DIV1A ContrnHer

Chapter 5
Real- Tin1e Clock

and CMOS RAM
Overview
'fhe VAXrnate prncessor board c•mtains an fvlC14GfllS real-timt· dock. The rcn1timc dock has the following fe0tut'es:
clock with a!ann and 100-ycar ciilentfar
•

Counts seconds. minutes, and hours of the day
Cmmts davs of the we<cl·:.
o! the month. ruonth, and year with w1ro·
rnatic n1d:of-month and !cap year
or binary..,~oded-dedmal OlCDl representation nf d11tr;. tirne, and
abnn ithe HtJM BIOS and l\1S-DOS use BCDL

•

'.'.4-hour clock or 12-hour clock with tLm.i'p.m. indication

•

Intenwl time basH and uscillator

•

Externiil tinw base :·l2.768 !\Hz crystai

tirne npt.frin

!J.4 byw, low pmvi:ff statk HAM 0 4 bytes of n;gisters and 50 bytes of
p11 rpo:'le HJ\ l\ll
Prognrnm111ble interrupts

Time-of"day alarm. om·e·pt>r·second In onn•"per-day
Periodic interrupr, rates fnmi ::io.;:, ps to 500 ms
Enrl-ofnpdate i11terrupt

Reul-time Cfoek und CMOS RAM - Hardware Desniption

:) -

i\dditional Source of Inforn1ation
~><kiitional

infornwtinn on pro

Battery-Backup Considerations
To keep time and mointai•1 RAM. when svstcrn puwer ls off. the rc:1l-tinie dock
a baU.C'ry-backup source. The twn lithlnm bl!tt.erk:s in tlw VAXrnate
box
the only b;ittery power ,,,"iurce.
Mll'E
;rhE'.~ 1i~.l1il1nt

used in the V /":J,,.)~_tYi~-~te e;.~_Jnlnsi(in. t1(1-:v:: bas an
life e:-;µcctancy of G y~·ars <w.d a shelf life of 10

Addressing the RealvThue Clock
The real-time ck1c:k H11'C! is :nldress<.'d
the cont·~nts of an 8-bit lat.ch ,1t !.10
port (}070II and the HTC (fata i::i mad or written thnJUgh 110 port 007 tH.

NOTE
The RTC addre:«; latch is write
Bit 7 of t.he HTC addresg
latch (If() pClrt OWWHi is the nnnmaslrnble interrupt (Nl\·lU mask
If bit ';
zcrn, tbf' N i\H i« enabled. Otht'rwlse. tlw
i:s disabled p.·,y more information abunt the iionm;iskah!ic.'
iut(~rrurt~ see
3 and 16
The HTC dedicate'> the• first H
of H.Al\.l WOH tln·omib OD!H ;is registers
for t.he real-t11rw clock hinctions. The remaining 50 byte<; of HAM WE!!
tinouirh TFHl ~,1:0 not dedk;.1tt-,d to tfo,, HTC Table fr·] de»cribes the RTC ad·
dress map.

Tab!P 5-l

Rea!!J'ime Clock Address Map

Lalrh Value

Ri\V

Loeatk•n Accessed

OOH
OJU
ll2H

H/\V
R:VV

04H
OflH
OGH
07H
U8H
09H
OAH

BFW

Seconds register
Seconds alarm register
I'd inutes register
Minutes ala.rm register
H.nurs reg·ister
·
Hours al;irrn
Dav·of-week rcg·ister
Da)•·of·rnonth 1:egister
Month register
Year regi!ltN
flef!:ister A
Register H
f!t,.&r,ister C
HegistPr n
Hornarning flO bytes of HTC HAM *

H/W

oaH

R/\IV

RiW
HiW

Hf\IV
R1W

OCH
ODH

R1\·V
H/VV
H:\V
H:W
ll/\V

\WH-8FH

H.'iV

OBH

* See the definition of the structure HTC in the prngra.mminf}; exump!e.

Real-Thne Clock Registers
The reaHimc clock \RTCl has two types of reJ<i:ister<>:

•
•

Data th>cf!i.tons OOH tbrnugh OUH)
Control. and stat.us {locations OA.H through ODH)

Dat.a reµ:istet<> .are vDlirl only when the HTC is not updating. During dock updntes, the RTC disnmneds: the dat.a registers from the RTC bus, The spedfics
ot data register processing are discussed !awe,

The cimtrol mid status reg:ish!rs are available at all times

Re;iHime Clock and CMOS RAM , Har<lware Description

Register A~
- 'V\·,.rHo O/,JJ to addre.'E.; Ia.ti:_~b ii t fHJ70l"-i
f)atn - ffe;1fl ur v.'Litt; d.aia nt addres;s 0071.fT.
l

RATE SELECTION Bl.TS

Blt

t·or ;1[} Ur:Te ha~e;~_ at ienwr 24~1 .us rf;iL;ji_n bt.~foro the
fire a•/;)il.ubh~ for
~n k~:ss

tbf:n 244 iiS-

hit. For th1:;_' :1:? 7tifi Yd {z. tin1.c br;sr:~ the
;! I ro the
~-~nd ch:'Dn~ U.tf~ UlP st-at~_,1:;

B SET
bit i\ fH1rti:

UIP bit.

'°")•-:i_i:•

~~t·rn"·~,,.-:

-d+:pr r-·,..,·Hv·: 1 )~~

di·•. ddc-:!· c;.:~~eL the

"-~~ " ~)~-.-<::i~·'-;r..{~~"\r/\_)~_)1•i;;_if_-~: ~;i,··urJ.~stadon tin1t: ba.-~~~
1.'

""f;1e.,:;::: b>:A; .~eicrt 1)nf1 ot 15
b1r d~vidc:r. 'rBhh:: r-1-Z ~htn/:--s

RS2

RSI

()

(}

RSO

Pe1·i<idk interrupt RnL>'

..
7.81.25 us

n
0
!)

fi·'

;J t 2fi0 rns

f:;00_{} rn~

ReaHime Clock 1wd CMOS RA1\'J · Hardware

r-·---I

SET

L_ ~--

H/\.\'

SET

to occur once per s.econ·cl
eyrle in progresi; nnd inhihli update
iThis allows initiali?.ation of th.: date. time. and

!. "'-

until

alarm
A hanlww·p reset d~l<.?S not niodify the SLT bit,

(;

Hi''.'V

PIE - f'er\odk lnt.errnpt En;:ihle
0 o::· Disable
·interniptcs {default valuej
i =
Em1hle periodic
s .ut Uw rate specified by IlS'.:HlSO

i11

A h:1rdwme l'flM3t dmu~ the Pl!'.: bit to n.

n:vv

ALE - 1\larm Int.m-rnpl Ennble

Uhwble alarm interrupts ~default valuf')
F:nalJle alarn1 int.errnµL~, !The interrupt trequency depend& on
tb.f (.ont.ents of the alanTt

A ruU'(hvarP rPSt't clears the Al L bit to o.
"!

f\!\V

U!E - tlpclan.:-c11ckd fnterrnpl: F.nabk
0
Di~;;;blc Uw uprk•te·t'nded !ntnrupt. 1.default valtH,.f
I
Cnabi» the uprlilH>endcd inwrn.1pt
"CC

,.:\ hanJv,,,'u_r~~: r-e~t~t or

!be register H S!:':T bit dears the UIE

bit t.o n.

Hi\V S!,;)\VE ·

n
1.

\N~-F"'

Enable

the o.:<iunre-wave
(default value)
Bn<•hk th~ sq;JFH'e-wnvc rnit:put.

mitput is not cunm'•~tcd t<• mtything, ~·o the
bit should
be written a~; fl_ A !rnrdware .n.~~e!. clears
th•: St,l\N f:; bit to O

Tlw

~le}\\'

!) ~ (;

Real tinw Clnd~ and CMOS R.A.M. - lfardwan; Der;triptinn

R'\\'

DesnipHon fRPgistcr B · couU

fVW

DJ\.l · Data Mode
0
Binary·code(hiedmal. \BCD) data format used for date, time.
an<l alarm registers
Binary dnt.a format used for date, t\nw, and alarm re€:isters
A lrnrdware reset cliws nnt modifv the DM bit. However. the HOM
mos d('ars DNI to o.
·

l:l/\'V H.M · Hour Mode
0
Hours rng·ister and hours alarm register use a l 2·honr dock
with a.m. m: p.m. indir.LJl·ion
Hours rngist.er and lu>urs alarm rngi'<tcr u..;e a :Z4·hour clock
A hmdware reset does not mrJdifv the H!Vl bit. However, th<) HOM
BlOS sets Hl\1 equal to l.
·.

n;w mm · Daylight: Savings Enable
0

Disable daylight savings
Enable daylig-ht snvings. Driylig·ht savings changes oi::cur at 2
;i.ni. on the lnst Sunday in April find the last Sunday in
October.

f\ hardw£Jre reset does not modifv the flSE bit. Howevec the
Hmvf 1:3108 dears DSE to 0..
'

Real-time Clock and CMOS RAM - Hnrd\H\J'e DescriµHon

:i ·- 7

\,V~,~~~n nnt' er P~(E~~ f•f th;:·
;:<:-::·!.'~ ~:he I H~lt"' hit. tn

Pff

:•rL = 1

;\lF

Al;<~

V·/.fH: 1: r::~gist(~!- H. fit ~·\jj;~: (~q1;;.;:1:::: 1 _ the ~JI F' 'bit h~rhi":C~.t'.t:~~:: t)1f·:~ ~:t;·~"J:·
/'it :.h<~ t~rd (~~ ~::~:;en :J~Kl:~t..f: (}Ck~. t~.,,,::
0

~.-~t :}7~-: ~1-~)dt1te-n.~1f~i::-{~ ~.ncernn.Jt.

Fri~c· se.u~ th ~~ bH t/~1 ·1 ~H'..c. ~seb; JHJ;!·~4"1.

•c_'.1r~" :jli ~:·~ir.s ~D

VRT

Bit

R:W Dnscri1>tion

flJV\'

VHT , Valid HAM and Time
0 -:o Since tbe last timo this n>f;ist.er wf1s: read. tht! power-sense
circuitry det.ected a loss of power to the HTC. The HTC reg·
isters and RAM cnntnin inv;\lid data.
Since the last tinw tbis register was n:ad, power tn the HTC
has n:mnioed stable.

Heading this regbt1or sl't.':i the VHT hit. It is tlie only w1jy to s<.:t
the VRT bit. After setting the date, time, Ill' 11larn1. n•<1d this
tor so rbat the VHT hit indicates that tlw register>< are vulid

\ hardware reset does not i.nodify the V RT bit
iHl

l11111l time Cfock and Cl\lOS RAM. · Hardware Desedptiou

i) - 9

Real· Time Clock Data Registers
The revl·time dock !H.TCI formats the date und time in dthcr binary or binary··
coded··decimnl lBCDL All data registers !OOH through OOH) mnst ust' the sanw
format. If the data formnt is changed. tlH~ data regl1;ten; must be initfalize<l in
the nnw format- The HOM BIOS uses the BCD daw frmnat. Uir 2 of register
B ronirols the format.
The HOUH !v!Ol>E bit in 11eg-istcr B f'Ontrols rhc range of the hour nnd hour
nl:.irm registers. \Vhen the HOUR 1\:lODE bit. is set ll I, the hour and hmir
alarm
have the rm1gt: 0-23. When the 11'0tJR MC>DE hit is dear \0).
the hour and hour nlil!'rll registers ha1·e the rnng·cs L-12 iu.rn.l and J:,~9·140
1p.mL

The lwnrs, niinutt.'S, and seconr!s nforn1 rcv,isters h:wt' m1 add.ition<li range nf
COH·FFH. This is nn alflrrn register don't care r:ndc. Fnr more inforniat.iorL see
t.be alarm description. T<1ble 5-:l shows the fornwt. 1u1d rwig;c-; of the dflt<J
registers.

5 JO

H(ml timf· Clnek aud CMOS RAM · Hurdwv.re Destriplfon

Tab.le 5-:l

RTC Data Regisl.!!1' RangPs

Lntch
Va!u('

Hegister

Functi.un

Binary Rang.;,

BCD Rang!:'

POH

Se(onrls

All modes

0-5H

OOH·5!JH

OUl

Seconds
Alarm

Specific time

0-:19

OOH-59H

Erwh second

1.92+255

COH-F'FH

02H

Mirmtes

All modes

O·M>

OOH-59H

OHH

.Minutes
Alarm

Specific time

()-!)~!

OOH-59H

Ea di minute

192-255

COH-F'FH

04H

Hours

24-hour mode

0-2:!

OOB·WH

12-hour mu de a.nL

1·12

01H-12H

12·hour mode p.m.

12~J-l40

8JH-92H

Specific timr:
124-hour model

0-:::~

OOH-23H

Specitk time 112-hour 1·12
mode a. nL,I

Ol.H-12H

Specific ti me {l 2·hour

12D·l40

8lH-92H

Of:dl

Hours Alarm

mode p. Ill. t
I H2-~(16

COil.-FFH

OHH

Day-of-Week

1~7

OlH-07H

07H

Day-of·l\·1onth

1-31

O l 1:1-3 I H
OlH-12H

Each hour lall modest

08H

Month

1-L:'

OfJH

Year

(l.fjf)

_.--·-~

·-

---~~~·~-----,-··--~---"--~-·

-~~

-------~- -~~,~-~--- ~- ·--~~-~-~---~-,··--~----,-··~--~---

OOH-99fl
-·

---·-.--.

-·-·····"-·~·

Real·tinw Glnck and CM.OS HAM · Hardware Description

i.\larn1s
l)urillg c•ach rnal-time dock IHTCI
cvde. the HTC compon!s the hour,
minute, an<l sccnnd
lo the corresponding alarm
H ail of the
time
mat.di nll of the 11larm rcgisti"rs, rlw ffT(' sets the register C
ldF. IL when this occurs, the reg-bter H aform interrupt enable iAIEl bit i~
eu;1bled, the alarm inten:upt
lRQH.
An ahirm
valne in the nmgc CO!!-FFH is a don't care code, Wheo un
alhrm rf'gister contains a don't. care cud11. that Hlarrn regist•_n· matches any
va.luc i.11 tbe
time

'fable 5-4 sbows the eight di.ffornnt type~ of aut.ornatic alnrm r:ycies
the renl-tirne clor:k iR.·rc~L
T11ble i'i-4

HTC t\utnmatic Al.arm

Hour Alarm

MinutP Al.ann

SPc1md
/\J11tm

Onr·e per serond evtry second

COH-FFH

COHfFH

CllH,FFH

Once per 'i'.cr:ond for ;;

CftH-FFH

:Speciti~d

COHFFH

one~111inut.e ~p::-1~1 c?}0r,Y' hut1t

Once per second for a one-

8pedfied

COH FFH

rninut.e spn.n e\·CfJ/ :~~·J h,un.rs

()nee per second fc~r .-:1 OIH-!-h•:JU.r
span ,_:,ve:ty 24 hours
(lcH~c pc1

rrd.nute e\'er_y ntirrnt-e

COH-FFH
COH-FFH

(h1ct~

per rninute for n DfH?-~hour
span f~.:.:ery 24 hours
()i_~ce per hnur £Vc:f}' houc

COH-FFH

COIH:FH
CoH-1.FH

COHF'F'H

Specl.fied.

Specified

Once every 24 hours

/\JsrL tberp i~ ~1 nnnautornatic ,,\'i.1.f t.o u5e H1e alarrn functlort. ·rn use thi~
rnc:t.hnd. ser a
nJar1n Un1c» /\.L each
~~larrn interrupt. S(;".t i)v3
next specific olar!'tl tirT1e,

llpdate Cycle
Onee p<'r seumd, the n'nl·tinw clock (BTCi porfonns an upifote
With a
:-12.7G8 Kllz time bai>e. the upd;1ti> cycle requires .Ul48 11<;. The 11pdate cycle
the foliowin11; steps:
The HTC .9ets 11 i tilt·

A L'lP biL

Aft.er 24 4 .us. the RTC disconnects r.hc dat.a registers trnm the external
hnB :ind conned,;: them to rhc internal bus .
., T!w .HTC incrcnients t.he seconds register.
•

Th1• l·rrc checks for an o,·erflow cnndition. !f no overflow condition l!xists,
th1C• HTC g<)\'S to the tW>»t step. Otherwise. tbe HTC zeros tlw register
and increments the IW:\.t regi.<•ter in the s•~ries.

•

The HTC comrwres th•: hour, minute, and 1-1econds regi.sters t.o tbe cnrre.,ponding- rilarm n'g-iskrs. If a match rn:cnrs for all three
the
HTC sets n t the rei;dster C ularrn fin!:!: IArFL

The H.TC dis<;onnerts the data
ncns them to the external bus

frorn the intern:1I bus and 1·v11-

The HTC clears HH the !'"l<ist.Pr A. U IP bit.
• 'fhe Wn. sets i l) the rci;dster C update-ended interrupt fh1g 1UH'1
re.;;istt'.rn are discnnnect.ed from tlno externnl
while an 1.irxfate is in progTess, rellding tff writing fl data rngister prnduces invalid results. Use otw ot the following methods tn i\vnid update
bus.

iVlonitor the
1\ update-in-progress !UlPi bit. The update cycle
begins 244 11.<; after the HTC sets t!w l! IP biL Thus. if the U IP bit is
de;ir t.fw data regist.ern will rpmtdn valid ior rn !cast 24,i /f<J.
•

Eimble the upd;;tr>Pnded interrupt. This interrupt occur;; nfter cvpry
uprlate cvde. Tlw dat(• and time registers rl:'main valid for OV! r !19\l ms
after tfa; RTC Slc't'S the UlF. ft thf~ processor must handle an t.~xcessive
amount of .intcrrupt.s, the inwrrupt handler for UK: HTC should also moni
iol' tlrn UlP bit.
0

Monitor the register l' periodic interrupt flag IPlFl Tile periodic .interrupt
is syrv:hrnnized with the update cvde. For any
periodic interrupt.
there 1s <t time alter the interrunt. when the cl<Hil registers ::ire valid. For a
32.7G8 KHz time base, use on!;·· the rate11 betwepn :i.UOt\25 ms and 500
nrn. lJ01e tlw following fornmli:i ·to cnlculaw the valid tim.e span:
Time Spno c-c. 244 p.s i· OlATE 1 21
ReHI·tiinc Clnc.k and CM.OS RAM - Hanlwun• Description

Interrupts
Penodfr lu terrupt

If the PIE bit is set 1IJ. the periodic interrupt trig(icrs rn.Q8 ai the rate specified by th..: IV\TE SELECT bits .in
/\..

Update-Ended Interrupt
If tlw UTE bit b set Ii.•. !:he update-emkd int..;rrupt triggers IIH;Jii oner: per
secomL The r11c'XT RTC update
start:s I 000 ms after the l•pdate-ended
inh'rrupt.

Alarm Interrupt
During each HTC
cycle. the HTC compan;s tlw hour minute, and
second registers w the corresponding alarm register. If the time and alarm registers match ;:ind if the A!£ hit is set !l). th!! alarm mterrupt; trig·p.-er& IIH)!B.

:;.

HeaHlnw Clock and CMOS RAM · Ha.rdw11re Description

Programming Example
The real-time dock (RTCI programming example demonstrates:
• Reading and writing the RTC registers and RAM
• Handling RTC interrupts
• interpreting the data stored in the RTC RAM
• Calculating the checksum that ensures data integrity
The next programming example provides the following routines;

rd rte
wr rte
rt.c cksum

Reads the indicated RTC register or RAM location
Vllrites the indicated RTC register or RAM location

btb

Returns tht~ binary equivalent of a binary-coded decimal
IBCDI value

bed

Returns the binary-coded decimal !BCD! equivalent of a
binary value
Reads the date-related registers and storell the results in
the indicated structure

Returns the calculated RTC RAM checksum

rd date

rd time

Reads the time-related registers and stores the results in
the indicated structure

shw date

Displays the current date at location 0,0

shw time

Displays the current time at loc1.1tion 0, 72

shw__ ddtyp

Displays the diskette drive types

shw __ hdtyp

Displays the hard disk drive types

rte int hand

Handles hardware interrupts from the RTC

shw hdw

Displays the hardware setup from RTC RAM

rte init

lnitialires the RTC intern1pt vector !70H) and the RTC
alarm registers

rte rest

Restores the RTC interrupt vector l70H) and disables clock
interrupts

rt.c

Provides menu selection of the examples and executes the
examples

Real·time Clock and CMOS RAM. · Programming Example

5- 15

CAUTION
i~Husr: the \, i\.Xinate· v-:i)fkstt1Uon tt~ tnrdfuncUon. 'f!v~ sr.ope of
tla:;: next
exan~.p1e i.{» Htnl1..,~:d tu tl:e context prn\'id.:::d ln d:i~~ J:L;;;. 1'1uaL NiJ nther use is !nt(:nded.

Constnnt V::tlues
~rh€ filF~ i !··=,~\id that

i;, .iucLudf:d ciefinr:s cons rant VH~ues fnr fGnr.tion
8 for iufor11nt.fr.n1 nbout

'Thf~ fl le ; exan:pft-'.h) that

St::'e

ts ~nc!r~d(;d defiucN t:he structure t~lJ.Jt:: tv! F~SS/\(t E ~:J1Eft
is t~sr~d to di.\pL1y the cv-~uu.

cp,tt;f ;.( y f·.n
;liltd\Vtff'!-~

reference function key conRtante ~;
;~ reference menu structure

#incl ud1J "'kvb, h 11
llin<:lude ''<'>xampla h"

I• daflna canatants uead in RTC example
ffd>?fine CKSUM .START OidO

#define CKSUM.END
1~

/• offset of

Ox20

e~art

offs<'1' of end

of cbecknum area */
of cbadcswn area "/

define ragioter A bit values ~;
·~

#define (fIP
#define DIV!DE.SEL

Ox80

#define HATLSEL

OxOd

FIXED VALIJE
Ha:rdwllce rela.ticd .,
P:rogr.a.nr<r".cr def tn:cd int-errn.pt :rate "i

Ox SO

j•

#define SET_UPD
llddlnc PIE
#d<!i'ine AlE
#d•Ji i.ne urn
#de.fine SQHE
#define Oi\,T :100
#dafin<'l CLY24

#define DSE

Ox20

0;".40
Ox 20
Ox10

Ox OS
Ox04
Ox02
O.xOi

update in progress bit •/

disable updating of date t time
/--i' P~rjodtc Tntexrupt E:n}\h.l~ -~:/
Ala:r:1t h1terrupt F.nable ' /
/•• Update Ended lut(H-rupt Enab1(1

Square Wa~P Enal>le
Data mode (BCD ~ 0. Binarc ~ 1) *'
l2·hnur clock• 0. 24 hour
1 ~,
i+

Dayl1ght SavinRB Ruabie •/

define reRister C bit values •/
#define TRQF
#de:!lne PIF
#define AIF
#define UIF

oxeo
O:x40

o.xzo
OxlO

/···
1~

[nJ.~n r.-u:r:it

R~quest

Fl ~p;

I* define reginter D bit valuea
#def inc~ VRT

Ox30

4· /

Pe1·l.ndic IntPrrupt Flag •/
1~ Alarm Interrupt Flag
/• Update-Ended FlaK

/• Valid Ram k Time bit

Rt•ahime Clock and C:VlOS RAM · Progrm.nmlng E::ium1p[e

Data Structures
The strudun:
HT(: defines the 1/0 space that acce'iscs the re;1l-time clock
The offset
the rcal-tirne clock IOOH-:U"Hi is written to <m 8-bit bi:rh that.
addrnsses the real· time c!nck, 'J his latch is lo<.·at1°d at L'O addn:;1'S 0070H. Data
is rend 01' wdt.ten through !10 ;ciddress 0071 ! r
Tht·' st.ructurn type CMOS defitws hcnv em:h HAJV! location is used within the
real- time tk>ck The real-time dock dedicates the first 14 i.ncaUoni; as
t>-,n:. Th'" remaining- fiO bytes of RAM nrc defined
to industry·
st-andard us:1~~e

The "!tructurc tvpe DATIJVI prnvides a consistent format for mi:wing date and
time informa.t,;m«

-; I

!" de,;lare structures used in RIC example

typedef atruct
{

uns.lg,ued chil.:r ad<h ,port;
unRigned char dat,,,port:

•• write RTC/CMOS addreRa to tbia port •/
/ ,, read/ wt: it·~ d.a i, ll. t.hrough thi Iii p(J rt ' /

RTC;
typedef struct
{

unsigned dun s~contls~
nrudgned char alr f~t""r
uru~igned char m:i nut es
unsigned drnr a1.r -~rr:in;
unaigned char hours ;
unsigned d1ar alr_hr:
\:tn~:igned

cha"\

dC~\11 '.

secnndH (0-59} current time •/
/-" aeccnds a1af'..'m.

*-/

/:t: minu-tes (0 69) current time :t-/
/~

minutes alarm */

hot1re (0-11/23) current time
I~
!~

hours alarm •/

day of-week (1-7)

•/

chat dom;
unsigned char month;
~1naign~d r:har yeHz- ~
11n:Ji11.ned drnr ,reg<1

;• day-of~mantb (1-28/29/30/31) ~1
/'f inonth (1 12) .-:un:ent date ;/

unH.ig:ned dv;r regh;.
unsigned drn.r rep,c

/·• r1egu.it1n· El '
regisLez C */
r~g:tst.Etr D ~ /
/::.: diagnostics byte "'·;

t::nsip;nt~d

/ ,, ?ear (0, 99) ,-:urrent. da~e "' 1
;
regi stier A 1!~

unsigned cha:r regd,
nntiJg_ned ChtlX d 1ag ~
llfH!ip;ned char reset ;
ddtyp;
u1rn)gn•d chat' rese:t-~~· 1

1;1w :i g<wd diar

char hdtyp;
unsl gnE•d char r(?ser\?2 ~
unstgn~-r3

5- 18

;· reason foT reRet
djskett.e drive type
/* res~r~ed byte
la ha1d disk type
I~ reserved byte

•/
t;

•/

unsigned char syscfg;
/* system configuration byte ~1
unsigned diar' bmeml:
/* base memory size low byte */
urns Lgned char bmemh;
I~ base memory size high byte
unsigneri char lcmeml;
/• expanaion memory size low byte •/
unsigned char lememh:
!• expanaion memory size high byte
unsigned char reaen<'l [Ox2e - 0:-:19];
;,, r<Jeern~d ''/
;,,, high byte of checksum (alwa.ye (J) "!
unaign<'!d char cksumh;
unsigned char cksuml;
/* low byte of checksum •/
;,,, expansion memory stze low byte "/
unsigned char hememl;
!• expansion memory size high byte •/
unsigned drnr hememh;
unsigned char cent.u:r_v;
/-t century byte of date (l9 from 1986)
I~ information flag ~;
unsigned char info;
unsigned cha'r reserv4[0x40 ,- Ox34]:
}

CMOS;

t;J"pedef si;ruct
{

int

!•

tHH.:onds:

minutes;
int hours;
int dow;
int dom;
lnt month;
int. year;

aecor~s

(0-59)

!• minutes (0-69) •/

jnt

/* hours (0-11/23) •/
/• day-of-week (1-7)
I• day-of-month (1-28/29/30/31) ~;

/* month

(1--,12) ~i

/• year (cent.u.ry '' 100 " year register} •/

} flATJM;

Real-time Cloek mid CMOS RAM

Programming E:rnmplu

Reading the Registers and RAM
off;;<c~t

r iYrnre n! the dM<l

r~ffsr~t

faJ.lg \VithJn thi.s rfing\:. th.e rctld

rt the

prng:rPss btc.

/·-"'*·-l'
/ ~"

.f-~-+

.+.

rd~rtc (}

;_nt- r:d ___ -rtc (oIJs~t)

{

!HG ;'p:ttc;
G~OS *_pc:r.ns;
umngned ir,r; int.r. f:lg
nnsi gn$d (:b-,;,1:r xet vaJ;

!,~

p1.~ to ~onresg & date porta
/;• ptr tQ ?.TC/CMOS struc:ture

val~e ~o

->/

CPU IF stat;e */
return

jt aes.ign 1/0 ~ddress .. ,
~tructure

0tfa~t

is zero

while~)_·:

jntr_.flg ~ int __ off();
(_~J.tp

/t nc~ it:terrupt~ ~:loweci ~;
/X s0t to r~g A zj
;~

el;.ii:~ 1ntr .. :f~·.g ~T 'int __ off(~;
cutp(Bp:rt·-:- >;~ddr __ p~;rt. ;;)!'f::e-t·.) ~

i·:

!-~

Bel to

~-/

aLl0wed

intsrr~pts

:".'c-t.va1 ,... -Ln_r (&prtc->d:f1-~ a .. p01;t) ;

i gt~- r:;D ( i.t1.t:r.~ f :tF1.

-r-e-tu:r-n (1·et··nil) :

test IJlP bi.t

d~sjred

uffset *f
:.read da:ta ~,,,.

aJ.}o~
ntcrrupta t/
ieturn data byt~ ~1

\Vriting the Registers and RAM
The funct.ion uT rte writes the indicated bvte of real-time clock HAM. Before
accessing the byFe. the offaet is cornpnrud. to the range OOH·OHH. This is the
offset rnngc of the data registers, whkh are invalid during update cycles. If thti
utfst>t falls within this nrng·c. t.he write is synchrnnized with the update-inprogress bit.

/•> wr-..rtc 0 - w:rlte a.n RTC byt"

•·/

l··~**~~*·~·t~~~~*~~y~~~~*****~~·

$k*~~~**~***~*•****~****~-~~~i*~~~~~¥~·*1

/·• write R.TC byte >/

void wr. rtc(o:ffaet, niJue)
int offset;
nn.sJgned char value,

/• offset to write •/

I., byte value to wr.ite "'I

{

!• ptr to address & data port• a/

RTC *prtc;
~pcmus;

CMOS

/, ptr to !lTC/CMOS st.ructure -i./
I~

unaigned int i ntt: _f lg;

prtc

(RTC •)Ox70;

pc:nuB

if(offaet < (int)(tpcmoa->rega))

CPU IF state •/

I* assign I/O address •/
/* structure offset is zero •/
!~

need to monitor UlP ? •I

{

while(l)

/•' break out when :ready

{

int:r_flg - int_offO;

01rtp(&prtc->addr_port, &pcmos->rega)
tf(inp(&prtc->data_ port) k UJP}
int .. on ( 1ntr __ t l.g} ;

uo Jnten:upts allow<'d •/
/« set tn reg A •/
/« test UIP bit •/

I•" allow inte:r:i:·upts "'/

<>lse breaK;
}
}

el•e intr_flg

lot_off().
offaet):
outp(&prtc->data_port, value),
int .. on(intr_flg}:

outp(&prtc->addr_~ort.

1• no interrupts allowed •/
/• set to desired of feet •/

!• write data •/
/* ailow inter:nipta -"/

}

R«altim" Cfod;: mid C1\10S RAM " Progrmnming Ex.nmple

5- 21

Cnlculating the Checksun1
The ftm<_·tinn rte cksum odculHtes the checksum and returns the result to Hie
caller. The ched{~1m1 if! the ;,um, rnndulo 2fi(i, of all bytes in tho ninge
CKSlJM
through CKSUtv!_ENIJ.

caln.:.Jate t.he CMOS ched:sum and return it::; ·•:.lni;

unsig1wtl char rh:_d•:nuxn()

/·• •:aku:late th<' CMOS ch.,cksurn

,
'·

int i:
una igned ~: ha:r surn;

eum

for(i ·~ CKSIJM_START; i
sum "" rd_rtr: 0) ;

rwturn (tHJrrJ :
}

/>"

-:~ CKSUM_Elm:

i' ")

/i loop control ~;
the c::hecksum *-/

acc1Jrr;Hla.ter,1

sum starts out zero •!
/* all checksum byten •

/•< read data and add to sum ·'/
/·I• return caJcolatf'd checksum "'/

Converting Binary-Coded Data
The ROM BIOS defines the <lat<J mode as binary-coded dccimat \BCD) and
therefore, su does this c.xample. This requirefi converting between BCO irnd
binary. The function l!tb converts a BCD vnlue to its binary equivalent.. The
function bed converts a binary value to it.s BCD cquivalenL

btb(bcd_ val)

.!"' bed to binary integtn '";'

{

/K aasuma valid bed valua
teturn ( ((bed.val >> 4) ,

10)

(bed_ val &: Oo:Of));

}

/* bed

:-"/

convert binary value to bed value

unsigned char bcd(val)

unsigned char val;
{

binary to bed •/

/• binary value

/y aeaume valid bed value

uns i.gned <:hu. tmp;

tmp n (val / 10) << 4;
tmp '~ val 1, IO;
return{tmp);

/-- t;nns in npper nibble /
ones in lower nibble s/
;~, return BCD val11e

Real-time Clock and CMOS RAM - Programming Ex<1mple

Heading the
and swn:s the
paranH::ter, It ean h<'

The function rd dme reads aU of the dn! r> rdau:d
1e;mlr,:; :n the DA'I'Jl\/1 structure pointed rn by the
ca!ied at any ti1ne withuut n~strktkin.
is not :1 real-time dock
location thn t nvercorne~
must be upd21ted rnarmaHy or by softwure.

The century byte i« an
It

/-t, read the d!'lt<" •!

•:oi.d rd_dat e

.·'

\.;h~re

to sti:--).t·e data ;,/

{

}

pd->d.ow

htb (rr.:t.r1:c (&pcmt:-a ·<':·dow)) ~

pd~>d.or;,

btb(rrt_rtc(ipcmoe-~da~J)

pd->c;m1th

btb(rci_rtc{&pcmos-~~lonth)):

pd- >)1 €l!tl

btb(rd_rtc

pd->·yP.a.r

btb(rd_rtc(&p~mos->y·ca1)),

100;

da~"·-nf

w~ek ~/

day-af ·montb ~;
/-:c· month -';/
ci;.:ntur:~~

·\~,.

Rending the 'l'ime
Th~ fum.•tion

rd time reads 11Il ol t:h(;' tin1e-rehited
result$ in tht: n/\TIM ;;LructUH' pointed tn by the
tion ;Jssmnes the tis1· or the z,J.hour dock mode. It
>.-~: i rhtxirt. res tr ~ct,i.on.

and ''tore1> the
parnmer.ec This i1.mr><:~iUed at rrny tirne

read thR tim~

•I

/1 where to store data

DATlM ••pd;

pz:mos ":,;; O;
pd .>second..$

/* ~tru.cture offset is zero ~!

btb(rJ_rtc(kpcmos >3~cnn~e)J:
pd~->Ffinutes - btb(rd_rtc(&pcmas->minutee)):
pd ~>'bour-~1
btb(1d_rtc(kpcmoa->hoq1N));

seconds ,._ /
mt.nut~~

RBal-time Clm:k and CMOS RAM - Programming Exampk1

hour-f;

<'<'/

Displaying the Date
Tht< function sine date

at row 0 and column

the current dat(!
without restrldknt.

dPfine Rome day and month 1taroes

char d.ay_n~.m~f.8] f10]
{
Hill"l~li.d_ll

"Sund a f ~~

char mon1,h_namf: Ll31 [WJ {
11

/-1:~

Inval:td· 1 ,

~'Jf:tnaa.rvq

Hf'ebrua.1')"n.

HMay·H

~!Septe~ber''.

''October''

eh~~date

Jn_nf!i;~ 1

~how

date

11 Ma.t•::.bn
''

Jnl:(~

nAug_1J~t.~·,

''Novemb~r·· 1

startin~

date a1;d time
i*

:t~~9s }~99 ~~:~rl,

%04di'

~mofith_name(dt ~nr1th.)f-O].

disp_st~{O,

~; fh::~c~mb~'-:r 11

at 70~ 0 colwnn 0

iJ.l\TlM dt:
char sdut«:cfbO];

epr:intf(sda.t~

rt,_": is

Apr:i l ~~,

~1t-ruct.ure

place tu Bture 01J·tp1lf;

~\.1ay __ na.n:~tdt rh;;_,1j f.0J 1
dt doT, dt y~ar);

a. sctat~):

" display it

}

Real-ti.me Clock und CMOS RAM

Exmnple

-"'-./
~

Dis1llaying the Time
The ftmction shw time displays the current time starting at row 0 ond column
7~~- lt nm bo c;,JJ,;i at ;rny tit;lt' without restrlctlon.
;

"--. --·:C'"".
-""> '~:

/" shw .. t irne

show time on r-ow 0 column (last_column - 7)

sh.i_timeO
{
DA TIM dt;

char atime[SO];

I• date and time structure -./
/« pla<::e t(l store output -</

/ ' read current time •/
"'A.2d:%02d:,,02d';, dt.lwurs, dt.minutes, dt.secondi>);
disp_.atr(O, 72, ,time);
/~display it*/
rd_.time(kdt);

~•p.rinLf{st,ime,

}

Real time Clm~k and CMOS RAM. · Programming Ei;.amplc

Displaving
the
.._,
~.

Drive
c;;;lkd by thro

tiisk~tte

exiv~

dt.-~.;~

;

np.t 1ri_tf
h.r•?:~"".k;

~:yp~

·t~t:tf'r

48 tpi ri~J~

Displaying the Hard Disk Type
The function .-.h"" hdlyp is a te~J: form.ritt.ing subniutirn~ that. gencmtes tlw h~ird
disk drive tvpe ;H:;·ordlng to the
parameters. H is
calied
thr:•
tun,:Uon slr;v hrhv

1~
~":ha..r-

show hard dis~ type

disk type

*pc;

cb ;,.:t hdt f pi

t~erd

cha:t: d:ri "Ve:

dri·:12 l<>tt<:>r

int i;
aprintI(pr

''Hard dj.sk riri~e %c

i.B

11 ,

dri~e)

if (hdtyp) '•print f (&pc r i 1. "type '.',d"' hd\;yp)

else aprinti(&pc[i].

1 fnon~ex1si.cnt

/.'- dri.~".-tf!
-1:

t_v·pf-5 '"':

no d.ri .,,.f4:

lfondling the Clock Interrupts
The function rte int hand is the real.time dock interrnpt lrnndler lt checks for
all 1•f the three 11'1s.,if1le interrupts. update-·endcd flag Hll FL alarm
tAF1.
11nd periodk
flag lP!FI After handling the internipts. the inwrrupt.
hand!er notifies tlw internipt <:nntro!ler.
The upd:ne·ended in1Yrru.pt occurs OH(<' per seconcL i\t each interrupt the interrupt han.dler incn~ments
gioba! fi«f!. time
tn indicate that at lr:as1
one second has elapsed.
·

'The ~1h:1rnl interrupt ls initialized to the first se:cnnd of e--~,~ery
rupi. the ]nterrupt h.ondler hv.-:t'IJ:Blf'-nts the
fla~~ 1 date
that at least one

/\i. na~b .int-er~

tu ind:cate

hn<>

The periodic interrupt is initialized to ;-J nite of 1:25 ms. At <'1.tt:h
the
h~1.ndJf:r inere1ne·nt:s the global con.nteL rnetri.H1on1e. ·rhe B~~h"i t~rncr
cxnniplc in
i.l us.:s this counter for output ti.ming. Abe._
the periodic
handler call£
If required, unbcep turns off the
bc!i lbeep <>01mdL 'I'bc
prngrums use the
lo g'Pncnite a hdl

R!>11H.lme Clock ;\ml CMOS RAM · PmgnmJmlog

/< rte int.hand() ·· real-time clock interrupt handler

I* 1 second update flag
!• 1 day update flag •/

int time. flag;

int date .. flag;
unBigned int metrornime,
jnt 11'.otor_Jlag;
int head_!i<ettle;

I,, t. imer i ox.· sound outpu i; • /
tjm<Jr for disket·te d1·ive moton' "-)

/* bead aettlft tiner for diskette drives

void rtc_int_hand()
{

CMOS

/o; ptr to RTC/CMOS atructtin' ~/
I• ter·cr• to .n':ad in :r,eg C "/

•kpCl"!<Hc\ :

uns:i gned <~h.ar tmp;
pcrn,.ne, :.- -:; 0;

tmp • rd.rtc(kpcmoa->regc);

I• structure offset iR zero •/
1:ead current interrupt requents »/

:if(tmp & llff) time ila)I;++;
• time updatea once per second ~1
if(t:np & AIF) date .flag+t, /•· aJarn1 set for once per day at 00:00:00 */
if(tmp k PI!'l
I~ peiiodic intBrrupt ? ~1
{

met rouom(t-t· t;
unbeepO,
i f (motor. flag)
i f ( · -mot(>:r_ flag
motar_off 0 :
i:f (head_ settle)
head .scttlP·-;

I·• increment timing for speaker df,mo ,,/
/" unbeep turns off speaker if bell t/
/w 1f timing diskette drive motors •/
1~ if timed out •/
!• call routine to turn motors off •/
1~ if timing head settle •/
/ :+:

:reduce \ount t/

}

eoi(1);

/·' end of interrupt for inl>l'rrupt con'tl:oll<er '-/

}

Real-time Clock and Cl\HlS RAM · Prognrniruing Ex!ll11j}lt~

Interpreting the RA:M Contents
The funet!n:n sln~:.~ hdrc ~.nte-rrn et.s t-hi:~
1oct-1t;ions Jn the realthn.:• clor:k HAM :md
ti.•<' t/O:>uli ><. The ROJV! BiOS
this data

~h )1d--..1()

/:"'

shr,:,v

hax-d~are

(~t~~os

set.up lH

/*~~**~~~=~~*~k*~~~~~~+~•~•*~*~~

t~~,~~~*~~~~~8~{~~*~*~~x~**~*4+~**~t

unsifo;ued cha!_· tmp,
Ullbi~n<--d

f.,

int '-_;;i.

to J~_f:}ld CMDB byt.e r~:"id
/ ;.- to ho td m.~rr.or:y Gi-',:e -;,

/* ptr to RTC/GMOS

CMOS *TKlnCii:

str·uctur~

cha1 "i""':
{:;ha:r line [b J 21 ;
-~rd.~-d inc

r..uu 1fJ

ttd~fin0

COL t7

pcmn~

:::- 0;

trr-~p

:rd_rtcLtpcrno,t.<--~syBLJ-?) i

;_j

/·r-

eprintf(lir1e t'%d diskett~ dri.v~(s)
dJup_atr(RDU, CO~. line);

ryffe~ti is zero */
/"* rr•tvl ay:;1,t;em ;;;:4'H1.fJ.g ,~-/

s.t:ructur~

present'~.

(tn:p >> 6) + 1)

t Ox30l >~ 4}

switch(

check video type */

{
!~

case 0:

nnt a vali<l type *I

p!: ~ ''}nva.li~ v~deo typci 1 l
ln<e<Ji;:

' 1 Monoc:hro1•~

adapter

~ith

zlarallcJ

cort--~

~-'.":2"~"1.k:

GDL, pc);

;s r•ad

di~plffy

djoie~te

type

drlve t)pes

~ideo

sbw_ddtyp(line, tmµ

4, 'A'I;

<!':

t~p

tmn >>

·~..

''G');

cmp •

rd_rtc(kpcmos-,b~e~l),
J.flBi~;nZ"d

;;:..{

vpriat-f(l:n{~di.a11_.~tr{ROW

tmp -

<"'~

&. ClJT,

:::o:.

%dK bytJ?s 1; , u.t}·

line):

~d_rtc(&pcmos-~~effi~~h).

diBplay base memory

/:r. expanded

r;~emcrry

high. byte

jK ehlft and

t.·•·p
ni l

11i -~

t.:no

aeeig~

i ·•· expanded m<'mory low byte "/

/* add 1.o~ by·te

( 1msigned int) trr.p:

Rp!intf(li.ne, ''Expansion ~emorv
diap_str(ROW + G. COL, li.ne);
trnp

·•

ini;)tnp;

Hfhu~e TerrrnTy

i;;

d·iaplay dri~e c type ~!
/~ get drive d type ~;
1~ display d~i.ve d typ~ 4/
/1 base memory l1igh byt~ */
Ahift acd agsi.gn ~1
Ji· base memory 1.ow byte */

"'bn:_emh):

ir:1)t.;;:p

t.ype ~ /

(-~uJBi~ned

i.'.l

:* re~d h~rrl d:is~ type~ •/
f». get dri~e ~ type ~'

d:i HjJ .. •·d, r (N.tni ~ 4' COL
Jin~) ;
sh-.v_~hdtyp(1inc
tmp & O.~:OJ, 'D~):
d1Hp r~tr(H.Ch,,: + Gr GOI., 1in~)
u;._...:.

d.ri.\re

diepl,,_y d~:rive b tvi~~ :,,.,..

= xd_rtc(&pc~os-:>hdty·p);

n·h;,-.i_Jtdtypfl ine,

~et

/* dJspl(iy d:.ci·;te a typ€
fi- get dri,•e 6 t}pe

dlsp ..,Htr(H.QW t 2, CDt, ljne),
shw _ t~dt YP· ( 1 i :nc t:r:p & c-)xOf, ; H ., } ,
diBp __ c~r(R~W + 3, COL, Ji.ne):

-c-.

~/dctr:

rrl :ttc: (&-pC!'-'l_{~n·-·-"iohemP>td:d;
i.nt-}t~p << 8:
rd _.r t.c. (&pc!:,os-~~;-he.!~x~;nl):

u-i) ;
diapJay

e~panded memnry +/
ez:pand€d m~n:ory- hj gh byte f /

ahift and assi~o
iow bvte s/

e~panded ~emorv
!~

Jnt)tmp;

111

Hprl~tf{Jin~.

''Expansion men1or
disµ_atr{RDW • 1, CUL. lioe):

%dE

byt~a ~~,

byt.~~~!· 1
I~

b~te

memory

add law

~ii)

displ.ny

e~panded

He1.1!-t.imr Clock and CMOS HA.M · J.'rngrainming Ex.ample

lnitiolizing t.he Real·

C!ock

fJ!sf:'lbie•; t'{\~.d-ti;~ut"~ C'.f?<:

Jr.d:en~~1p:t.s r~nd

•

ln.:dalf?-i'~G
nlarn~
ll

update

'.::h..;:;: pt('~-.:~_':~J<H)r lnLt~r1
and t.I.nc:1bsks
in iDrP.~ pts

t.h(~ n·-~:.:Jt-tinic el:·)ck ('.~_1nt.coL a~1d

controller

} i

RTC/CMOS ottu~turc

/Y ptr to

wT __ Ttc(&p~:m~a-:~regb,

SET_UE'D

fYtepar~ t.:J

·l ·~·

j_ ?:i-L (0-?~!G) ;

D!Vl~E

9EL

RATE~_Sl':L) ~

s~t
1~

•:,;r_.rtc~f&.pcr-t:Y'.!' ::·~L'..:-:- ~mtn,

0Y00);

~r_.~t~:(&pca10~->~!c

0x00)

~sc.

Arr: l UJf

~Tit~

v~~tcr

Jnitialize RTC i.nterrupt

~r- __ rtc{&pcmcs->tega.

·,,.or ___ J:t~= {!pcr~~r.1fi"''>:!'.,e_gb

in.it \,/

dj9ahle PfC !.atPrr~pt

i.:nask ( 1 _ :J. «'!-) :

p::.

bDllTB

Ya:.te

-.-/

alar~

w1·itP reinutPB A.larm t/
:P TE

1)'

Ru1Himc Clock an•l CMOS R;\M -

Restoring the Interrupt Vectors
To shut down real·t.ime clock int<:rn1pt processing, the rte n>,q functiow
"
•
•

DisablE>s the rnaI·time dock interrupts
Masks the interrupt controllr"r input
Heswres thf' interrupt \'Cdor to its previous conditkm

Non;
tfpdat•:
clock st.ops,

art. disahlcd 1 !~he

rPmHin enablefL If L!pdate

.... ,;'

.rtc~reat ()

{

CMOS

!• ptr to RTC/CMDS structure •/

'i'p<:Jr11)s,

pcmos ,;,,, O;

wr. _ rt.("{k:pcmon">rep;b, CJ_.1<24)"

imas~>;_(t,

O},

iv __ retst(Ox70);

structilre nffnet is zert> ~-!
disable ~lock int~rrupts
1~

diRable PIC

int~rrupt

iestorc intecrupt vector

ReaHJm(' Cloek and CMOS RAM - Programming Example

!l- 35

Real-Time Clock

,.
'

s
{;

{
i"

Di~:pla_,r

t'.~nf;

hat'd.,..~~.:r~

Uisp1.a~

CMflR

chec~s~~n'~

:v:~t~;.~/~

}

; ,

f.
(i

f ·'- !
\)

dny·o;f

·~(l,

H;~7

S-:::'."~

H?~.~)

R~t_,>J:~::

(;I

o.Jc::;,li; 0

to ft.n.in :tner.-u 1;

} .

;

tu itold GMO~ byte ~e5d
hold ~-alc~J-~ted c~~c~H,1m ~,
,r~
t~

}":i;.:rfd.)d

l:i.~Y

·....-h_-.'._J e f 1)
~J:t 8p.wr.-~~;;'\_,i {if'.£"7~(5iµi t=:::h{ l.!.!1C-: r· =

ltold

~.tlltl
~~1111

input

lin~

u~l~ctioi~

·Lo utore d~t~ ~ t~.1ue ~;
pt• ·tu RtG!C~OG 8tru(·~.J!e ;:!

~l.a~~

~aae

.F2:

sp:rinLf(1 int~

·ic:e11£t~

,:hec1~.mJm

Gpri.n~f(linB.

''Calculat~d che':~s~m

disr .. etclR(~~.

C~l ..

ij_ne),

~r rt~(&p~~0s-->~t:~~ml,
Bp:rintf(l:in~~

1 ' 0:t~e

EuE);

;j:"eu_;~~

di.ep_ . Btr{R~~, COL

byt..,.,,,

~H"'r:.

t.o

7:o~:i~"..ti1",

su.--r;J;

li11c1.

't:n:-.~:·sk;

COL.·'.~_;:Dtc::-

,_._ , CBt,

;'~ 1 h(·re

\,'.1_;~~.

n~ht.c-r~

"'.;,

rlB~s-

aa MM/r:r;/fY'<t"'=····

~-f'ft rep:rO-rJf!J:tB

';.;h.=f:< !Gf~Y-1 t-.h
(1
DD lr.p:rf~B-e_p:,a tf~.-e day (1

) ,

I~. i i,--)f ,,. o_:rt,1 ~ !-~~]~

€~ ·~ _ key ;·i (H~JW

,..

W:t'

;:tt~{kp~ri!Cfi

>~":Gtd;b,

lJ\t

:ri:·c <a:p<:~;-~0s·->do.r1.;
~ye3r.

f!-~:d.(d.t

n.-~,:;t·t; ·

i1t':~--: 1 th)) ~

t.cd~d.t. fir;:-J))

b<d(dt y~a~ % 10~})
l""=d {d~.. y-e.:;i 1:· / ton)}

>-·=~r:t?tr\·,

* set ne~ tim~ t /

di<!p_str HOH
rlisp ... s~r ROW~
get

PJW

~ey8

~~;;(;~_nf\.li:ttrB,

Lf (r

~))

CUI..

4. crit

i 1 Tim~:
j·

11 )

6, line),

:' 1'.-~2d:%:ld.:Y~2d'~,

&.Ut lu;q':;s, &dr, 1 ninuL~8 1

~-:ontinu4:'.;

}
~r._r~c(tp~~0~·->i:ourz.

b~d(dt.bo11ra));

bcd<.dt .minute£t,~
/~

rd. rtc{tpcmo~->re~dl;
sh" tir.,;;(,::

!• make

~ime

s~conds

vaJ.id, set tbe YRT i>i~

writ~

d1sp _~1e£!.J (rrr-c!.:)

t.r-t:aL;

raue F7:
whi tefl)
di~p_s~r(R0W,

COL

!!Er1t·er da3·-0f-week (1

7) '.

g~t_l-:.. 0_'.tt~(RO~.
T

i: d_

l;UL + 27; Ji:tt<-'.'·);
11 %d!i,
~ aeranf(line
&dt.dow):

rt~~ (~rcr..c-s

?hv,; __ da 1-e ().,
d:ir;p_ryenu(mrt~) ·
hrc~k;

!~~et

u functio11 key for ~eru Belectj_on ··/

Chapter 6
Three-Channel Counter
and Speaker
()vervie\V
The VAX.mate processnr board has an B254 programmable interval timer th;u
pruvides thrne independent 113-htt 1.·ounters for crnmtieg or timing. All three
cmmt0rn have a 1. l. 9:i l 816 !'vlHz cliwk input. The counters are progTamnrnble

and f:!fe used by the HOM BIOS as follows:
•

Cm.inter 0 fB a gonerol purpose timer to provide:
1\ time·nf~cfoy dock
;\ diskette drive motor timer
A screen blanking tirrwr

Its outpnt goes to IHQO nf the interrupt logic.
CAUTION: R.eprogramming thh com1ter cnn destroy the timirig.

Co1rnf:e1· l provides rhe dynamic RAM refresh timing. The RO!Vl BIOS
programs fr for a l JJS
time. Its output is connected to the refresh
count.er.
GA.UT.ION: Reprogramming thh !'ounter can desrroy the refresh
•

(,o;mter 2 provides a freq1wncy·rnodulat·ed square wave output. for thG
interfoce.

Additional Source of Information
Tht· !ollowing· Intel Corporation docurm•nt pro\'irles additional Information c.n

i:hn 8254 three-channel counter/timer.

Thr1'e-Cb1mnel Cmwter nnd Siwakcr - Hnrdware Description

~t:-im~;.!

D;.;ra

r_,,f

C1k 0

lJo.y Cleek

Bu·c '----

;~~cfr;osh

G1k 1

Cr irntn~
Oht ~~·

{.Re:

r::ounter lJescri

ck~·::!rS :.b_t~ nth~1~
i:t"l .~,~hit :-,r:unt h1 th~·::

LSH <·_;_~~urs t'.[u·:~ !vfSB ~1.cct

Trw ,~lgrnil:;; CLK. GATE, and OUT are all connected to control logic on the
U't' module. A..lA.:-l181R lvlHz signal divided
l2 prnvides a J.1931.RIG MHz
dock to all three •:mrntf~rs.

;\ high level \U at the GATE input enables counting and a lov1' level \Ol at the
GATE input disables Cllunting:.
Table f>-1 show" the CIA<. input frequeiwy, the GATE smn·ce, and the deNHna
tion uf tlw OUT
Tah!P {\.!

Counti:•r Signul~

Cmmt('1'

CLK Frequency

GATE Source

OUI DcsH1u11.!on

l.Hl:H8.!G 1\Uh

Tied higt1
Tied high

rn<cio

System CSR i.bit Oi

Sp~:akcr driver

MHz
l. l 9 3 18 t ii M. f i z

U~}aUHG

Refresh timer

IV1ode Definitions
TbP three-rhmmel cnunteritimer has six modes of opernti.on:
M.ndc 0
Mrnfo 1

Jnterrnpt on Terminal Connt
Hardware Retdggernhle One,Shot \not used\

l\lnd0 2

Ifate Grmerntm.'

~.il(Xfo

;3
:i.•tode 4

SQuarn \<Vav':; Modi:'

Software

Strobe

_I\t odt~ :~)

}lardware

Strobe (retr.iggerablPl

Table 6·2 .lists th<'· ri1:'fm1!t rn.odre ;:ind function of cadi counter in tlw~ V/\Xrrrnte
workstiitinn ws t•stpblisliud by the HOM BIOS).

Table 13-2
r~.:1_:.t~nter

M.odes Used by the Three Counter~
F"-1nction

1V!octe

dock

De:<cri ptio1 J

Output

l!nrdw£ire

gored strobe

Hot:e generator

Hefresb timing
2

wavcfor.m.

.Refresh counter

Squan' wave

Three-Channd Counter and Spei1ker

Hu.rdwnre Description

'.I

l\'lod.e 0 (Interrupt on Terminal CounU
M.odc 0 is u'ied for one·shot. event

Initializing Mode 0
Programming the conixol word for mode 0 c<iu-;eq OUT to go low. The O.A'I'F
inpu1. iws no dfoct nn th•' OlJ'f ':ligna!.
lf <i ne•.v count. h written
counting. the new count i'I loaded on the next
CLK pulse m1d cmmtlng· continue;; from tlw new count.

Mode 0 Cycle
\Vriting u new count starts the
'Where n equals the count. the mode 0
cycle is n _;. l CLK pulses long. Dmi.ng; tfo:! start of tlrn
the OUT sigrwl
is iow tor n CLE. pt.dses 1whi!e the cmmtcr decrement~ from n to O..; On t.he
next CLE
the OUT sJgmJ.l makes a transition frorn low·tu·high. The OUT
unOI the control W(>n.l. is written or until a 11e1•i cnvnt l:'l

Mode J (Hardware Retriggerable One·Shotl
l'vtude 1 is w;cd tr.a· one·sbot evr:nt. counting. i:h::cmlse the GATE input !s the
trigger. mode
is vi.nhle
nn counter 2 {t!w GA.TE: input of r2rnmt.<"rs H and
1 art: t.lcd
M.ode l could he used for sound generatl.rm. but it: !s not norn1rdly used Cd.1 i:l'u!- \-".-~\X:.:-n11t~ yvorkstation.

Initializing Mode ]
ProgTarnrning t.lw control word fnr modr:

OUT tn go high ;md mm" the

and
a ne-..v cnunt cau<;•)H
The GATE: input }urn no effect. rn1 the

OUT

'\.Vriting a new count during ccmnting hRs no effect on the t•mrent count.
Howc'.'er. [f the G:\TE input ts triggen>i.l the eye.le resfaut,; with the new count
Mod~~

\.Yitb the
arrnecL a lnv,:to-hlgh iran,,!tkm at the Oi\1'E inpot n1uG'"''"
the cn:le Cln the nee;;. CLh pnl.se, the count is loadt<d anrl tlw OUT sigmil
1nak.es a
t.r~H1Sition. \lVhPre Jl eqt~_als the Ci-1Urrt, the CH_J"f signal rornnins low for n CLf\
That is, when the cnrmt decrements t.o 0, 1Jw
OUT siglia' gPes
'f'hu~. after a cuun~

ha_s dt:crernf:ntefi to 0.
The co1mt i<> reloaded

automatically.
Triggering the GAT1'~ input bl'fore a count decrements to 0 restarts the
on the next C·LK pulse. The count i« reloaded autonrnti.cally. He•,ause the~ coimL
did not
the OUT signul remains low.

l\Iode 2 (Rate Generator)
\Nhere n equals the initial count, mode 2 functions like a dh·ide by 11 counter,
rr genmates pulses at a rate equal to the inpllt (r.>q1w11cy divided by the initicil
emint tn). Mode 2 is periodic. repeating the cycle t•very 11 CL.K pulses.
The ROM BJOS uses count•~r I. in mode 2 t.v provide the refresh tiJning signaL

Initializing Mode 2
Progrnmming the wntrul word for mude 2 causes OUT to go high. Providing·
that the GATE input is high. the cydP st<irts l CLK pulse aft.er the initial
count ls written.
H the OATE input goes low, the OUT sigrwl goes high immediately. On the
CU{ pulst> following a low-tu-high transition at the GATE input, t.he counter
relomfa the initi.a! count Thus. the GATE input can synchronize the count tn
an external event.
'VVriting a 1ww count during 1:ountin1" has no effect on the count for tbc cnrrent
cy<:le. When the cycle repeats, the 0.111.nt is reloaded wit.h the new count.
l-Jov,:evcr. if th<" GATE input is triggered, the new C(•1mt is loaded on the next
CLK pulse and
rnstarts.

Mode 2 Cycle
Where 11 is the initial eonnt . the mode 2 cyell'J is 11 CLK pulses long. During
the start of the cycle, the OIJT signal is high. The OUT signal remains h.igh
until the <'ount decrements to l. When the count. def'.remcnt.s to 1.. the OUT
signal nwkes a high-to-low trnnsitiun and t.he counter reloads the initbl eounL
The OUT signal is low only for that CLK pulse. On the nexl' CU< pulse. the
OUT signal goes
and the
repeats.

NOTE
ln mode 2. a count nf 1 is invnlirl.

1\'Iode a (Square \\!ave Mode)
ll.·fode :.l genernte;; a squarn wave at the OUT signal. \\'herf' '' is the count. the
Ot'T signal has a frequency equal to CLK / n When n is an oven number, the
OlJT sigiwl is high for n I 2 CLK pulses and then I.ow for n i 2 CLK pulses
When n !;;; <lll odd number. the 0 UT '<i.gnal is high for 1n + l) ; :3 CL K pulses
and th0n low fot \ n
!I ,· 2 CLK
Thrue·Channel Cnunt<>v and Spcnker ·· Hardware Description

G~ !i

rvfodi: :s
t-h'l: 1_:outr0l '~vnrd for .rn(H:{e :3 CtHJSes ()l)rT to go high . Pn_H.~idh:g

that thf; (~/VrE
count ls -v.:ritt>f:~n-

the

starts

clock puh.:o ~dter the iuitial

lf the (¥1\TE input. goes low, the OUT signal ,P;oes high
On :he
('LE
fol!m;;inf.;: a low·i.•)·hlgb transition at the (;,'\TE input, tbe counter
rdoEJds the initial. count. Thus, the: GATE 1rip•..tt can synchn;oni:;::(;' tlw count to
;m eKternai event.

v\'rlUng a ne>\' count. during
\.~/hc:-n

tbe

has no effect PE the cnunt for :he current

repf:;1ts, the r·:fHJnt is teloaded vvit.h tbc ne1.Y counc

lfowever. if the GATE input is

the new cnnnt is looded on the next

Mode :~ Cyde
ln the fir'lt CLK puhiP., the initi.a! crnmt is kiach•cL lt the count is odd, Own
count · 1 iH l«nrfocL 'The'
stans with the next CU\
clr.1nt decrf~n1Bnt.s b..J O~ the initi.:d cnunr. !~ tf::3t_.-r_:d fn:r an ode.! or even vabae_ lf
the i:ntti.rd count 1.VU:S• e·\:cn; the ()lFI" signal rn:tkf~~,,. Bil irnrnediatf~ trnn:?:iition fro1n

If thf'. initiDJ c~;,tH~t \N.a_s fKht t.ht: countrT 1-V3;,ts one rnoru ( Lf{ pulse
<.ind tben rnnke~~ ;;
tc·~loiv tran-sith:~n. 'fhe initrai couni i::; reloarJcd Hr1d tiec·
1

th~: ceunt is fh:.crf~rnented by b,.vn_ \Vhen the count defTPHH?rtt'\
t hf; ()l?f 8ig·nr1J lnDkes an irrnne-dinte trnns.ition fn~rn
the in=
it.lat count i}:-. r..:;inad.Pd a.nd dec!:-i::::~nen.t~~d
tv\'o. \~0 hh:h

(:LH.

ttj (L

Triggered Sbohc)

ode 4
In :node ·1. the ceunt
the initiJ~. counr. the <JtIT
pulse and thr:-n

until ~~ nev,: count is \Vrt.tten.

Jnitittlh:ing '.\fodt' 4
the uJncriA yvord f(ff rnode d C.'.:HJses ()lT_f bJ< f~{t)
input has no (~ffr:f.:L c,x_1. rltt· CH !1'

CLi\ pulse ;rnd ('OLmting •:ontinues from the 1ww ccamt.
F'oJ '"}
'~.01.n.1t, v.,, ritin~~· the fin~t bvr:e t1as PJ) ttffect tHt
Second b:-r·te all~.--~;,;;,; S tlu::~ i.'{Jllllt t-O be lufHled Ort the flf':Xt
>1 new coun: v•hi\e t.ht0

to be k~ach~d €)D the JH-<:Xt (~ i JS:

count J~

\\'ridng the

Mode 4 Cycle
T!w ni(•dP 4
[~ trigg-ert!d hy
a new r'.ount. The new cotmt is londed
on th<" next CL!\. pulse. bnt not decrmnentcd. With each s1wcessivc CLI\ puls<:'.
tht· count is defTenwnted. \Vhen the count dPc:rcments t.o 0, the OUT signal
goes low. !t. rnmains !oy;; for 1 CLK pulsf'. \Vhen the count; deerernent.s to
FFFFtL the OU'r signal goes high. Until a new <x•unt is written, the OUT
rNnains.
which n!st;;1rts the c:vclc.

!\:lode fi 0-Iarchvare Trigg·ered Strobe)
Beni\lse the G:\TE input is the

, mode f> is viable only on counter 2 It.he
of •:otmters 0 and J nre tied high.} Where 11 eqm•ls the initial
C<J\1flf:. t!l('. Ol n·
for /1 .+ 1 CL!{ pulses. l()W for J CLK µulse,
and tiwn
iuput trlgg;ers nnother

(L\TL

foitializing Modf: 5
the nmtrol word for mode 1 and writing a new '.:oum. causf's
OUT tu gP high and arms t.he
. The GATE input has no dfed on t.l1e

OUT
r.i new count during counting has no effect on the 1:unent count.
lfowever, .if the OAT E input is niggered, r.hc cycle n:stnrts w1.th thi: new count.

Mode 5 Cycle
\VlJh the

nrmed. a l<.iw· t n·hig;h transition at the GATE input
The new count is k•<.Hforl on the nf'xt CL.K pulse, but not decre·
1nented. With c;wh successhe C Lt\. pulsP, the count is decrell!cnted. \Vhen the
COlH1t c!Hcrnments tn 0. the fHIT
goes low. H remains low f<>r 1 (:LK
pulse. \Vhcn the co'tmt d.ccn'm,~nts to FFFFH the OCT signal goes high.

•:.IH

After the
i~ armed fur che first time. 'he triggt'r rernains armed until
th!.: contn1I word ls reprograrnmed. Thus. aft.er a •:1mnt ha:; decrerncntcd tu 0.
tlw GA TF; in pm rnsrnrts th1c·

the C,'\TE inpur hcfon.c a count decrcrncnts t.o 0 restarts the evde
on t,hec, 1wx.t C:LF,
'l'lw umnt is relnaded ai.itoirrnticaUy. Uecnw;i.c the count
did not <:.•xpin>. the OUT
J ''rn:;ins high

'.I. hree-Clw.niwl Counter and Speaker · Hardwore Dcscrir>tfon

G- 7

Registers
This section discusses tlw BUH
Bcrau!W hit 0 1.~nntrnls t.hc GATE
input cf cn11nter ? nnd bit l contn)IE< the output to the
tht' systm11
register is also discussed heH-. ·rable (; :1 shnwc; tlu~ addrn%es of the 8254 register:i;j and the sy:sitern

Rl\V

s2r;4 ~ (~ount.er 0
r:ounter 1

ll/\~.'

0040I1

H/IV
H:\V
'\.-V

OfHlH
004 ~~ f-1
OOJ3i!
ooc; i H

82(}4

8~!14 ·- (~onnter 2
8254 · Command \Y<ffd

Systcn1

n.:vv

- .ifordwure

System Register (00f31Hl
7

·{;!:~~~-ri~~:--1~o~~ERl1~~~f:1·f~~Bl~E-r-~~BLE·-·r~-f~!KER ~oooF:RRj
CHECK

SIGNAL

CHECK

PARITY

--•'y"'•H•·~--·-·-----~-

--- ·--·"<<•----~

GATE

INPtrr
H-~~--------

-----~·---,,,._,_,

-~>'~-----~"H

Bit.

Hi\V Dti>'cription

\\'

c\lways 0

COUNTER 2 OUT SIGNAL
0
{ \mnter 2 OUT ~-ignn! is low
Corn.it.er 2 OUT si~mll is h.igb

~-----~--~··

110 ClIECl\
O = No bus J:O error or option Ri\ M parity error
l = Bus !iO or option RAJ\I parity error exists

w
'l

~H"~----·~-·~-

HAl\I PAHlTY CHECI\
0
Processor board Rr\.M parity goon
l ,_. Procc'ssor board RAI>I parity error

~-~~- ~"---•-->--~-

0
HEFH.ESH RJ;QIJBST
0 ··~ Refresh request not active
l 0 ~ Hdresh f\olJUest. active

The diagnostic snftwano l!SCS this bit to check the operntion of the
DRAl\:l refresh
f)

H;\V

ENABLE I/O CHECH.
Eiuihles checking of Uw bus 1/0 check lira.: and option RAM
0
parity \enabled by RO!'vl BlOSr
l .. Disable bus J:O error clwckinp;
~-

H!VV

r.:NARLE HA!Vt PARITY crmc!\
Ennble procr_;ssor board HAM parity
ienabl.ed hv
HOM !JJOSf
Disable procc~isor bonrd HJ\Tvl µurity checking-

c~f ~,~1is

bit is lil\-'{:~~~c=i ~-\'i~J;: th'(~ Ctn1ntct 2 ()t:··r
th:o: .t U.1t~ cr,,unt:t::t ~' ()t_rI.-i
i~
tog~
train to· t:l1t:~ ~r1-B;:~ker t:.ht"·er.
f::Jtpet -h) the spn2H;;:.r:-r this h;t 111dst
1

I~.:V/

C:CJC·~~-r:-I~R

2 (}/'o.'l·E ~NPtrr

t.:·ff~.n-~.t.e: ? (L'\~J-E ·n-~1.n.tt. is kri\.-

1 ::.=

C<.~!_H_itt·r

2 iJJ~rrE~ input i;:;

Control \Vord Register (0043H}
7

--r-- -- -·--1
I

SE LR CT
COUNTER
__ _l_ -

- -,-- --·-· -

- ---- .-- - •

READ/

MODE

Wl'fE

SELRCT

.. - - - · - - - - L

-·--- -~-------···- L

-rBIN~RY-1

I
ICODED
m:cJ
MAL .

-L~ -·- l ____ J

SELECT COUNTEH
Sele-ct counter O
I) J
Select counter J
10
Selt-et count.Pr 2
il
Head-bPJ~J~ c(nnrnar-Hi

READ/\VRlTE
1.'nunt.er-iatch \cOJll!TWIHl
11)

RuidlWrite LSH
RemM.Vrite !vtSB

11 --

!leadiW11t!., LSB first. then MSB •

MODE SFLF:<.:T
oon ~:;:: fvfode U
001. ==
1\-Iode
XHl "~ l\·lode 2
XL\
rvfode ~\
.l 00 -00
Mode 4
101 = .Mode ::,
BIN1\JtY CODbfl DEC!J\-1/\L
0 = Hi miry count.er l i) bits
Hirwry-ci;ded-dedmal lBCD' co11mer d decil<lt':>l

Tho u.mntt:r does not start c01.mting until th;; second
pair is \\Titten to the co~inLer l_atrh

of rhe

l'hree-Chamwl Counte1' and Spenku - Hardware Der;criptfon

H- 11

Counter-Latch Co1nmaml (Control Word Regi!'!ter)
c.

r-··-

-1

SELECT

COUNTER

·-·

SELECT

I
l

O!'NTEH

Seiect (\.n.u1r.er O

Sf::L·ct ('.·our1tP1 1

S(:tect. C:nuntcr 2
(} nth}-fint;cl

f\.J:.J.nter-·ti.n.ch CO!tan.::}rH{s do not ~:~ffef't tht: prO~!Tarnrned rnori~-~ nf thtJ r~ourn~er,
·rhc i~(J\H1ter-J3t-ch con~.n.1i:i.ud. .latchP.s ttH~ ~~ontents of thf: counrers \vit.tv:n.it ufJect~
i.:-)g tt1t: ~'~;unt in r1rc;gr~~~;<t;_ '\'\/hen t:he R264 n~(:eh•t.~s o count.cr-lutch co1nrnand. it
ln.tches tite '~eh;cted 1.~fn!ru.e1- int·o t-1.1(:. {·.oi!:nrt::n; ou.tp».:it latet·L ~rhP latched count
is held ur1dl 1·cfrd tJv !-it(~ C.PlJ ioi ·untJJ th.t·~ couJrter is
j,.ft(~:r ti1e
h;:1xci:t·~d count is rt·tHi tJ1e ov_tput. latqJi folhy,i:;:~ rhe count in the ,~~:(1LH1h;_:r.
V,/hcn ~~ r:ounJ,er-"L:1tch cort1n1~J.nd is SH:~:u,ed for IllOft), thHn OrH:~ rount<Rc -efH'+.h
ruu.nte-r output latch hulds tb 13 c~)unt t1ntU refHl V~·'hcn any g!_\1 Cn cou.ntf:r is

i:-r:Jtnnc_;-;_nd ~;;..: c.f_frT:et.i-v--~2_ \·V,iJcn reHd, the c.ount; J:i:~ th~:J ('.nu.nt. latehed
cc•rn:-uand.

co;~int.er~lot-c~h

:The tntrbed tf'nnt 1nust be re<iG
~11Sl3~ o~~ LS.B and t"JSl5~,

tr1 t"hc .Pr-ogrnrnrned forrnt:it. iLSB.

Read-Bad{ Command !Control Word Registei·)

Bit

R,1\V

Dcscrlptiou

v,:

n
LATCH COUNT and LATCH STi\TllS
Latrh srntw, and count or SH!ectcd cuunter(sl
I) 1
Latch count of selected counterls)
J.(1
Lntd1 Btatus of selected countcrlsi

no .cc
IL

Undefined

COUNTEH 2 SELECT
0
Counter 2 not selected
(\1unLer 2 selected

COUNTEH l. St<:::LECT
O cc-c Counter 1 not. selected
1 _,. Cnunter 1 SL'k•:ted

COUNTEH 0 SELECT

O
l

(' 01m t.er 0 r1ot selened
~c-

Counter (l .selected

The reml·back command b written to the cnntroi word
k:r•ed cciuntrffs. t.he read-back rumrnand latches n stat.u.,; byte and/oJ rhe etn"
rent r:ount.

T!w st.aws
format. is described under Status
is
rc~;d from the indicated count.er register as fl sing!~; 8-blt
\.Vhen the re;id·
back command iatche~; both stat.us imd count. the status
is reti.d first and
then !.he i.:mmt. Thcreatter any read returns mt unlatched count.
The lnt•·hc•d count toilows the fornw.t descnhed under Counter-Lu.tell Commw;.d

If muh
read-back commands are issued \Vithout lnti:.·rvening read->, all but
tbf; fir,c;t are lgnorc<L The status rPacJ is tbe stni:us ar, the time of the first
read·bat::k <:orn.rnand~
ti

.,---

---~

tHJT

NULL :
COUNT

REA!)/
\o1UTR

s.r.:u:CT·:i;;o
MOOE

J.
c~

·~\l

trr r i!~.r
11

t; LL (.~(; t: >J·r
i~e~~,- cnunt: is io-3dec~. and lS av~~uu~n1_~ for
;\tdl COL!··-~,

.n.1:U co~~-n.t bf:, Df "'""" '"''" eotin hJ.r. H th+.; counter ~8
-.vhe1~ t.he scct.Hld. 11.v-t~"! i~ i,.vritten.

Ht::1d/~1Vr_~t(~

0-1
:l 0

!_;SIJ

ftf~HdFVVrite ~v1SU
fti~.:td/V~/ rite L~~.F'( fh:~~~t" t~-H?n

l.1

~i F~ i;-_f~(~]"' EI)

(ffH~

::.-:

.\1 {) ~) E,
[;..'J :)f:& O

X.J.0

!\'i(•de 2

on .:.: :

!VI ode 4
:\'l CKiC f~

x i ~ ':::'.:
l

t 0 1 -~

l COD!;;D

! Df.GJt'J\L
~-~---'

{ !l ;'f p~n i~~

0
--.~~furi~Ar,,;-

j\:j 0t!t~

Bff\1\If''t C()[!J!~IJ f)EC·tlVf,l\L
0 -~=

f11S B.

Thi;;; pngl' is inlentinnally bhmk.

G- 15

Progra1n1ning
Exaniple
1'1u:~

three t':hanne.t count(:rft-iinor and speaker
derno_)_i_-i_st.rDtt"s

exnn1pl~

the CfJu.vter/t:ifner reg;ister~
and disnblJng the output. to the speaker
the output
tc~ th(~ :;peiJk(~.r

routines i:IS des•~ribed in tbe

'l'he cxarTtpie

V\iritt;.~ r;

r;r
bet'P
unb(~er~

tnn spk

i fi-bit v~i.lue to the indicated cD1mter
Cnab1es tlv~ bell
at the
Disables the bell rbeepl at the spe,1kfff
In_itJr.dizes the counter. displ.Jys ~J1e rnenu, and e?:,t:1_·utes the ex~
arnpfr~

prograrn

CAtJTiON
l]_'.flproper

(!l in-1pr(1per or~f;ration ot tJ1is d.cvic.e ~~·rtn

ca~Jf:if~ tl1e \.' ,J.._)~n1z.t-~ "'<Vor~·'.:St.ation

t<J rnalfu1lr:t.lon, 'Ihe SC(lpt: nf

Constant Vr1lues
The

values for function keyi:;. For lnfonna1)_ For n. Ustin1{ of the We

tion about
T!w induded file
to di~ph-iy rJJtr rneuu

F\Y.~ n

ddines the stn;;;t.urG type MFSSAGfC: that ls used
of ~he file cxo;n.p!e)1; st:e ;\ppr:ndix 1\

,.rh::• constant "lflh1e sy,'.:::t~:H· (~.:"'finf:.~ the otf~ct uf the sv-stetn ;)t(lt.\J;:;
[/() Sf.)[j("C.

·rhc tonstant ._,,.:r)!~1c~ cr.,:!·dr'..·~g through
CO! 1 i.tter/ti~n.i:;'.r
ln l/() ~-pace.

'Tht.· tunstarU: \-Di1tt~ iHpf>~·q {Jefinc~ the
tin:t.-::rs

'Hu~t:::.' d(~finc tht~ off:i.tcl- ()f tht: 82.04

#include Hkyb,h 11
#inr::lude •~e:{a.!!1ple, h 11

jto

/• reference function key constants */
/''' reference menu i;tructure

.t-/

define const,antu used to program 8254 timer

Ox61

/* SYf!tem stat.us regi.f,ter in I/O space *,/

#dd1ne CHRDRl<:G Ox43
#define COUNTO Ox40
#def ·i ue COUN'fi (h41
#define COUNTZ Ox42

/'"- control word register in I/O space ·>/
/c< counter 0 :register .in I/fJ space ,,, I/
1~ counter
register in I/O space "t./
/·i.. counter: 2 registex in I/0 space ~·l

#define SELCNTO OxOO
#define SELGNT1 Ox40
#defJ..ne SELCNT2 0:<80
#def Lne SELRDm, Ox CO

j,, select counteJ 0 •I
/ _./; sel eci.• C(HlUt-er 1 I
/ select counter 2 */
I• rielect read back +/

#define SYSTAT

#define LATCOM
#def inc lUILSI:l
#clef i.ne RIAMSB

Ox20

#define RWLSMS

Ox30

TMODEO

OxOO
Ox02

#ddine

#define· TMODE1
#define TMODE2
#define rMODE3
#define TMODE4

#ddine TMODE&

.;,,

/-t-· select latch command :... ,/
/·+, read/write LSB ;>.../
/·i, read/write MSB >:/
/'' read/write LSB then MSB ;.,c j

OxOO
Ox IO

!"' r<ele•:t timer mode 0

Ox04
Ox06

/i: eelec:t timer f".Ode
+, /
/-t select; timer mode 2 .1 /
/•< seJer;.t timer mod<: 3 :t;/

Ox08
Ox09

1~' select timer mode
se lee t; timer mode

4 :!-/

/ ,,,, bina.ry ccunt dat:~

#defi.ne lHNDAT
#define BCOUl\T

()y00

#d.,fine tATCNT

Ox2C

/,;.

-#define LATSTA
ltdefine IUlCNTO

OY, 10

/·t.: read back crud latch statue. '</

#define RBCNT1
#define ltflCNi2

r~ad

back cmd. lat.ch c0unt,

Ox02

read back <..:ounter 0

O"vO•;

i• read bad' count.<'"t' 1

Ox:OB

1·~

#ddine INPFRF:i.i l.Hl3l81 L

-.:}

/> binary coded decimal couot da.t;a -1./

OxOl

/o~:

14.31818 Mh:z l

1•/

Xf'«•d back counter 2
1:/.

l. l93Hll6 Mhz ;j

U- l7

\Vriting a Counter

J\!Iaking; a Bell Sound
~rht2:

function hr~Pp ennble.s tht~ Sf.)£'i!k{~f out put at 1000 f 4i, It
tl1r: ht~H
:j~JlH1df f<)r tLe /\8(:ll charfactcr fiE:L t07!,lL cfhi,s f-unct.ic:n c;1.n be c::t.Ue<l at

an_v ~.irne. l~he

1}utput i~

<ljsab!ed b_v t.he hu1_('.t:i~rf1 unh(faep.

a 'bell (beep soura.i:~ /\ftJ~~r 500 u1:,, fautaL the speak.er ouf:,put is disabled.. If dH.~
rl~al thne cit~ck
~trc nnt Fn_;Jbir:d. the ;;;;IJ~::~'d·~~:.·r f_HJtput i:'«iU nnt be
disat_110d

.. 18

~c_cnt16{l

- write 16-bit value to counter

unH"Lg:ned char

+- /

jh ~hich cc>unter to set

CP!J..t1t-er-.

t1naigned int vaJue:

!~nsJ.gned

int

r to bald currant IF

j_11tr_fl~g;

int_J)ff ():

CCIUNTO,
0~tp(counter

i GDU~TO,

valu~

& Oxff};

~aloe~>

ata~e

/; dLeab]e interrnpts t/
write countex low byte ~;

/>". writ;~ c~unter higb byte

8):

5.nt_on{~n~r-~·f 1ag);

16-bit ~altJ~ */

4-/

enable tnterrupta */

/ --:' b~ep ()
-·.:>- :'.,

ini heep_flag;

/* tr11e

( nt) (Hi!'fRl".Q
rn1tp(SYCiTAT ~ OxOJ);

1nOQL}l;

tf ( +--H:_i~'£•P. _.f laf\

beeping ~;

/·J; vet desired frequency

/* turn epenker on ~,
i• aet flag, speaker i• on •/

be<'p .!111.g

if (hBeµ ,f'.i ag)

~bile

.,, 'He we :::a.king a beep sound ~ /
ha.s it bef!n on long enough ':-:/

I¥

{

o:z~p(RYSTAT,

Ox00):

/t: turn. it o.ff

be''P" f J at~ ·~ 0;
}

6 !9

Counfor and Speaker Exiimple
1··11e function ti1n
t.he

initfolizes the •:ouuter, displays the 1nenu, and executes

/* tim_apk() - execute ti.mer and speaker· examples

{

a,tatic MESSAGE mti7:!..
{
1"8254 Timer and Speaker
{
3 ..:'.'1
Exa~ple 11 } .
{ !) 24 "fl.
Set frequanc~ to spea%er" },
'
{
~i f''2.
Speaker on 11 } ,
6
2~
{
Speaker f!ff'i }
7 24 ' 1F3.
{
Dfj-RE-M.l'' '
8 24 "fci
{ 9 2<1
~'F'-10. Ret.u:r-n t.o Main m-enu'' },
{

()

n },

};

static ittt toneiBJ ~
/k frequencies for notea to do-re
{
2281, 2032, 1810, 1709, 1624, 1:3€6, 1209, U4.0}

char 1rne(512] ·
unsigm::d J.nt in1q;
unsigned jnt tval,
un~igned

to hold input line

rAm~mber

fraquen~v

•1

/* general t~mporary
/·~

:cnt. \ ;

iteration

~oi~trol

/-t- <.le:ftned in clock examp]e -j/

extern unAigned i.nt metronome·

!~ ~sj.ntainP

beat of do-re-mi

#def i rl(i R.DW 1t.:

:ttdeJ Lne COL 1 ·1

l:tnefO} = fJ;
I• default frequency •

Lrl?q ""-· i 000 =
i*

ontp ( CW!W.RE~ , SELCNT?.

inl.tiallzc c0unter mo<l@

lUILSMS ! TMODE'.l

whHe(1J
{

disp_:renu (wt i m :•pK) ;
si,.;j_tt:h(I:inef0.1)
f

case Fl:

disp_0t

/-1<-

CUL.

i'Ent~r

B-t2't

new frequencv (19Hz

cut.pu~;

·fre~:;uent.y

20000Hz)

•i};

get_keys(ROW, COL+ 37, line);
sacanf(line, "%dv, &freq);
if(freq < 18) freq~ 19;
elae lf(freq > 20000) freq
20000;
tYa.1 :' (int) (INPFREQ / Gong) freq);
wr_cnt16(2, tval);
disp_menu(mtim_epk);
breok
case F2:

outp(SYSTAT, 0<03);

i•'• turn speaker off +/

case F;}:

uutp(B'fSTAT, OzOO);
break;

/• play do-re-mi +/

c:ase F4:
i ~ O;

1mtronomf' ~ (b:ffff;
whiJe(metronome) ;
wr_cnt16(2, tone[J.J 1]);
ontp(SYSTAT, 0;<03)
whi) e (i < 'J)

iteration count = 0
/, prepare counter to O'l!n·flow */
/1 wait until it overflows •/

/* start firat note •/
I~ enable apeaker •!
js do all notes *I

{

if(metrunome

/* hold note for 500 ms

{

wr cnt16(2. tonefl•+)),
metronome- :-.~ 0 ·

/ s:

/·~

ne).::t note ,., /

reset counter */

}

/·' redisplay time for menu "' »/

chlc_dt (}:
}

autp(BYSTAT, 0~00);
val z (Lnt)(INPFREQ I (long)freq),
wr cnt16(2,
br·eak,
case

Vurn speaker off ~:
reset frequency ~1

t~aJ);

FlO

return to caller ~;

line[O] •get fkey(};

get function kej'

}

Thrt><"Chmind Countel' and Speaker - Prni<rnmming Exmnplc

Chapter 7

Video Controller
Introduction
'1'!1•' V,.'\Xmate video contrn!ltC! is un th<: r:o bo:;rd and drl1'Ps a m011uchronw
rnuni.t.tff 'fhe video C<}ntrotler can proc·f~ss l G r~Jiors or shad(~s of ~rray·. ln this
the term col.or abo me<ln~ slHHJe.'.i of gray rn
levels.

Industry-Standard Text nnd Graphics Features
The V .\ X mate video con!:rnHer ha:: !:he foll<Ywing industry-5tand;1rd tnxt and
f(!at.ure$:

coiors
color~~· or 8 bn-ckground cnl~)rs

blink

::t2n :--< 200 •1 (:.o1nr:~
G40 :~ 200 ~~· r.ni<xrs

Video Controller · Hnrchvare Dcscriptinn

7·

Enhnncernents to Industry-Standard FeaturN;;
The viden ccmtroller has tlw follcrwing 1>nhancements to industrv··stnndard
features:
·•

The scr0cn H::solut.ion is H40 horir.ontal
by 400 sc~ln Uncs.
lndu~t.r1.·st:ind:.rd
(~WO scan lines} is
dispbyinp; ei.Jch scan

•

The chi.l.racter pattern is fl horizontal pixets by t() :<nm lines. result·
in,g in hit;·lmr quality d1:1racters: in t.ext mode,.;.

The 2ii6-clrnnwt.£·r font RAM pro\ldes fie ·;ibilit:y in terminal flllHlo·
tk)n and rnult.iling1.ial applications.

•

Tl1e duai-µur-t video rnernorv elirninate~~
scree.n flicker (disabling rhc screen bef(1n_:. accPs~ing \'ideo rnernor,'t~r i.s unnecess:1r_v ),
'fhe i fi-bit; d{{to
acccs;S rt~sult.s in

to video rn•}innry. coupled with thn dual-port
SfTt.~en upd.at.~H

Jndustry-St.andard Features Not Availnble
vidt>o c1)ntrolkr does not suppon. thes•; featun·s:

l I.HJ x.

00 J f5·coi0r graphics mode

').if:; !{Hz monitor supp1.1rt

•

Hnrder col.or sqppor1.
pt'=n :s1~ppnrt

Extra Features
The video r<mt.roliet ha& the following- :tddidom.d _gwphic foatnres:
840 x -JOO :!-<.:ok<r
(HO x: ·100 4-r-nlor·
6cl 0 ~~: 20U 4 .. cu~nr g·rapl:dc&
}\00 :-: 202 l··<:olrx
;~:~o ;< '.200 -.l H-cnior _graphics

•

7 ~· 2

2f10"-r-barai~ter $Oft: feint

Video C'nuLroHer

l-fard.t\'an~ .i)t•scription

Block Diagra1n
The viden controller t'rmsists of a display prneessor nnd video memory- that
reside on the l.'O hoard. ;\s shown in Fip;ure 7-1 the displfly processor includes
a translation ROl'd, a G84fi CHT •.:onuoller i:lcxt video logic, grnphicH video
a video look-up table. and status and control reghtcrH.

VIDEO GATE ARRAY

__J

Figure 7- 1.

Bloek Dingran; of the VAXmnte Video Contrnller

The tnrnsl::1tion HOM transLJtPS indusr.n·st0ndard eol•ir
data that i;; \:orrnct for tht~ .DIGITAL vid\'o controller.
The fi8.:15 CHT Controller \('HTC! intNni!l rel{i'itt•rs cnntrol horizontal ;md vertical pusitfoning, synehrm1iwtion, video and cur<;or
widdi of vi<leo display.
Two statu.>

monitor vertical synehrnniwtion. video

tirne. and

variou'i. rnodes in the control
'The tv:o cnn.trol
enahie the YnrioH-S text and .~;ru_phic•-: rnnde.<;;. Pnabh:
trnd disnble tho display. select the font f{,\M, ~Plett the video look-uµ iabk
\'Vl;n, and provide !'>Creen saver suppm·t

Videu Controllet' - Hardware De'-'tript.i1ni

7 - :3

fi.1i f~~
ot dua.l ,ported roen1or_y. -.vh.it:h rn.aps intn the address spHre of the
i-\_X_rnate C'.J?tJ

\ 1

Tire
proce~.sor converts 1ne1noty d.:1ta into \7arious raster fo.trnats. 'fht.~
display proec-~~sur g-enerHtes ll{(HJ output~~ that drive the _cnonorhrur.ue rnr.JrtitA)l".
The VA._)(rnate; rnonjt.vr displays the color i:nforrnntic1n (lfi d~fteren.t !eveL~, of in~~hHde.s cif gcayL

Additional Sources of Infonnation
Tbe
Cuw.pariy

fi84-f)"-I

HDitlcl05S

.:.,,--Jntoroki
Hit11;:bi

DocHmei1t

Video Modes
The video controller has several modes, some of which h<ive <• mode number
assigned indicating t.lrnt the ROl''>'1 Bl.OS suppqrts these modes. For mod;~s not
supported
the HOM HIOS, the h;irdw1m: nmst be progl'ammed directly
For rndtJstry-srnndnrd color graphic acbpters the difference lx,twecn H color
and a m<n.iochrnnw mode is th'' prnc,ence kolod or absence imonod;romel of the
color burst sip:nal in the conipnsite Yideo output. Beu1use the VAXmate viden
cnntroHer does not provide a •.·.omposile vi den outpur. there is no di.fferem·c be~
t.v,/cer; the c..::;~qr nnd the nJunochron1c 1nodes.
On pm\Yt'!JP or system re~et, the video system ts initiali;:,cd to mode O;·HI.
Table 7-1

Avuilnbfo Video .M.odes
Description

OOH
fjj H
O:?h
03h
n~ H
fi()h

(J(lh

dOh
d lh
d2h

40 x 25
40 x 2h
80 _X 2~-·
80 x 2fj
320 x 200
320 x 200
!\40
200
'.l:W :'.\ 200
040 x 400
640 x 400
HOC• -x 2:J2
GYcO x 200

text n1ode mnnor:hrorne 1industrv·stand;1rd1
text ni.ude color lindust.rv-st.and<;rd}
.
wxt rn.ode n10n1.1dirome \industry-st:1ncbrdi
Text mode •:olor fiHdustry·staiHlardi
4·cnlor graphics mode \indusu·y·8t:mdai-di
m'lniJChnmw
lindvstrv·stundarrl!
rt'l<J\lochrmnc grnpbics mode q;~dnstry-st.midard!
H)·color graphics mode \digital extended) ~
:~ colcrr graphics nwdt> <digital extended)
4-cohlr grnphi•·s mode idigitai extenclt~df
4-coloi gTaphics mode ldlgital ;~xtemkdl v'
4·coior
rnodc 1 JHOITAL extenondi "

No Hl)l'vI BIOS ~upp!irt
Lrnitcd HOM BIOS support

Video C!mt.ro!ler

thinlware Description

'fext JV1odes
The vidi:H) r:ontrnllcr has 01 I\} KhytP t.ext huffor in the address
B8000HABFFFH. Video mode.:; OOH, 0 UL 02H, and OTH use the tex•
for modes OOH and ()I H. the te;<:t. buffer pruvides 8 display ptiges cf 20•18
t;;y·b, For modes U2H und o:UI, the tt!Xt buffer prnvides 4 display imges

Character Buffer Format
A dispbyed c!wrader i'l
cwo consecutiv<' b,1ttes. The first
of tiH.! ~~-h:vTte pni.r. i~1 the ch~~ractr,r codt;;_ 'The charoctor co<..h-~ .i-s stored Lit an
even addn•ss. Tlw second byte. of th!• ~'.·b.l'te paiL is the ;lltrihuto byt<:'. The
attribute byte is snnTd at thn odd ;;oddn;ss following tlw dwxacter code. Fig1Jre
7 -2 shows the dwrnet1•1 code and attd!ture
addre!:islng. Table 7<! Jt;:firws
~}u;

of each bit vvi.tbin the <ttt.ribut.(·-

B8000H

H8001H

BBOOZH

BB003H

BBFFRR

BB.FFFH

Even

Odd

Even

Odd

Rven

Odd

Flgm·e 7-2

Cl.rnrncte1• Buffor Fnr1mH.

Bir

(}

f}
4

Uh
Bb
lf
HJ

r"·
)!

(~rr:ejt c~.:intribut.inn to

ForegTound i.n.tenslt_'\/
H.~~d cPntribution to forcgrounr1 rnJor
(rrr·eo contrihHt!on tn forcQrOLtnd color
Blue contribution to
··
culor

~fi1f--· se~ectinn nf b(H~k,r.~rtnJnd
l\.'1.)Dtrrd
/\. (~0ntro! register

YVhen

c.olnr

Bh.'e ;:ontribution to

or blink fils dct.errniHed

bit 7 of

is th~.'.:jr:.ribt:d later in t:bi~-:; ct'1apu-'r.
iB enabkd. the blink freqwmcv is 1.9 Hz

Character PosiHon to Memory Location ]\-lapping
CharnctN p1witions on the screen are identified as row lverUcaH and column
\horizontal! locations. The first character if; displayed in the upper-left corner ot
the scremi. which is !or:atinn 0,0. To translate between screen positions and the
addre;;s within the te:d buffer, use the following formuln.

Attdbur.e address
\Vhere
Display page start address \sec Tablt• 7.:31

0 to 2·4
column -·

n to 79 \80 X 25 modes)
0 to i!H 140 X 25 modes!

80 180 X 25 modt)s)
40 MO X 25 modes!

In text modes. the video processur supp<:>rts multiple display pag·cs. F1Jr dirnct
programming. registers RJ 2 and R 1 ~1 !described later in this chapter) control

the display·page stnrt address. Each displayed charnct.er reqnires 2 bytes khara1-ter code and attribute byte!. Therefon•, the 80 x 2fi modes require 4000
180 x 2!:) x 2) and the 40 x 25 modes require 2000 bytes
MO x 2f; ~; 2L The HOJ\I BIOS also support14 rnultiple display pages and

rmm<ls the mernory requirements to 409G bytes and 2048 hytes resµecrive!y.
Table 7<3 shows the dlspby p;igB addresses as defined by tbc HOJVf BIOS.

Video (~outrolter

Hard,vare De!-_wdption

7- 7

IJHllVI B!OSi
80 '{ 25
Dh;phl,\' P<lf;e

4{1 K 2\i
Dh•play Pngc

Bi\OOOH

HUki.lflfl

P.rogrnnunable f\1:rsor

hits

4-0 nf n;fdsLt_,~~s BJ 0 .:Jnd fll l.
thi'i

ProgrammHble Character Generator (Font RAM)
Th•-c Vl(ko cnntrnlier rws ,, 4 £\byte progn1mmabki font HA!VL The font RAM
can stnre patter:1s for 2fi6 drnra,,tPrs. Normaily, the font !li\M i<> accesslhle
to the v)d.e•1 controller. Thnt is. the font ..Ft.AM is nnt mapped into tb<;
11ormvi CP\T ilddreBs suaCE«
the font lt\:V! requires t.h£it t:he video
mndu he· •}OP of t.lu~ !;f)?.t nHxles OOH 0 ! H' fl2H, or rrnH. Bit 4 of cnntrol
t.cr B !des\:Ttbert iBtcr in U1is r:hHpter·~ contnJ-1& access to tt~t? fnnt _fl.;\!YL \\!hen
~;it 4 of rnn!roi
B equn!.s L arocc~;s tri the video texi. huHer is dls;;blcd
;ind access to the
HAM is <::nahl<:d. Onl\' even te:o;:t huffor ad.dn~sses are

BBOOOti

0000! r ifirs t

H80PlI-1
B800~'1-!

l.180frlH
B8004F~

0002H \lhird

Bb00!Ji{

N()'T'R:
'The H(f\if lll()S tk~t·:;~~ ~-1ot ,~oppt~r-;:. the u::~~ c·f th~~ font It"\~,.,,- ~n

./\ ~·hnr;Jc:tr:r p~Jth}rT1 czn1~d~t.~ of tfl
nt
infnrrnn::k~n E-lif'.h
repre::-H~"Ets S consn-n.1t:iv.f:·~
of ;~ horizont.nl s;c:.~H1 i~n(~ for ~ht' charact~~r. 'T'he H1~}<:_:(.

r~~ad ~-ir

\4i·t:tt.en to an ~~,_.ert ~idd.res~ ·Thus, e-acb cbaractet pc..t-tern n:quires :{'::'.
c.1-ddn:_:~;~s sphce- and f~.n. entire 250-ch.aractc:r fonr requires 81\
c(d~_~:,_date :'be ~-.~dclrc,ss of ·~-ht· fir~!
of a ch~u~.'.1.cter p~~-~tera; .t$e d1P.
1•

~f;ri_:a~.i~a:

G·raphics ]\lode
Ench pixel on the s<.Tccm i<i nwpped into a bit-tieid of thr ··onesponding byt<; in
the display buffor, The wldth uf Uw hir·field can be of L 2 nr 4 bits depm1ding
on "i.vhcther
2.-cnior 4 .. C1)lor, or l()~colcn~ forrn.at is chosen.

Jvlapping the Display to Address
The log·ical
consist~ of a n·dangular army of 200. 252. or 400 scan
lines; of pixel''· For 200 sran line rnode, the lwrdvvare gencrat.Ps two phv'1Ical
'c:c:rn limes for <•ach
<;c;;in liiw. E.ach scan line is
r':\1 / 8) *

~v here~

!'v1 =-· Number of
P''r Nc;in !inP
u ---= l_~ for !.·-bit per p~xol i.?-colnr
n
2 _ fnr 2-hits per
(4-cotor
n _-:. 4~ ft)r 4-bi.t.s iJcr pix.f~-~ {1El~co1or
'Tiu~ ~1V~D1(Wf 1n;:;;ps frH'

varions gr:-tphic ff)nn~·ittl arf~ shown on ttu.:

pk1ges 1~~)Ch rru?-rnflr'j' rnr1p shov,;s tivo or rnon:.~ hioeks of n:H:111ory· t.hat teter to:

!L l\'IOI> PJ -~ R

l. l~ thu desired. scan line
P is the nmnher of memorv bkicks for the curnmJ video rnotfo
h: is the renl~lhHlnr uf the (:JiF'ision L. ! P

~120 x

200 4-Color Mode

ROM BIOS Video .Alodes.· 0411 and 0511 · lnd11strv·S1ondord
In -I-color mode, a single byte corresponds to 4 c1msecutive pixels on the screen
with t1w most significant bit of the byte corresponding to the .left of tlu~ screerL
See Figure 7<1 for the nwmory organi;.ntion. Sr,n Fig1Jre 7-4 for the pixel to
bit-field map.

T
!)

I
G
1
T
A
L

(I, MOD :?)

(L MOD .?,)

v
I
D
E
0

J~ BBFOOH

BBF3FIJ

L = SCAN LINE 0 TO 199
Figu1·p 7-:~

Merum·y OrgRr1iz:ation for 820 x 200 4-Color M.ode

CBl

CBO

·-·-r-~-·-

CBl

CBO

CBl

Lf:r·r HOST PIXEL

f'igurc 7-4

cno

GBl

GBO

HIGHT HOST PIXEL

Pixel. lo Bit-Fi.eld Map for 4-Co.lnr Mode

Video Cont.roller · Hardware Description

7 -- I l

320 x 200 16-Goior J\:lode
in ! (_i~(•J!n1· 1notle1
the ni<~st

on the

~cte~~n ;i".~,(::.h

160 HYn;s !'RR SCAN LINE

r·--

j EBO\iD;<
(L MOO 4}

: nr;pQ{}H

L_,_
l~--------

u"\09f.0!

!BAOGOH

BBf3FB!
' -.

H-i:CHT PI.XEL

6tl0 x 200 2·Color 1\iodc
[n :c>color mode. a single byte corrc!<ponds tP 8 conseeutlve pi.xels on the sneen
with Hw inost sig·nlficant bit of the b.yle corresponding to the ldt of the screen.
8ec Figure 7.7 for the memory <>rganization. See Figure 7·8 for the pixel to
hit-field mop

i··- -·------·--· 80

-r liliJQO(,;;
I

BYTES PER SCAN LINJ-~ -··-·· ··~···-~·

. -·- ........

-BB04Fnl

(I. KUD 2)

T
A
L

v
l
n

lB9POOH

B9F3FRI

BAOOOH

BA09 FB

L----····--··-·-·· ·······-··--··-··-·-·-···---··· ···~-------~-.,--··-··· ...i

(1. MOD 2)

L ~ SCAN LINR 0 TO 199
'i-7

lVfonmry Org:ani:wiion for G40 x 200 2Colur Mode

_,e

·~

CBO

cno

CHO

CRO

CBO

GBO

CRO

LEFT

RI GUT

MOS'f

PIXEL

640 x 200 4-Color Mode
N,1 ROM BJOS Support ·DIGITAL Ext('uded
In 4-colur mode. il single byte corretiponds tu 4 consecutive pb;cls on the f>Creen
with the tnost significant hit of th':.' byte eonesponding to tbe left of the screen.
See Fig·ure 7·9 for the memory organization. Se'" Figure 7-10 for the pixel to
bit· field map.

-T- nsooou

B809FH

D
I
G
I
T
A

(L HOO 2)

BBE7FH

(L MOD 2) - 1

L ~ SCAN LINE 0 1'0 199
Figure 7-H

CB:l

CHO

Memory OrganizaHon fo1· ()40 x 200 4-Color .Mode

CBl

CBO

CBl

CBO

LEFT MOST rnmL

7- 14

'Video Coni.rolle> · Ifo.rdwarc Descriptim<

RIGHT MOST PIXEL

640 x 400 2-Color M.ode
UOAf BlOS Video Afode: DOH · DlGlTAL Extended
ln 2-color n10de. a single byte corresponds to 8 consecutive pixel;; on the screen
wi.tb the most. signifin1nt bit of the byte corresponding to the lett uf the screen.
See Figure 7-.l l for the memory <:irganization. See Figure 7-12 for the pixel to
bitAidd ninp.
80

BYTES PER SCAN LINE ·········-···-----···-···-·----·---·1

1- [---- . ··-·. ---- --- ··--·-···--·· ··- -·-------- -· -------···-··----·--·---·····--·-:1
BHOOOH

B809FH

(L MOD It)

D
I

B9l"00H

B9F3FH

~ ~---~---~~-

~ ~"-

~~-- ~

• -- •

-~~-~-~----~w

~·--·~-""""-----·-----~~-·~---·----····•~

1
T

A
f

'·'

v
I
D

E
0

BF.09FH
(l, HOD 4) •• 3

BFF3FH
L •··• SCAN l.INR 0 TO 399

Figurn i] l

Men.wry Orgmfrwtion for H40 x 4.00 2-Color Mode

.<.

CBO

cno

CBO

MOST

RIGHT
MOST

PIXc:I>

PI.XEL

LEPT

Fi gum 7-.12

Pi.xel to Bh -Fidd Map for t·Colrw J\:'fodte

Video Controller , Hardware De~crl.ptlon

7 ~ 15

640 x 400 4·Color J\iode
!n 4-cnlor mnde., <i
byte <correspond~ to 4 conserutive pixels 1.m thi scret•n
witb the nrn':'t sigEifkimt bit of th<': byte cnrre;;ponding tn the ldt nf th€ screen.
See Figlu'e ?·· 1}~ for the n1eni1ory
See Figure 7·-14 fr)r the pixel to
btHidd map.

·1- !--------·- ·- - ---------BOOOOH

I
G

IB3DlWH

--------~-~

B009FH
~,

(L MOD 4)

B3RlPH

-~~-

r-- ---- ---- ----- ----- -------------------- ---- --- ----- --

1B4000H

(L MOD 4)

!HlDmH

L _ _ _ _ _ - - - - - - ------- ---------- - - - -

T
A

-~----,

B409F8j

B7EJPH f

-----·~ ---------- ----- _j

----- -- -

rBaooott--

-BR~Jgpal

;

~~~lROli_

BB~:'!~ij

HC09FH
(L MOO 4)

1. ~ SCAN LINR 0 TO 399

CH1

C:BO

ct11

iL __

GBJ

CBO

cno

GB1
RH~HT

7 - 1{!

CBO

MOST PIXEL

800 x 252 4-Color 1\f ode
RO:\! BIOS Vidr·o J.Jode: 02!-l !Limited ROA! lJIOS' Support} ".DIUlT'/\L
Exietided
ln ·H"olor mnde, a single byte r:orrnsponds to 4 consen1tive pixels on the screen
with the most significant bit of the byte corresponding to the left of the screen.
See
7-1.5 for tlh; memory or.t;anization. See l"ii:,rure 7-Hi for the pixel to
200 BYTES PER SCAN LINR --·- ---·-"-

"T BOOOOII
B3010H

BOOC7H
B3137fl

0
[

G
I
T
A

(L HOD 4)

(I. MOD 4)

BB137H

1
IJ
E
0

BCOC7Il

(L MOD 4) "' 3

.L
I. ""' SCAN LINE 0 TO 251

figure 715
7

GBO

CBl

i..EFT HOST PIXEL

Figure ·nn

CBO

cul

CBO

CBl

CHO

RIGUT MOST PIXEL

Pil.:el to Bid''ield '.\fop for 4.Culor MmlP

Video Controller · H1:1rdwure D\~scription

7 - 17

Video Look~ Up Table
The video proressor has a vidmi Jnnk-up tab!<~ \VLTI that trans.late:'> flttribute or
gnipbic color data. Th• VLT is nrranged as J(l word'' of lRUB 'Jlltput. dati!.
Each location corresponds to one of tbe 1 G possible colors. \A/hen Uw videu contrnl!er ae1·.esse'i video memory, th<) at.tributes or graphic data are used <is an
nffset into the VLT. The contents nf that loentinn in tfo: VLT are SN1t to the
Vt(leo output drcu(L Becano;e the VLT hafi
rn entries. the VLT GHl alter
the color interpretation of the bit map without rewriting· every
0•

For '.-'.-('olor mode graphics ~G40 x 400 or t»lO x 200!, the foreground color {pixel
equals l i is determined by true color-selc'ct
bits iJ 0 The background
color fpixd eqtrnls oi is determined by the contents nf VLT entrv 0. The color
sele<;t
is defitribed later in this chapter.
NorniaUy. the "Vl .T is accessible
to the video controll<'J'. Thilt is. the VLT
lntu the norrn;!I CPU address space. Accessing; t Ile VLT n~quires
that the video mqde he one of tht· text rnodes OOH. OHI, O:LH. or O:iH Bit 2 ol
control
B (dcscdbf"d later in this chap1 eri controls ac<·ess to the Vl:L
\Vhen bit 2 of control regi15tm: B equals 1. an;ess to tho video text buffor hi
disabled and f.l<:cess tn t.h1~ VLT is enabl.ed.
i•; not

NOTE
Oniy wdte acn·ss to the VLT is enabkd. To read the VLT inprngr;:mi the video p:·o{·essor for :520 x 200 J \1-c:olor
mode. For ,,ach of die JO
co.tors !OOH ·OF'Ifr.

\V;iE until the
I._;

equat~;

[lisable iCPtJ interrupts ~CL.1 in~tructicHJ}
B bit 7 r:.cquais 0)
SUitns

tents of
,,,

7 - 18

A bits 7 ..1 HHGl3) ai-e cqunl rn the cm1·
VLT locution '>Pe6Hed by the color valm'.

Lnable CPU interrupts lSTI instruction)

Video CmHroHe!' · lfardwnrc D1:scripli•Jn

Only 1wcn·text buffer addresses nre connected to the VLT. The text buffer tu
VLT nrnpping appe11rs as follows:

Text
Buffer
Offset

vi:r

Text

VLT

Otfset

Buff.er

Offset

B8000H

OOOOll

BBOlOH

0008H

OOOlH

B80l1H
B80l2fl

0009H

Offset

B800111

B8002H
B8003H
B8004fl
B8005H
B8006H
B8007H
8800811

B8013H
B80lliH
B8015B
B80l6H

0002U

0003H

OOOAH

OOOBH

B8017H

0004H

B8018H
B8019H

OOOCH

BBOOAB
BBOOBH

0005H

BBOlAH

OOODH

BSOOCII

0006H

B80091I

BSOODH
B800EU

B801BH

OOOlH

OOOFH

B801EH
B801FH

BBOOFH
-~-~~~-·,--·---··

OOOEH

B801CH
BB01DH

""-,~~-~ ----~-~ -~ ~--~--·

...

~-'----~--·--"-----·--·~

---~-w-.,-.,-,,_·--~._,

____ ,,, __

~·---~-·~-·-

___ ,

Text mode attributes are referenced in the 1mfor IR.GB, but the VLT ml·
dre!<sing nnd contents ;arc rcforencpd in the order HGBL To cnkulate tbc nffset.
ucressed by <1ny !ROB v;iluf', use the following bit values:
Bit Value

Attdhute

I Untensitvl
B \Blue)
G (Green)
R iRed)
c.

Thus. a text attribute of intensified red \lllGB = COH> accesses lncatlon Of!H

oft.he !H locations in the VLT
Oo power-up or system reset. the VLT is initialized tn tb8 vnlues in Table 7-4.
The VLT values defined in Table 7-4 support video modes 001-L OJ H, 02H.
o:nt 04H, OfiH, OG.B and DOH. When changing from <my of these modes to
video m<KlB D!H or D2H. initialize the VLT to the values dctined in Table 7-5.

Video Cont.roller - Hardware Description

f\2

;

Coh~r

f:ont-1~11(s

(,'ffSt.?:f,

A_'.j

D'',,

D'.>

~)J

.'\0
f

DIJ

;)

n
n

lHtensHv

Black

I'
.}

(}

bhw

{'~

'
()

n
0

'-'

;·~

~ ~i

{}

t i

.--i

,!";.

TnblP l'-5
Off<iet
A:1 A2
H
G

YtT Content;; for Viden M.odes IHH imd D2H
i\ l

AO
l

Cn11tenls
D8 D~ DI
H
G
B

DO
J

{)

0
0

Black

Hed
Light cyan

Not Used
Nor tfsed

i··Jot lfaf,d
Nut lJqpfl
~~(ft_:,

U:;cd

T'.fr:tt Used
~~ot

Csed

t-Jot l)(olcd
Not Used
~Jot

U'led

'Int. U%d
1\Jot Used

Video Cuntro!lei.· - Ifordware Dc;cripti.nn

7 ·. 21

Video S~yste1n Registers
T:.ihle 7-(} 1ists die videCJ pmce:>sor input/output lf/0) regbter1'.
'Video PnJ{'.<'R&or J /0

Tablt: 7-G

0:-IDOH
0'.lD.tH

4-0

Compatibility

CRT(' Indnx Hegist~r
CHTC Oat.ii Register

D!OlTAL Extended

7-0

rvw

O;HV>IJ

J.-0
7-0

w
Hi\\'

CHTC !nd!'x Register
CHTC Dat,1 Hegf ';rnr

I11dustrv-Standard
irnlustry-Standard

0:3DRH
03DDH

7-0

7"0

Vv"
\V

Control
Color Select HegisLer

Jndustry-Stanchird
Jndustry·-Standard

G:1D:Ui

Status

-0

01D4H

D!OlTAL Ext\mded

/>.,

O:HHll!

-~,

DIOr!AL Extended

7-0

n
u.

Status Register B

(J;i Dl:H

\.Vrite D<lta Register

!HCWfAL Extemle1l

(i:;DFH

7-0

Control

OCIWH

7-0

f{./\V

Special Purpose Register DIGIT.Al. Extended

7 ·· .-,.,

Video C1rntro!.ler - Hiu·<lware Descriptiun

DIGITAL Extemkd

Special Purpose Register (0C80H)
7

~:~_~J~~°[~··-~~f"'·]~i~~;,j:i~~~J:~~·L:~~~1
Bit

R/Vr' Descr.iptiun

Write protect
0 0° Sdcctcd diskette drive is not writP protected
l c:= Selected diskette drive is write protected
0

1 n1ek 0
0 c,, Head of selected diskette drive is not at trnck 0
1 ,=, Head of selected diskette drivl? is ;1t trnck 0

:- ~

Index
0 oec. Index hole not in posirkm for selected diskette drive
1 '"' Index ho.lf., in position for seleetl'rl diskette drivP

Speed Indicator
0 "" Modem control speed select. asserted
l.
Modem control speed select not as~wrted

'.i

fUW

Disable Video
0
Video controller disabled
l ·'" Video 1'nntrol!er enabled

RiW

Split Band Ifa.tes
0 '"' \Receive = Transmit "' programmed)
1 ""·- \!leccivc = 1.200t ITrrw-;rnit = programmt~df

HiW

l)isable Comnnmkations
0 -- [ntegrnl communication" ports connected rn IiO address
space
integrnl communications ports disronnected tron1 110 addn°ss
space

S11ced Select
0 '·" Speed select asserted
1 "". Speed select not as:serted

V.ideo Cnnt,1·01ler · Hardware Description

7- 23

~lJ'i;;J~s {}_ the er:t.irf:!

fJl(;J'Ti\L .,_,ldec1 ~ystetn is dii.:connr-:t:'.ted fn.nn the tr:ernorv
iii'-Cl J/tJ c11:ldress ~:fKiCE. rt.hi~ ;Jfk;;vs thf_:'. in;Str~H~Jdon t:iHd U~e of

H the HOM B!OS find,_; en
up sequcnrt--:_ !SH.3 H<J.t'v!
P !k~)vs thf:

!- 24

video t.<dnpter during the P'-'Wf'r-

n H)S rJ!-Jar~ bit :i !)f the spef'.LiJ.~ purpose

."J,t~nuJard

·vid.eo

to tun(tl\JH t<Vitbt)Ut t:l)n

l'l'hi.'.:;

CRTC Registers
The CRT controller \('.R.TCl has two registers. t.he index and data rngi!lten:L
that an: !Jccessible in the CPU IIO space. \\'riting a vahw to the index register
sekcts one <Jf tho 1. 8 internal rngistern RO·Itl 7. The selected rngi.i;ter is read or
written through the dnt.a reg:ist-cr.

Index R('ghit.er i03DOH!O:JD4H)
7

RS1

RSO

RS'~

RS3

RS2

HFG!STEH SELECT (HS4-RSOI
A v1.1!ue betv..-een 0 and J -7 writ.ten to this
tbe corresponding- internal
lfW·RJ

·rDI

7-0

---~

1)6

5
----

select.~ one of

4
3
-r·.. ·---- ----, --

-~-~-·r-

H!V;C D11ta and wi.dth are dependent upon thE> rHgister selected by Hw
index
. To determine if t.he datlJ register r:an be read or
writte~L sen >Jv~ description of tho register selected by the index

Virleo ('.onlru!ler · Hardware Description

Th;., inde.>; and data ref;isters can he accessed tlnougl1 two sets ot I:O ports.
The industry-~tand1u·d sei. is 08D·l H !index} c!fld O:IDiiH \data I. The DH.HTAL
extended set ls 03lHlH Ondex! and 08IHH ldata), Hata written to the indwitryst<lndard set pass thrn11g'h a tnrns!ation HO.M and then go to t.hc CH.TC. Data
written to the DIGITA.L ex.tendi:d set go directly t.o the CHTC.
The tnmslntion HOM converts CHTC parameters. for an indw;try-sf;amlard
color graphic'$ adapt.er. tn values that M~) correct for the ext.ended
of the DIGITAL \•i.deo system. Thus, applications that directly program the
CHTC of an industry-standard color graphics adapter function cornoctly,
Table 7-7 !h-:ts Uw CRTC internal registers and their functions Tahle 7·8 !i"ts
the
punimeters for the video modes defined in Trible 7 -L Thf!
iwrnrncrnrs
ln Table 7-8 nrc written to the CilTC tlirough the DHHTAL
extemled ItO portl' 03DOH \indexl and 0:3 n l H {d;;tn).

Tuble 7-7

CR'TC f.nterna! Registn1;

Regiswr

Hi\~'

Desnlptkm

OOH

VI/

OiH

Horizontal total

RJ
H2
lB

02H
0:111

\I\/

Horizontal di'lplayed
HnrLz sync J.)nsitiim
Synr: width

0'7H

\/e1 tical tota~
Vert.k.til total adjust
Vertical cl!splayt;d
'\/err!cal 'lync

08H
ODH

w
w

01\l1

interiace/Sk'::'-w
l\·fax srnn litw flchircss

Ill J

OBH

\'.'

(:.ufS(ff Start
Cur.~or end

R12

OCH

R:W S!mt adrlre<is
Ili'N Start addrPs" {L{lW b_yte1
R:vv Cursor adrlrf'~S {High hytel
Hi\V Cursor address \Low

04H

();; 1-I
OGH

Rf.i
R7

HH
R rn
ru:1

OD!~

R.14

OBH

F'
-.t; ;_)

OFH

HHJ

lOH

UH
The DIGITAL video

w
'\/if

R
H

Light pen 1High
~
Light p<'ll \Low byt<?) *
dues nnt s.upµort-

Tnhle 7R

C.RTC Registe1· Values
320 x

200
'f·color
()4(} x

6411 x

400

200
?.·<·o!or

4-color
320 x

800 x

200

2G2

Hi-color

4-culor

04(} x
200
4-rolor

()40 x

400
2-color

80 x 25

4{} x 25

Reglste1·

Graphic-,; Graphics Graphics Gniphies Texl

Text

6!JH

50H

83H
ti4H

69H
50H
58H
58H

34H

69H

28H

MlH

34H
28H

2CH
54H

58H
58H

2DH
MH

H:',.,

f>8H

GDH

Jti

58H

5AH

R4
H:"i
HI)

:HJH
OOH

OIH

GDH
OOH

6DH
OOH

TlH

;JFH
6::lH

ti41I

H?
HS
nn

<J6H

(i4H
G\lH

40H
01H
OOH
OFH

42H

<KlH
OOH
OF.H

'.~2H

4011
07H
OOH

Hl.G

rni

OFH

Hl2
UJJ.

OOH
OOH
OOH
OOH

RH
Rl6

--·~·-~.~---

----~--

HDH

OOH
OOH
OOH

oou

~-,,----~~~·"·~~~~·~·-

J.AH

11\H

fl8H
19H

OBH
l\JH

19H

HlH

40H

03H
OOH
OFJ!

OFH

40H
OFH
OOH
OFH

OOH
OOH
OOH
OOH
OOH
OOH
OOH
OOH
•_u_"_.__ ,__, ______ ,,_ .
"'

-~ .---~-----~----

oou

OFH

OOH
OOH
OOH

OOH

____ ---·--·-------"
,

OOH
OOH
OOH
OOH
-·-~--------~~

Video Controller · Hardware J)(•srrlption

7-- 2"7

HORIZONTAL

TOTAL

tlClHIZONTAL TOTAL
1'bis
det-errrdne~ t.he horizontal svnchrnniz:ati<t)rJ
l::. is thP nurnber of displayed eh~racters ifi_f~ plus thP retrace hn
c.l1a.r.Hcrer tin1r!A~ rninus t:JJ.1c.

d·~-ter-:l~L.1~-s

::;;;e rn.H.1'tb fr o!
0

ne ~GS:i~ t-b_an

{~hara.ctt~:-~. c~n n

;n rw

I!ORIZONTAL SYNCHRONIZATION POSITION

TU:;
tiGil
C(~~Li:·-;'!·,.d_

':;h't

V·/t.irn t:bH~ vuine i~ in'"
>value is dc~:~re.~"1ked, tLe

~j ;nJi.s·e v.. ~cit,h of :ht~ ~~;d~ratcd ntH1iht·r .-"":
H pui:s•; ·~. .,id th nf _i H

\\'idth Ctf the indK.~t:ed r:iC.J"Ciher o~
~·=h~u-actf:V

!~ iz.:;.i.JtHl

O~ r.L:.(;"'~ <~ ht~dzt•ntai

3
l/BR1'ICAL

TOTA{,

()

l
VERTICAL TOTAL

Bit

ADJUST

--·1

l{i\V
~---"' ~

---~~-·~----

-----····

w
in addiUon

Ifogistn RH
7

VERTJCAL

Bit

R!\V

De;;eriptlon

.Always 0

DISPLAYW

VI<;H'flCAT, DISl'LAYED

This value specific:'! the number of dbplayed chanwter lines. It
nm,:;t be les8 than tlw value in HA.

l
l_

VERTICAL SYNCHRONIZATION POSITION
0

B.it

R:\V Description

\\'

i) {l

VEHT!CAL 8't'NCHHONIZJ\TION POSITION

Thik value determines the positi(>n of the vertical synchronization
delav and the ''Nticai scan
\\'hen thi>1 l'alue is increased, the
rfo;piay shifts up. \Vhen this
is decreased, the display shifts
down.

J'v1l": ct.,n.tD, 0_?t,!~r -~:1(t:·!,v
In'"-:~i\d

L 0
Bir

~.~-- ~l-~.----. _J_._.,._ -

-----1-~. - -

H/\i

lVIAXllVP\M. SCAN UN
Hnc;:t per

Rl.O
1

r-- --------r -

- i

~·----····--·-·· ~-L ____ ,_ ...J ..• ---- ___ _l_______ ~L---

--~1--

CURSOR ST.ART

CURSOR lHSl'LAY

MODE

0
-

~--,----

CUHSO!l UJSPLi\ Y \-l(ffff;

00 !J ·1

4-0

CUHSOH STAR!

Vi1foo Controller - Hur<lware De,o;rriptfon

I
l

R.H
l

r·~-

CURSOR END

w
w

CUHSOR ENll
rhL'3 value
tht-: ~chn .Hn.:-;. ~,~·'ithin r.he r:.h:-n·acter s:.~efL !}n
\vhich d1e ~r..1rs<ir end. ~L ./\. vnhH~, of 15 ends the ('Ur~or at th~
l1ntJorn of tJ-:i·e char0.'.:ter cPJL

RegistN'
5

{'
-!

-- -----r-

START ADDRESS
ttlGtt UY1'E

rl
L
!

t __ _

START AD!lltESS
WV BYTE
p~1ir that d~;terrnine \Vhich part. of the

a:Jdress in n 1 ~~ Hnd R, L~ HlUBl
first chai';:u~tf:r

Th~~

Regi&ier Rl4
6

r----l----- -

I~-~i_J

CURSOR

HIGH
0

-,-- --- - - -T---·- ·-----·--Anoru~ss

BYTt:

____L ________L ___ _

---------rCURSOR
LO\/

ADDRESS
BY'J'E

l ------ _i______________ __\ _____________ ___l ________" __ j_ ________., L------ ______ L

HJ-! nnd Rl. 6 ;1re a re-<ichvdte
that- determine t!m iocntion of the
n1rsor r;s un. offset frum the bcg:inning of video HAfl,:L The ;1ddress in H.14 and
H l f~ must b.-._c an even value. The rJddress points to the charnder byte of ;; ch;n-

Video Coni:rnller - Hal'dwt<re Descripthm

L1GHT !'RN POSITION
HI\~B
!r'f1_'E
__J_

UGUT PEN

LOW
R. J. t:~ a n.d H. 17 .are n rf;,~-g-1 -;.:trdy'
dr(::s~ ~-·/h_en i·.:rn~

rosrn ON
WfrE

Stai.us Registei· A IO:lDABl
7

VI.ORO

VIDEO

VIDRO

VIDEO

VSYNC

i.lGHT PRN

RETRACE

VBJEAJ H - Virko
V.ide~.t n.:d

1nH.1.~! ive

-Vid-t:fi rr·d

nc.tivt?

O ~

Video green

"\tl.d(::tJ i;~:·i:,~~;n

:...::

inacti·vc

active

VIDEO B - Video Hlue
0 -= V.i<leo bl·J.e
1 -Video hluc

v·syN·(:
U ~~

\; (~rUr·at

\.' erticH.! sy n _-:.ht·nniz.ati.on ~,r:-t.i-ve
1

:>1

LftJ1-IT' l'.EN {(-~t'.Jlntents undefined)

R.LTHACI:~

\Horizontal nr vr:Tt:h:;;!l

Beumse tiw

interference ca~ised
~xidt·o rnt:tn(lfV,

prograrns that: do ~~heel!,
B€cans.e =;~ retrace
is checked. Lhi~-~ .ha~ the

is not

For

tn be u1 effpct evcrv of.her tirne it
up vi.den rl1~n1n:--y

B {O~~DDlU

Statuf.
7

VIDEO

CR-B3

CR-B5

CR-Ali

GR-Al

CRAO

IH..ANK

;

;>':<

CHECK

Cl:!ECK

!?ORT

Cf-t·-Jf5
t\-)n"Lrol .Register B bit 3

en~.~bled)

(0 .tl.'-I~~G

t:on.!._;-oJ
4

!-t

CH-A.4
(:f.n1Lro1

T.'..!-

'.HH.!TE CHf;( l\
S.in(t~ ~he ·ivdti!. (fr~ta
(iY3 ~JE1ff_J \-V{Ui l.g::~f:. reiH1~ au I/()
\o~Ti.t~ tG p(n-t. 0~1f).J lI or ();),l)f~!-! lH1S j}(1t t;(~~HrL-t_~d.
Si;1(.i:1 die lvrir·,e dat.~1
iOa Df~l-l; -~:a~ Ia~'lt rt:ad, an l/(J
~f,:dtt~ to po:-t 0;31)411. or OHJJ5li ha!i or;curred_ T·bis b~t i:--;
:-:::i~-:-tu.-ed hy reiHHng the vvrite data regi~te.r nJ8fJEI1~.

P(HtT {)l~F:(~l{
Of the

\Vrite Dat.a Register (O:JDElO
I

I
R

Cnntains the last darn written into the CHTC
register
fHD4H or O:lDf>fL Stl:ltu'> register B bits l-0
which oort
Lhc data was writrt>n nJ. H•'ading this ,..,,..,""''"Y dears stat.us r~is-lster
l~ i..!it

Color Select Register (03D9)
5

n
Bit

R:\\'
Al.ways(),

C'P8 - ()oh1r Pat1'tte Se!ert !See Tabh' 'j -~.l and Table 7-i O!
\V

ST(' - Selc<.'r fnknsified Color~: (See Table 7-P and Tablo 7-JOi

J 2

lSee Table 7-9!

():::~~·~

200 z.: 2·-Ccd<,;:;-

{~,:iU

:..: 4 ~jfr ,X :.~-Cotn;·

NOTE

~-~p~ ~;

sr('·

Control

A (03D8H)

(:f~lJ t1'fr1.

;~ ~-n x 20U >~ .:i
i'Olor

G-+O x 400 "'-' ~
col(:r
i)

indubtry stand:~rd

Control Register B 10aDFH)
6

~52 $C<.:ln

n.ex:t_
the dbplay,

;),

/\. bit f} 'g'Jl(Jft?d

A bit 5 enabled

FONT HAM ENABLE
0 CO' ;\<:cess to font H!\ rv1 disabled
I = :\ccess to font RAl\1 enabled

V\/

DISPLAY ENABLE
0 '"' Display bhmked

VLT ENABLE
n
Atr•'SS to video lnok·up t<ible disnbied
l\ccess to video lnok-up tahle enabled

\.V

I b!Hnks the display. The
or l!O ;weess to the video '>ddres~ soac.1.; wcrwhlf!S
to 1 for nurnw!
'

CH-A5 ENABLE
Control
l '°'· Con t.rol

cnnblf'd

.Pl

Hnes

o ''"

·)

I\lONTJOR l\'lODF
0 = 400 <,con lim:s
l' :_·.-

Progra1n1ning Example
The

the \ridf:'.!'."l (.Ontroller for ;:1
luokup tnblc;
the font IlAM
NOTE:

Of-l video calls ~{re
v.ideo baru,.i,·i1re.

l)o nnt mb; HCiM BlOS ('alls und rlircct ,_,,,,,.,,r-.m
hBrdvvnre"

CAt:TlON

the
thi:::i rnarH.:;JL ·N·o uther t:·:.;t:;

list

J{eturns ri pos.nter t-c~ charncter :5trin~_; th;!t de~cdt1f_~s th;;: inrj;.
ca.tt:~d. rnod~.~,

Reads f.n' yvrites the font (B_rn

}ui tj aiize~-~ t·.he ~.rki_1._~~) c1.rntr.r>UE:r fu1<l H1(Klf·
i_Jt d~LD

fra~neJ,

o! t.he s~_:n=::erL
~t HK!SS~.g:(~, ir1 r.b0 ccnt.t~r oi
c1,ffrc~nt niodH

•

1 ~p

•

tne ;_:(;n~,: ;,:<):~;; ;;;,rgJ ext;c ~tk;~

the ,.,,~~reen" tha~

This poge h; h!t•>ntiomil.ly blank

'rh(-~ ro~•.st2n~·.s ctf~f]n~d 1(, ~.r:i~:' e:-~1Hl' 1.p~i~ n•.-i;.~: ;n t..;1t' ~n~:hi<le ft fr:': 't/1 rTEtJ. fl
"rb(· 0U1er lni:iud~.~ Filt~;s, E:X,.:\l\fP_LE.f:I a.~1d f(YBJ-L supp:i)n:; tht: e·\arr~µJt:= bu1:
~1.rf! fH)L ~ierti:~!.cn·:

h.:: OH:;: v~deo ~::t:~.: r.:un.

=rhr: ;:onst"tnt '!/::~1i..;.(::~; lfJ-ll}I; ~tn.d f"~·\LSP iHT: ~.lst;.d: (L'\\ tnHin.g p1·1;an1t1 ter~:; fo~· ~~~·~-1,,

etdl P)Uti!-~18'.:S.

v1de:o _n1e1n-~)(V. 'l':H~ ·CCn1~tant . . ~~~h;e \7"fH) d.•"'.fi~1e~ t.!1e l/j\){ tnoC1to f'Zi..t?nded stD.rt ar~dn:::ss foe cof.;:)~< gr-:tph~cs vide,.·~ :nel~.-:.".°.'•!!l" 'i.~~•.e::ie •/:<.~.v;Z:! ~H'f': far

·~s 'i-vr~t t-~:n ;3t

B800 !·I:GtHJ2 ~~. {~eg~

t..~1;~:~f: can hf~ d:td~~·~~~d a:~ ffi~ :·.i:Z:!.'=::. ;/ ~-_:f
!:ht~ ;,•:ch_;:'-3 ~nnk-t~P tah~.f;. 1t ~~h(hI~d i.'L>t ta: :·~!~~:'.d

t}€C'H~Jsc ~:O per;:.t:::nr, i°}f th.e spJ.t.:~: r~.. €...it;.id

1·v·bcn '"·-~~~.;

be \\;~1stecL

he defi~:..t~-:::~l {::~ v. -:.~·'d)-din:~f::)')i~n')(:t ii"':.-~1y ~·-~r ~~t~·i:,;e:t.tu:.:.·<; ci'f typ~~ l"··c~r~~·T. ~·~,h~~::·~_: th:".7
;\; 1r:,·. ;. .;~F_ic~_:, t.":·,~:t th~s

'Th~ ~~t;:.~:..;_;::' :.Ii'(~~ ~~VT!~·: .~d -·r_.:;J~LE: dc-d~fH!,:_~

data C~f

t,e µ_;~•.'.~f.-~:~<·L:r~ i:.be \Llri~n~; ·~ri~~f.:G ff~f1i:_h-:s. Lr;.t~::r l:n. ~;~'it'":
tL!~~-·::

(;t

r21Lt~-~en

'·! r;

#<l<• L.ne
#def 1ne
thief }J:!i:~

FALE~E

();.. fffi
01.0000

CR.TC~._. .I~JDEK

0f0'.-~d0

#d~iluc

~R:L;

lltUi~

DA1~

o~_03d1

#define C!RL_REGA

0~03d8

#dt!:i"ine COtR_J1ELG

0.1<Jl3d9

/8 FaJ.se ia zero
register in i/o spRce *I
/.~.- .t:::rt~~ data regiate1 i.n ::i/o apace
·r-·:·
cnntrol register A in j/o ep~ce
/* c0lor select zegjater in i/o np•ce ~;
;~ ata~u.s register A in !/o spacP
:x oi:atU$ register B in i/o space
1~

crtc

inde~

f:x03dn

oxo:Md
()x0.3df

control

r~gieter

B t11 i/o space

VU8

GxbUOOOOOOL

/·+· normal l!aG£< ll.ddrt•!la of vJdeo :nemory ,./

/EO

{JxbOOOOOO'CL

"7:tem:led b<1ae addresc ±/

u.ns ign.~d ,-: ·nl!ir

char

vJ t.byt.e:
ckJ.p _bytoC;

chaL-

f0_;:-;J. _tJ;tc;

Uf!S: ignPd <hn..r

skip.byte;

uns.ign~d

vlt entries a1. even addr·es~ • ~
1~ akip byte al odd addreaa ~•

~!I..'"'f;

t\.TISi,g:nf~r:t

J- :rcr~. -~;
tJf PdPf

f,1nt l'!ltries at even address *f
i" skip tJyt" at. odd !l<dd:res,; '-'-/

St1"'";_$C t

{

'..trt8igncd r:ha.:t
u11~ tp1ed
;_1f.!S igned

LhJ~ r

rn:~1:i.g:i:\1~d

:-:b.a.\

·1nnigned char

long
Ut'LJ i~!1ed

int:

1;;~?.:J 7. gr;.e<l.

J. nt

uns'igtH.\d in.L
UU;"-l;"igned in.t
~;~;'J;S.t,~d.ed

} ~~"TA.BL;;:,

oi-:(::

chi\r

.tnt

c ra;
-:1 h;
~~~,

base;
nsp;
!"j)rJ,

f,b;

!-~

point~r

intc crtc_table ~/
po.j_nter i.nto vli._table *I
!% ~ontrol r~gister A valuP (Tabl.e 7 11) ~r
/-+- cont.rnl :regit;fP€:r H- 1~1'alue -r:/
~olcr ~eJect register VAlue {Table 7··10) ~J
:1 Pegment:off&Pt base addreR~ */
n.umh'2'r of ~c,_n pagef!
/* scan page ffize •/
11 rolnc bite pPr pi~el
bv·tee per eharacte1· !in~ or scan line

/.;,: in t::ha.:r s.

.oL _pi~<r-1-B d.~pending

on rr~t,,de

.~·/

'T'hf~ g~·nEy ·.JU~ aeHn:~s ~Lx .~E<t.s

nt C:rrr !:T1 '·1tT(~iie~- in_lt:iBli:z:.;'~ti(1r.1 ·~/dit.1es. -rhe

nsed :ne th(~se fisted tn ·T"nbh2: 7--8. -..vhich supp<)l~ts all i,tf Lhe defined
V/\X.rnHte \~id;:~c; ~·'.ncde.::~. N(Jti<·i:_~ thvt cnch ~~tHte supports rnor.f• th<:n1 t:H:e v~d.r~n
m,xJc. l.11 t.h;;t c;r,.,. '·.he
fl, tht; color H:tf:'.;t.

1.r:du~;s

Tbe .trrr;J)t z:ils deftn{~~ t.·\!l;{·i ~::0t~ l:J ·~·ltico
1>:lbk: irri·d£diznticn~ ·1-"tdues l'T'ho
v0.h. H:.>S'. t1~t:·d are tJ-uJ~t" frst.ed in "ra.b:e .r·-.:.; :HHI ~rr.bit_) 7~:). ~r~Uce that E~~~ch state
svp_po:rts n1(ff+) z}:.:d'1 ~tr~e v.ideo ~·node 'I"hL~·~P rnlr-itH"dl~:;l-1h1s ure dernonsto::ted Lu~;cr
in the rnode t-abh~ d!.~fin:tton.1.'c:an1p!e u<;es
dt.~.n.loi1s.rt.r;j.r:l·on"

NOTE
"J'he t.wo vjrk~c= n1odc·:~. Oxfe

Ed Oxff, are th>t dt~fi!!ed or Huµ~
pprted by ~:ho flC~rvl Hl()S. - 'he cn·:xie au_rqi~'Bff< O?;_ft~ t1nd Oxtt,
;_:_re defined
Y-'i:.hin tb.c .:n11tr~ !·)f ~:hi~=:

'. 50

the

Define tab1e '1al11ea anrl d<!clare globalB used in examples

/;:.;.unsi.g_rH)d cha:r c.rtc f6] [16]
(

/""' Refer to Table 7-7 & 7-8

Ox38

0:-~2d

Oxb4

O,•: !a

Dx40, O::r{Jf

O.xOO

Ox Of

OxOO, (JxOO

Ox l 9 OY 19
'
0;,,00 0;;00 }
Ox19, Ox19
0:-:00 0:<,00 }

{ 0?.3·1

Ox08

/-+ TEXT ·~-i
40

Oxf\9,

0::50

();(68

Ox58

()yQf

0.'o\00

(h:Of

Ox1a
OxOO

Ox08

Ox40

'c Ox34

(h:rn

o-,:~:c

O:r54

Ox6d

0::00

()x40

01003

o~oo. ()>;Of OxOO ' o,,oo ' OY.00, o:,.oo } '

0;•,00
'

0:<134

·~

X'.

7.5

TEXT

! :i-' GRAPHH:S

0'<:66

/
/

.,;. l

200 " 4 '>/
/ ,,. 320
/:,,,_ 640
200 .-,._ 2 i
; ,,.
640 :-~ 400 x 2 ...,_ I
")"'.

{ 0_f:69
Ox42

Ox50

' (ht:0:3

0:<_58

OxOO

Ox58
Ox Of

O;d;d

O:zOO

0:<00

()y()Q

Ox64 Ox66
(h:,00, ():;00 },
:

{ Ccd3.3

0.:(€4

Oxfi<l

Ox.Sa

0:,<6d

Ox40

Ox03

();< 00

(h0f

01':00

Ox£9

O:diC
Ox.01

Ox58

();.(58

Ch·:OO ~

OyOf

{

O.>:_,;o

};

Ox01 Ox:3f Ox53
OxOO, OxOO, OxOO

OxOO Ox32
OxOO. OxOO ' OxOO

0.:36

}

0?:.33
O:dlO }

GRAPHICS >!./

,. €40

400

.. 200 ::>: 4

640

l i'

,, 4 ,

/ A- <1Rl\PH1CS .l- !
800 }C 250 x " :"" /
,,,;

GRAPHICS

/ < 32-0 :.:: 200

1.6

:-\' ;'

>m!lifl,Ded >:hH.r d tR [2] [ H\J
1.

r o~oo, 0:.:.01
Ox04,

O:;,~.Ob

Ox02 oxrn
Ox06. {».Oe

See Table 7 4 ~;

oxoe. Ox09, OxOa

Ox Ob
'•
OxOd, Ox..O? O;z<H ').
'

{

OxOO. Ox.04, c.,os 0>:07'
OxOO, 0;;00, OxOO, 0>~00

/8 See Table 7 5 •/

Ox0(). OxOO, OxOO. OxOO,
O_,..;,OO. OxOO" O:,JjQ' OxOO }
}
JJ1t

n:ode __ 1 iRt lnJ

'· o~oo

(h_Qfj

0:<01
Qxd(l

Ox02

Ox03

(hdl

Oxd2

Vldcc• Controller

Ox04
O:de

Ox OS
0.':H }

Prngnmuning Example

7 :H

.::in :ttrrH;r- n.f strr.:tt~,;1.t~·;~.• ~.:d t,'.:/flC Ivf: 'T/\}JL.E. E~E'th :-~~..rt1c~
·:~) ~h,.,t~~ t~1Et ~'1r\; r~-c(tcJLf'ti t:c~- ~src~U'fan::1. 6

!\-! 'TA-BL.E: "--._.

'J-~~e ;1.J: ray· r::~~:::-;:;~)g•::· i~:. t~_qt, req.:;ir~'"d
p~~-·gr.;10~. =.~::::e~; .G

t,{_: p~-~--:e nE~I tht~ vi,::Jt.::~·) cno(:.:..~5-= 1 f·~•. 1\-\'th't r. th·-:;

ir~);:11 tb.t~ ~~rr·:;-=~1 n~.t~f-:"'..;Jge

fH:: cttn_·~~r.t \-·id.c~f;. rT;(~d.e, .i.,he ~!;1p~-(Ypriff~:e
·;·h_.c .ar!"':;\.." ;;!:·, . ,., (h;i~r;(:S U1f ~·:b;- r:_-;: :·;_~r
:-i;; It i~~:-, t-_;jt~·~~ -t.(: d:~·:·ncr:~·~,rrf-e

i~ "=k:t.er1Tj1·:~;c~ hy~

f'.F!{~ f~!Ftf~JTfl

th£.:> ft..1~H--~-ti'J~1

{

kc rte 0 ) [ O]
&r_ "':'i; :i.: l;J [G}
ff!c. rt .

:i l f.Oj
, ~u::rt~; 1 j t 0 •.
,.
l. iv r't ':.: 2} [DJ
I
tc .rt.-c
' l D'
{ &ct -s-c 2} f, 01
'
i._ &c_ n . c 2J I 1.)}
j
{ &c l" t,;,": 3 ' ff'«
'.;...'.,..."
{ ii;:;: .tt.'-:: 41 [O}

0;..08

Oxf.B

:,"'ix_,:10

\T~P-

D:(-0 400

0:;:04

to:

(b·Ol3

OxbB
Ox68

Ox(~·:)

VS8

~:;

0:-~·(jt,

O;;J.!O

Ch::04

Ox63
fn-fi.B

VHS.
v88

Cx.04 Q(~
o~{ Ok10G

(i; U'}

Ox.-6-tl

l);.»00

VE0
VH8

,,,,,. t . s"' [eJ

nxoa

&v 1 t H [O
ii;·,· t

' "

(o]

kv Lt·, '3 O]
I> lt-n i l. )

c b J [01
.
&c•:.r ~ c. 3 J ' c

0x00
0.'.'!'.09

"- J.t :> foJ
!r; lt $ [O)

.-~

{ &c

?>l-'

t__·v 1t fl (0]

& ~· j t

dl:v lt s l '
fP.• .. :fl [OJ
,i!;-:c 1"s [ . I

-..

C}x00

OxOn
Oxl 3
Oz. 18

Dxti8

0:-:07

'/HP

0;.:63

G:-:01

VBH

Vx 1 ~

Oxf.i8

'JxC10

~1n0

0 ,. lb

Ox eB O:t.O~~J
'
Ox6H n:o:OC

\'En
vm~

Gx6U

;rr;,;:3

OxOb
_,.., __

'-,_j).,

\);,(}()

,;;,-J

Ox.0300

0:<')4

2f:l,

o~.:-

2000
Ox2t)00

0;.:02

80
80

:;)():)

~?C;O

,, ' 0?;2<')00

(}:-:01
0x0 '

20-D

Ox:1noG

O;;(!i

~~/":

.;DO

Ox4i}00

0·'!'._0.J

H~n

4~)0

Ox.::1000

(})'"~(;::-!

Cx201 }::

0A04

Ox4CIOQ

o.~JJ2

2".!0

)50

:£;;
16G

';QCi

··

J~~C

]'__ 200
2GO

mcn1nchrCl~~~·! 1 ,

54G

2·"cO -~.0::·~

6~0

x 400 ~

2 c~l~r 1 i,

,. o':-~oo
' D,.:G~2

{jy()(l

O~":.-fe

~>~02

Ox(l2

0.xJY2
c-.x f

O;r:f;?

f!.:<02

ty:~)(:

(1'.<00

GxGO, 0;---.<>J 1 ;

chsr ~ .f~nt[2561[16 ,

fort
t~nt

~idth
h~igh~

~~rrent

Vidc•J Cont.rnlh:r ·

i.~

JlixelH

in pixels
~ri~~o

11ndc

200

'rhc h.;.rv:.rion .r.rer n1.-:;-:.-r(~ n- prc: 1/~(ies a
datJ-

'\OTE
r,"-t'O -.,.·:-oec rnoth2.s Oxfe and (L'-df. ;;1re nf1t definf~d or '.J'.~n~

T'iH~

b_y the .H.CJ~v1 _Bl C>S. -rhe rrt1)df~ nu:nber~;;

nx.ft~

and Ux!L

~J_.rc dcfi.;:-i•.:ii '.)!1!y '/,,i;:.hi~1 tht:~ lirn~r:::: 'Jf this

snurr_:c for

t.hP curt~~nt;;;~ ?:1-f·I_;--:~:t.ed ~...-id.eo n.vJde, ~rhi:,_ !-UtH_-~tittn is
pr~Jgr~-~ln ~:h.~-~ '/ith~:i CHOdC:B. hnViE.Yi/'Cl'. it ~~ ~--i~;er{ to JjUpptH:t, tht·

descY:ht;~s

ret~ur:ns

a point,t1r to

mode

t~.h] e

int d_mude·
{
nwit~ch(d_ rr:ode)

dist:over desir~d mode ~,

1 ~

{

0: r~twrn (&mcde_table fO) l:
, . retmn(&rc1:ide.tahle[t]);
2: -r~t1;n-n(&mode_.table[2]),
:-i x•>turn(&mod?_table{3]) .;
4 nit urn (&mod,.. __ ta.blc [,;j};

' :(:

ret•1rn(&m<)dl'_t.;a_bJ~(S]);

/-;· '.'$;?,l) x

return(t~Dda

.· *

case OxdO· retuni(.!rnwde_ tublel71):
ca~e Oxd1: return{kmode_table[Bl);

"
/
"'

case Oxd2: return(&mode table[9]).
caoe Oxfe: rorurn(tmade tablellO]]:
ca.se Ox.ff" ret1.~rn (krnodfl' . tab i cf t 1]) ;

'25

40 x
80 .'".. 2S
I * 80 >:
320 x 200

table[6]),

'40 x

640
640

200
l'~

color

~· /

-·l col0r
monochrnme

., colo1:

200 ~'\.
400

.-:--.

___,__

2 .CQ lnr
64() -· 40(~ )'._ 4 -col~r: ;}800 x 250 K <1 color _, ;
-320 )'.;: 200 x 16-'f'.:'c·lor .;o/
{)40 ·, 200 x
4- <::o1ox i. /
];,

}
}

/4 get_nesR __ p() returns a pcinte·r to a atring thu.t describeR the mocle

char J·g~t~,:r;,.nss p{)
{
flw itch { v id_ mod«)

{
r:.a~e-

case
ca.s~

{0} 10]);
0
J. ; return(&measage[l![O]):
?. retuxn(k~eaaage[2][0]);

C<l$.?

?:et.1irn ames<>a.p;e [:1J [OJ i ;

C-t'!S0

4:
f, '.

returnC&meaoage[4][0]);

[5jfOi);
ca~':le
& : return (&i;m.,.usage [6] [O_l) :
.cage- (!xdO t·ecurn (&:message Pl (O]} ,
,~ase
i)J-.ri1 : return(&meeaagc[R][O]);
caJ;;10: O:•.d2 '. return (k.mNisage [91 [01) .;
case Oxf<o
ret;urn {&message fl OJ [O});
c-a.s~

(".~P._f!

Oxf f : return(imessage[11JlOJ);

40 ,.

: --+-

26
~Q

coJor

2E~

130 }'~

-l

80 x

200
;>:?O
200
640 x 200
/
' 640 ;·: 400
~)20

I -{·

}:'

~·

/
-;.

:.~,

!\4() " /J.00
800 '· 7.$0
'.'20 " 200

640 v

;J~)O

Jtl·-colo.t·
'-i-co1or.

t- /

.! :

jnjti~ljze

~3it

vl·t

i~ ,~t1.vs

~~j.~.t~~

until di~play

~ i c?'i.a:y

Is ~nJhl~

vlt .. b~t~ ~

~r~a1·~

J~_:,_'tf~' \'CTR!·_,_J\EC'f!,

r~:~;;!~;,:~d

vit ~~~~~B

'1."ibe fur:rcbqr: r
false. it rnads

!<cad~

nr tvr.ites tht.~ font. H.AJ\-1. _ll thf.'. parnrnc;t.(:r di;· 1:--:.
furn. ll;\fv1_ (Hht.·rv..·ls~~, it .,,d·H.es t.n tJte f(1t1t il/\.ivt

a:·r ay of byte voluns

mo<fo3. The mode i"
c~1tt;d

h_:;." \:i.d _rnode.

/\lso notice thot thf· rvutine v1.·nit~ unt-n video hJanking t.irn.c to
erfH.ion nnrl that •,rich~o our.put is disuhlt~r.i ~_Hl n .:turfL

from the

fo~t

ram atartiag at the indicated ch~rftctet

1~' r~t£1ter tc·

in-:

dl.rec:i~n

fl:i r ~

/*
1t

{

.:rj·nd~" init('2)

o~tp(C7aL_.RfqB,
CUH.11.~:

pl rd
p-f~t:

,-:~:--_.:;,:

t~~l~):

~1.~rt

fgnt

&7r~y

t0 nove f~~t ~ate
at this ct1a1 valuP

eutr.her of

~h4io~t~~

>!'/

f011tn

Tho f1E1ct10n .:.;}(·d~ 0
pL:fc:~:f.: the video procL~&Si:'Jir in a
the p~;nLni..<-~ter rt r:n_uch:~. ~[llc t:1ldeo

1.nnde .t;t;:~t~:~
hiiHt:olitA}d
and th~~

2::; in;.iJcatf·.(!

Hec~uJ.st~ tht.: (~.FfT co~1t:-ulk~r !_~;;; in .fut unsr::dJi:.::t ~::at_}j dt~dng: inJtiaf~zadon" the
...,·1n·c·:; :-;ur.n;:;t n;.c.~t: L::G d.iB~l:bi-cd.

Thf: r:nT{ cnn7.:n>H~r J~;-:l\ u~'.. inter.nid
R ~ G ;1ntl H. 1 ~, a:r ::~ r?.a.f~
7

tn'. ;:::Jtrt':':'J~!e~· bas h:;."~J r~·:-:tt;t n;:s~ u~r,rist~::rs, th.e

t.t:·r. ~To ac-~_~f_·'.:.s 'HH::: "Yf r1-~c 18 ;nr;~-:r1Hn

ti!l~"e ~A) !)'l"Ct-,.'f:·nt

()~:.h.er ·)~J::::r-~~~.icr~.3 ~T1:g·~:.•

'LE' hF'i:h•;r !Iii
hxc•ti<.u.

i.·;.it.<: ,.

.)fit~

vv-riu~~ ,.__i1'E' desired

th.e <ta~:·

r:n<le~inlt()

'4".

J.n.lt 811.zee t.hf' .-:rte and 7:1od~

regi~t.e::rs b~r ii!CVin@ri

to the appropriate registers

-t :loop r.:ontrnl
pointer i;o crtc_table •/
/

£~gisteT

char

M... TAHLE

,.:,p~t ·

unstgn~d

in.:~

t~·

*pc;

/'' point'i'r t:o rnode_tab.le '"
f'-,1,
CPU IP sf'i'tte ;/

in.tr. 11;f}g;

pint
get ;n_c;:ri~ .p\_rl~!'\1 1 1ci~).
]W:.df\),
intT _flag
"'1t, TRUE} ;

< 16;
Ol~tp(CRTt .. lNDEX

i);

outµ(Clt!(~._DATA,

*pc+~}

!• Ret pointe~ Lo video mo<l~ tftb:i~
I* no iutPrrupts plea•B

zl.t da~a */
/:1c ae1-1ign potntfl'!' to c::rtc_tJl.\ble -~:/
/:.:.i: du :ce~),~ters RO through It1$ +./
!~ ~rit~

.:~~

i'flch t:~~-·~3 ih'?si:r-ed

r~gil'Jter

/1. w:r-~t<S C!'[Ji:;rnpr i.~.t~ 1,;aln~

.!'
~n1tp(G'fRL_.fH~'.fiJ\.

pr"t;t. >.::-en.)

:::vi.rtp(GDLR_.GEL{~,

prct ><:sr).

~pMt,

pci~tc~

r~fister

~-.T~BLE

~;;:~_~i.~ned

3.. H"'

prrd::

r~Lr

1.2!ig

s~t_.~ocle_p(vid_modc);

Pe~

set

c~1,trnl

regist~r

A ~;

t:olot select regj.~te~ ~·
/ *· a llttw 1 rrt.exrupts ,.., '

vid~o
l ::,

mode table *!
IF ~ ta.t~

GF~.T

~~ icter~urts please ~/
got ~~inter t~ Yi.d~o ~cdR taLl~ ·~/

}

'"f1'·-_1t: hhic;--.ir,,.n ~:-L1··-";c,'•--

on pos~Linus t11(-" r:_:ursnt ~tnd turn~3 the (~JrsiJr un, ~o Lhat p~

~s ~.-i=~ib~~~

:~ ciesired ro~ p0Aii.io~
/:r:

::".tt:.21r-ei'1 cc:lU.!fl':l p=:-:1>:'.Jt:~fl:n

;{

~.ndic~it@

~1-it.e
11td!~a~e

wr~te

~e~jzei

1es~ted

H-I)~~-;.:-,

~l~~i~~r

~aJue

int~r~u~t~

1;.J):

;11--~tr:J f_CR;f~-.;, Jj;\TP...

iI~t

v~~ue

teg·~_nt.er

~ppropriate
alI~·~

,::-(:1~i;(Ch'n:-

rcgls~er

appTopriat~

~~~~;

;

writ~

app~!'pri~he
~;. j o:_;c,~t

~al 1 ;e

}_H-t.>?!- r ~.tp (·. :3

t.. ,-

'I'he

cst.ablbdv.~s a

bbng; thr'!

screen ~vid~o rr'!r-n1nry.~ to .an 'f~1npty ~bk1nk.~ ~;tntv,. ena~
U1c nt:·vi: ntode in \"id rnodt

n_e\v vid8o rnodf!. H~ does thiR

~ntriaH:llng

1-,

.NoLice thbt the video n1;,,;rnory bt i_Jf~an2d after tl'u·~ iTH_.HJ.e i~ inihalizcrL '"J'his L~
tHJCaLst::. e21cJ1 inodc en.-ibh_'!s only cr~rt:u.in sections of ·video trH':.'.t11\:)ry.

'l'he- fnncti.on_ scr(-~en t-;:11 ~~n3:b~es or rlisabte~ the vh·leo output ;1.~ indicated
parameter
This- is dorw
rnnt.w!
H_

set_mode()

£t!i;9

tile mod~ as indi.~ated. clears the scre~n and

a~to

th~

the

current viden mode fl.ag

I• deeir@d mode *I

int
{

~id mod~~

p:r:_i. _,..

d.~o,ie;

get_mod~_ p(~-·~;n_rJdr),

mode_inl.t(d_rnode)~

<:ltJUl

g~t
ik

.rid_me?1();

tell ~orl{t what DPW mod~ ia

pointer to vjdec Hiode table :!./

disaLle dinpJ.ay & initialize mode
1~ cl.e•~ screen •/
!• en•ble the display •!

}

~~reen_on()

int

enabl~s u~

disables tbP rlleplay

flag;

~pmt

puinter to video ~ode tabl~ *;.

J..E(fl~g)

f
}JP\'t

get:_mo~:h_'._,p(~1id _~;inde);

ou~p{GTR~ __ ,REG5l

p~t

>crb

else outp tCTR.L ... aEGB" 0)

7- fi2

~et

poin·Ler to video ITTi)dB table
~~~ H enable~ di~pl8y

~ontl-uJ

1~·

all hi.ts 0ff w111 dtsablB

-~!

The hmctfon d<'ar nu.f rw·111 initializes viderJ memory to a v11lue apprupriato for
the current mode. '!'hat- is, in text modes the i.·lrnractcr byte is set: to a span~
drnnicter and the uttribute hvte is set to medium intensity whit<' foreground
and a blaf'k b<ickgrmmd. Fnr graphics modes, the 1:olor bits are set tn wro
!bl<ick/, Only the oddre%able vidcn memory is initialized,

Notice that the pointer to video memory is declared ns a pointer to an integer,
The video memory data bus is n hill 1 ll·hit lHl!:'- Uecause text, mode utilizes a
charnder and at.tribute byte pair :md graphics mode values are all z:en>. it: ioi
appropriate to t<1ke advantage of the lfr-bit data bus. Also. the rwrrmd storago
for an intf;ger is low byte first and high byte second.
The scan page size is srmdfied in hvtes. To cakulate the correct nwmory size,
the 1.1umJit:r ot scan pages is tnnltiplied by half of t.he scan page size,

/•

clear_vid_mem() baaed on the current mode. video memory le ~laared
ta epacea or NULLa. The size of memory ta clear

/·c

is <:ai.culated from th<; mode t.able

•J

c.lear_vid~~em()

{

/;.,,. loop -controJ

t-/

/t pointer to video memory +/
!• pointer ta video mode table ~;

M_ TABU: 'prnt -

get_made_p(vid_mode);
(int Car •)pmt >base;
113 ze '' p:rct· >n!!p ·! (pmt <'f!fH! >> 1):
swi tdi ( 11 id __r:mde)

* ptr to current mode data +/
/* ptr to atart af video mem •/
number of integers to init •/
!· text or graphics mode 7 • /

{
casf' O·

text modes initjalized to ~!

case l :

!•

o:..::aee 2

case 3 :
while(eiza--J
break:

~pvm++ ~

Ox0720;

•pvm~+

(h0000;

defauH-

wbile(aize· -)
breaK;

a apace character with •I
medi.um J_ntenei.tv *;

write char & attribute */

f">J'

graphi-:a mod<'s, jusl "-'
set all bits off t/

}
}

Video Controller , Programming Exampl1>

~like· :~ picture fr~;rr~~·:} ~7t. I.hi~~ t)Xt"£"{·:\nH::; n'.· Lb~:: s.::n·:~·.:~n ..~ t: fb-·:~::t (i!·:~~kh.~~ ~-!''h~~~t-h~::.""
i.r.'.lOdc ia a. tt'-Xt. rrL·K:h.; \Jr ~-~
rL.c.:d<~~. f~·{r·: tf::•-J_. ~·.:::1!~d.e~ ~t. tf;~T~~~~,.re~~ ~~!":':'.:: r(:i;;,

_/\ f~(~r tJh~- p.nr:~('.1-n ~f~
;~~-Lrr~::nt ~,'.id.,:o n:".ode. ~-~~Jd~ ,_-,

Ch(-".J.

{

-:'.,1T(c_:0L _.
d~.~1? ..-~(;:·o~

i~ul

cr;.';.s

:.cl" ··:rz,,

1 . 'P",

= ( c n 1 i~ ~ s ti:-~- ~n :_ prr1) )

col

~:::ot+•-}

~tt;;:-~;
& tt:r) ;

~~ite

right aide *;

1w~~d~h1m

i.nd:;t>nrd ty + /

•

i:/!J~, Ji-_• ( -·~'f'-:l)
~!1--,..'

din_p .. -0 \ro-1.:B .7 > l,

O~ff

~t t:.
.rows

>> (8
-"

pr:!t->-1.<~ngth.

p~t··~wid~h

-::pm++

tr),

p~·t->~·bj

/.:!~

f;,""\!.'-t __ h:

!~ ro~n
/"r

fJrnt->(-b1

fer tltie font

("o-ium:.lfl

tbi~

/;-, do a_l}

d·isp_ t(-1r~w, 0,
:f{·rc¥ == 0 ! l 1.uw

1 /

r:ode .:.-./
r:t!'- 1Na

~-tt-r-):

rows

:_._.

/~o.;
/~·

sa'-lf"' t-urr-e-nt font -""'/
Jont is B o: tE z:/

~:e2aa~e

~ente~

p;ri_

Ct.r.l.

meaeag~

~ 1

p:i::-!?~S

:":C:

\C:i".il,;;t

,,;_bi _l~ ( -t'p.rr-_)
d~~J1.t((r0W8
:!>)~::1.--; _}1

+_,

~µmt+,

attr;;

!~de

message ~1

:f cr:..t _J-;, ~

7 - 05

;fht.~

function disp g disp!ay!-1 u -:::b.nract.er Bf. the de-Hired_ Ht\\: Rnd cohJ.nn1 Ior:a,,,
tiun. 1lie, eolnr bit~-~pixe1~ that fornJ the cb.:1racter are ,s,et to value in at-tr, 'Theroutine assun)t:\s: tJH1t it is
rnm1ber of colnr him per

first .scan Hne_ /\..fJ.<:r th(~ sr11n HrvL" has b£en displayed. ~-be t-:c.an Hne. -offset is

incretnented to th~ next ~can pag0. J\ftcr vlrltlng a scan Hnt:; to ench sran pDg·-.;:
thr~ scan line off:c;et. is zc:i.rncd and f,he cons;tunt (;_tf~:er, ts ·frvTernen1ed by th.fl;
h;ngth of one scau ~_ine. T'he acruol
i7':! tbe cr1nstant offset
the sr~an
line off5!et
1'h~

rntddJe tor loop ensures tbat ail
pb-:.el~ f'f the scan Hne are
F·or
t:1 :u:~-cf•i".lf
requires h:nJ.f coior bit.s per pixt?1 or four
p'3r r ha.r[tCtt:r ~c.:Jri lint:;,

t.h{~ 1nt.erior for
shifts the rokff bit
bit is set. the ·~:oior bit attr~bttte iB (){lf.:d i~hJ lhe cotor
of
p••r
ie< detenninetl
the nnrnt~er of cn1or hits. per
the

F"or -f}i..H'h

7 . (JG

Video Crmlroller , Prngrnmming Exvm.µlA!

The nurn.b.:;"r
width by

Drawe a character in graphica mode at the calculated
positimL

:row and <:otnmn

x:egioter unaigned char
unsign~d cha
at.tT:·

~pc;

/t pointer to video mamo1·~ ~1
!< b}t image </
J~ for bit testing
,h b1t count (current) ,,;

umdgned <:bar tar •'pvm:
u.nsign-EHl cha:r bi·

unetgned char bd:
int be!
int Lb<::

f:f-

Lnt ":'3C:rt.n;
long ("~off;

te:rrnina:ting bit count ,,./
/ 4'. <~u:t:rent sca.n 1 ine --.:./

character offset *!
scan line off set *!
/;, mode data

ur1aiKned int s __ off:
•eg!eter M_TAHLE •pmt

get mode_p(~id mode):
c_o.f:f .._~ pm't ->base + (r:o}_ 'i"' pmt->cb)

pmt

get pointer to made table-/

...
/"f' addreBt:\ of J irst byte -; i
{n;•,• + pmt-->•,;i.dth ' l_:font_h / pt:1t- >nsp});
the -,, iont. w / pnrt->cb,
/z. bit i.magA bit count per byte --/

s_.o:ff

scan line cffset */

Cl,

/""': d.o a.11 t3-can 1inea

-.i-/

offse·t by one ~can. lin~
/* reset to fjrst scan page

pc++)

&& scan% pmt~·-nsp ~~ 0)

j·f(~can

{

c_off

i= pmt->wi~~b;

s~o:ff

1 /

I
pv~

- (char far +)(c_off

s __ off +·< p!r<t->spg;
f od bct
(!:'JlO; bd.)
7

n. oft):
/' pt:r to fnnt byt:e of scan
/'· o'.fJse-t to nexJ; sca!l page, for next paas ot:/
I~ Rtart at l~ft most bit/piXB.l ~;

{

OxOO;

:f<Jr(bc

0; be

null bj.t Jmage

tbc: be++, brl >>- 1)

do a byte of acan.

b:i <<:.:» p~rt,-.>cb,
if{>pc & bd) bl

at tr;

shift t)it image by

of color bj.ts

(}r in next bit i!'nage

·1,

}
-~-p'/m t -

bi;

}

Vldeo Contr.'<_1ll1T - Programming Example

7 (ii

{
;~t

far

icg~stBr

)·.pvrr:~

M. TATil~

'P~t

-3)
{
:f~

g~t

~;ointe1·

/'if.· F;~t R:<Jd..t'f<'iHl fJ'f
pv~r1

(:i.n_.t far
(:o\? :-.

·~-) (pmt-·_:~t~·~Sfr:

(p:at-> 11.'idth

,,__><

(cc,l << l)))

tablP

~:h~rra-.:.t~l:

-.v/

~cd~

rhe !\1nctinn .:i}t.:h~-':.-1 St~ts up ~,~JdO:JR \.'Ondjtf(HiB ::rnd ~}'}~e('ntes tht~ ezu:i.rr~ple fj(cj)ffr<~.~n. 'The n~:::·. _~tff rh)inLS ~iTC'.

'-. j_r:h~c ()
i

{

11 Video
Exampl~ 11 }w
"'Fl.
s~1~ct ~ideo modc 11 } ,
11 F2
ln\:~rt lett~Y Es }

....;,""'

'·[

?
B

F4.

DJeplay

{

'!fl.O

F.~tn:tn

'
;-i

.$.4-

ael~~ted
~ii

M:ain

video mode 1'

~t~.rui_·~

{

!'Sele·ct.

V1.dP(~

M1_;.::h~,i:

)-_

2;J

~F'l.

40 ~ 25

Text~i

•q.;-2_

B~)

Tt;:~·:·tH

{

2t1

{

-r

{

8
g

2•i

{

{ 10
i
i1
'2
{ j3
{ 1 4_
,.
0

x :?S

200 x 16-color'
..
'<'.' 2-co --LO!
}
1

2
21j
'
2ti ''Fl.
2-1

Hfh

24
:? (l

~ 1 F9,

·~ fi. J 0

i:.~

:f_

640

20:1
20fi

400 x

4 c 0 lor·'~ }
.-:. ,.,.. 0 Ji.H:,~' )

fi:!Q )~ ·i.00
4 '· (' l o-r-11 __;.!. '
,,
P{JC x 2b2
J--c. o 1 () r
R+~t u r:n t c vi dcq tn:,.a:n p l:e '' }

() },

;
~

to held input

tin~

/+, 'to hn}d. UlCfHJ Df"1ect}_on_

int :f;
tnt

~n1stgned

0· /

!& Lemp value for mode ~!

,~ode~
('ht~r

r_,·,._· font(&c:.-: torJtfO] LOJ. Fl'\.LSE

0.<00, 2~6);

tS0·C._r-:..on!.~·~0),

.read at~l fr:n.t r;i:n
J:esot vi.deo mcd-o::•
<l.iHpla.y ·the ~ri dBo m~'"n.u
t, rniJ
ter.mj_n~ted
;* ior~vcr (sec f10)
/·~

d.isJ;_ m~n:n (r::~~id);

/-+~

~hil.n(l)

d~termi.r1c

merv1 selc~tion

=~/

·r-/

1-/
~1

·I

{
1~

rit-c.µ._r~e-nu(rr>i.'if:d},

Jin-e[fr1 .::: get_J,l·~p~:();
::·..;i.~;.~h ( 1 tr;e [OJ}

',, get

seJc~t

v.ideo reode x/

dJ 0piay thP mcde ttH:>n.u

funcr.ion t:ey e;electi<>H '/

bTPak.

-~'.

tu---e-~K;

brt--i-H_k;

O>:·i ! - bl !"__:·ak;
O:<clO:
•:ttFH" FB.
~as~

m_t'ld~

F9- made

-: -" Oxfi1

Oxd2:

Y-_, 1 ~· ___ f:::;nt·:~&-~-}ty_e-ro1

b1 <>;,;z:
tn-~.tll.;:;

b1·ea~,

TR\JE,

'E'

8<'1,_~~:,cdie (3);
tn:-~0k.

made

tl1e desired ~!od~
screen extremea

reec~

ftt: !_; .. f!!:')<l~~ c~.t6e};

borrl~:1- (l'fo~ 1 ')

whil~(l}

~f(get_k0y(lc)

while(!) jf{g~t. ~pyfkcl

1~
1 ~

writ~

-:; !!&. c
'.J)

;:.:~

break.

s-et _.J10de ( 3 ~

lette~

ming

(;}

n~t

jR"

bre<1.~::-

vid~o

J·~:

Tet.urn to caller (main m.en.u} *·/

return;
1~ display Lhe rte menu

r_ii..sp_menu(mvid);

Jina[OJ

get_f~ey();

/ .i:

get a function

1".:~:1

for menu ee-lection

*'
*.'

}

Vidcu Coutrnller - Progrnmming Example

7.l

(jhapter 8
K.evboarti .. I11terface Controller
and
"boar(l
-a..,..-

Introduction

Interface to the Keyboard
cnntcuUer ron-u1H.1n.ic::d·.e5~ v/it~h rhe lJ_:..{250
nvnr
Sf"':'.ri<d dara ii:ne, J\ se.c(:~nrl line
$f.-~thtl ch.x:k_ rate. A corn,.
!"Ji::iat~on nf
cind
.;n1 t-he ;:d:riaI cloch line prnvides thie~ corlu11rtni.t:,:2_~
~k~n.s ptrr~:(lCOL 'Tlu_1sc !l.nt-;S are in the.; '-~~~ifed (?_i_bio that c1:)rint!cts tt1£· l.J<Zf10
d -~1n.ti the \; J\)(rn.Bre ':;vork~tatkni.

'rht

;.t h>cfrrf!(~tionui

Logical huerfoce
or

Tlw

n1odc; a__'.] d<tU~ re-c~::~r,.,~-:.d t ·-·~xrn thi;:~ LJ\'2!\0 ke_yboan::l
f~re sti:..1rect in tho n~1tvut bnfft~r "~\·ithcr.Jt. !TH)liifl.car.io.IL !n ts;)n.s:ilt;e rnode, ail <lt:JU1
~n the ran.~-r=-~ OOH·H~)ll ~1nd FOtl au~ tran~'tlatcd t:.o an
or a
lJl(J f'T_/\_L e.:;~<tL:nde:J. ;.;-r·an code {l.nd Bt/)f!!-!d in th~ output buffru· ..Bit ~) r)f the
control·

NOTE
l1urinu.: the systern po\·Verup initi::diz-Pt.inn~ the HJ)t\'l BH)S ~ets
the

d-int0rh1~'.i) f;ontroHer

b> transl:1te iTiorJe. ·rher0ft1re,

Control Functions
The keyboHrd·intertace controlfor pertonns some cont.roi and status functions
that <ire unrelated to LK.250 keyboard operation. Therefore the keyboardinterfoce r'.ontroiler has two H-bit ports. port l <1nd port 2. that are in the.
keyboard-interface controller 110 address space. Commands are available that.
instruct the keybnard-interfoce controller to read port l and rPad or write port
2. Tho;;e commands om disr.:ussed in the command register sectfou. Tab!.f, 8·l
deHnes Um port bits and ·rable 8-2 defines the port 2 bit.s.
Tabfo >n

Port

Bit

Descrir;tion

BJt. Definiti.1ms

ti ndeflned

Always 0

5 -·~

U ndefim;d

EXPANSION BOX INSTALLED
0 .:o· Expansion box. installed
l = Expansion box not in.stalled

IlAJ\l OPTION INSTALLED
0 =-~ RAM option installed
1 -"'"' HAl\:I option not inst.alled
0

HAJVI OPTION EHHOR
HAM option parity error
·; ::c·
No error

{) .·.cc

.Keylmard Interface Con trollei- · Hurdwnre DescdpHon

8- :J

l{eyboa:rd~lnterface Controller Registers

D;;ata Register !,0060H)

r ---,-1

f ------·

T-~--

,--

DATA

1
l

7~0

FV\V ·rbo t:Pt: n'.ddf; rn" \Yritcs this 1J.o:n:. t,r,

dat~.

wi.tl1 thr--

c!);Ytfolier

Conunand
0

·--~~----~~------

~rhr, (_-:P~. ·
•'(~f.:;~;,:te:,

v"Tit:t:s ~.J;;e

Status Register (00G,1H)

PA.fUTY EHHOR
0 _,
.

.l.

controHer serial ('OnHnunica~

The

V\ilwn darn from the

t1nns
t(·tin0
dc:1n

ReaJing the

fU';(T:rvi: 'H~"tF;(YCT

n
1 :::o

_No ~€~c.:~i\-Te tirnenut crr...-1r
./\n 111-J.:.n:.Jgn~~s t1·ansrni~~~ina frorE the
plet:cd ·""vitJ1:1_n 2 rns,

XI\tJ~r 'Tll\!lt~()~ I'f

]~:-·0r1s:11i.t

;Tin. eGllt
0 ..

I~ o tra n.srn it t: rn-t~ou t: error

,£!,.d'.i

transn1ission ft'Orn tht_;
k~~~,:honrd vn1.~

not

']'!Jis hir is also u~e({ ;.n C(.irnblna:tion ,~,,.£d1 t.~-1e prn-ity f':ff()f hit nr th.~;
:·~~c•::ive

U1nef1'Ut bif: ~t} (~sr:i.1b1Ll)b t.~.ddit.innol !/~rr()r con.ditior:r-: f-tS

f(J!f()V:_:5•

cornpletes ~'rt,hin ::~ r:1s, bnt
~)v::, reSJ)t'n;_;;;~J- fror!1

s not rt:Cfdv·ed ~vithin 20 rn~~
the:--~ the tt,-_tE~r:·:~t ?_nd tece:\te tin-~(~O~J: hits ~J:-f; ~tf':.t tD [.
thE!

Bit

R:Vi Description (Status Register - contj

Kr::YBRD INH!HIT SV\.'ITCH - Keyboard lnhibit Switch
0
Kevboard is inhibited ilockcdi
l "" Keyboard is adive (unlocked!

The VAXmaw workstation does not have a keyboard ioch. so this
bit ls al.ways set to l.
R

COMM;\ ND!OAT A
Of the ptdr (0060H:0064H1, the last. J/O write was to the
data register, at l!O ;.1rldress 0060lL
l -- Of the pair mOHOH/0064HL the last 110 write was to the
command register, at !10 address 0064H,

I) .,..

Thi.s bit. is used interna !k hv the kevlxiard·-interfoce rnntrollcr. it
determines whether the bvte in the 'Levboard-inlerfoce controllers
input buffer is a cormnand or data.
"
SYSTEM f'Lt\G

0 -

ROM BIOS should execute a normal powernp initialiwtion

virtual protected mode task request to reset. the CPU to
real I!lO{k

The HOP.I BlOS interprets the state of the system flag t(! determine the rca»on the V:\Xnwte CPU reset pin was toggled, H the
systt>rn flag is Sc't, the VAXrm1t.e CPU i!:i returning to real nwde
from virtual protected mode, Otherwis~', the R.OM BIOS execute;;;
a niJrmai pnwernp initi;iliwtion proo~S.'i,

During rh!~ keybortrd-interfoee controllers pmverup initlaliz,adon sequencP t.!w keyb<J<Hd-interfnce rontrolier dears the system flag- to

the f;vstem

irtst~udiun bv

i.<; a hNo st,;p prnces<J' Issue a

tlHi value OOG!H I to the
at LO addre«s 'oo64H.
write-1:omn:wnd·bvte
i.nst.rnctlon is dhcussed in detail later ln this drnpter.
·
\Vrit\ the vm1m;md
to the iniJUt data
ar !fO w:Jdre;;<e
0060H. The svstt>m
rnfle•:ts H;,. valne nJ
'2 of the r:omrnond
If hit 2 ~if the command byt<c is set to 1. sn is the sy:;tem
When hit. !•; 0, tho~ syst01'n flag is dea.nc•d t.•' ()
0

c.c~n~.J oih~r
}{.t-:~yl~c~~n::-h:te.d ar(1 cf~r.1rrolle1

t-_h2 t. h;.1~~ not bef:n pr.::1cc.::~sed
co11t.rnHe,,-.
COIJtroJle-tr;
~:.he sta.tus (~f ~J?.c· inpv.t. daL::-1

:r;~~tin_I! gb 1)L~./ t.:\;;' kc"t~b.r;~;xd--i:1JJ~rfa~:~-~

C(:i.n!:.r:.:;Ht:r ?.:v:{

{~ 0.J ;·10~: cH:...t:=;~ ;:~n. jqf_,,'-:•:-r'JOt.. Ti·i;:~ .")~f!.::::.i& oT~::-;st_:$jl (.;~~n b~~ r:o::(rci g~_t

Cmnmand Register (00H4H)
.,
l

COMMAND DATA
l

--1---

. j __

(;1>ntrolfor eommmids from the CPU

are instruction:" to the

(;ornn-Htrtd

\';lim'

Com.mm.id
Val.ue

!l0!{-1 FH

COH

2UH

CiH
C2II-CFH

Reserved

HOil

DOH

Read l'nrt :!

f.i JH-,\PH

DJH

\Vnr..e Port 2

D2ll-Dfi'H

AHH

f.OH

Head test

;\(:H

ElH

\Y rite statu"J
r1.:giste.r

C~1 HEFH

HlHFFlI

Puhc output p<Jrt

Read Cmmnand Byte \:!.OH i
Write Command Bvte l{}OH)

'Tht:~ ke}·bo.:-ird-interh1ce..-c.fH.1troHer ha~ an
stored conirnand bvte Lht1t
bow' th0 intettace Cf}ntroHcr resprind.~i to v.;_:;xio~.~:':~ ccurditii)ns. l l1t ~~.~\(:
cc1n1n1<u1ds, read c/nnn-1;1rHi byte nnd \VdtQ co1nrnA.nd byte, pro ..~··idr: accer.;~; to
that ro~tlrnand
t~ontroUer r-eceivf·~ n (e~)d

dt'terrnin,~s

-::.un1 in;~P.r:l.

~~trff,_~d -conu1il'!J1d Uyte ln th;:_~

t.)utnnt. buffer. v~/hcn the
f'.f}nun.axHi. !.t YCf1re~~- the n<:xt dn.t~1

written ro the
to the inh)rn~qUv· stoced 1.:1}lnrnsnd byte.~ 'r.ubk3
b!ts.

IV",;V

Sf~iin

Codt:

O ~

Th~·

sit~n

Tb:;

R..·\V

'Th·n
cnntrnH-sr disables !~he
the c:l_ccl..: ~.ine tc; ;j kH-v st.at~5. ~fhis bit 1~
1\·ri1.in!{ 1.1K:'.~fi1J

;J.ddress {J(i-~)0 rr'
l.Dhib.it ::;:--1Y'it-ch (•nab1ed tsee status
tn.b.ihit S\vh_::--h disablr~d and h~t:~

b:i:: 4L

T1Jbl.e 8-4
B.it

R.1\\"

Co.mnwnd Byte Bit. Defoiit.inus (cont,!
Dd'ini.tion

Hi\V
(l

Flag
HOl'd BIOS should execute' a nnrrnnl powernp initilllizatfon
prm·ess
,\ virtual protP<'tPd mode wsk n'!quest t.n reset the CPU to
real mode

The ROM BIOS interprets the state of the system flag to detei· ..
mlne tbe reasnn the VAXnrnte C~PU res(•t pin wus toggled. lf the
system flag is set, the VAXnwte CPU is returning to ~:ea! rnr>l'k
fnim virtual protected mode. Otherwise, the ROM BlOS execmes
:1 normal powerup initializat.ion process
During the keyhoanHnterfilce contrnll•:rs powenip initializ;-ition se-

quence. tlw keyboaHl-interface crmtrn!ler rh.~ars the system fl<ig- to

Sec the statu-" register bit 2 desai.ption_

n;w
0

H/\-V

0
Enable Output Buffer-Full Interrupt
fl
controller dow, not generate interrupts to
the CPU
=-- \Vhcn the keyboard,intcrfrwc controller places dat<• in the
ontput buffer, the kevboard-interhice controll('f g-em?r<•tes an
interrupt to the VA)i"mate CPU,
,

Keyboard-!nt1;rf<11'!; Controller - Hardwan: Dc'scription

SP~f-'rr:o?:~t
·rhi:~

Lio\./\ 11;

co•"'!.;r•iar:d .:-:;:J'._·~5-._':f; th~·:;
~f'h.·-~ s_~~·::.;t.t_):-TL fl~Jg ~~-UJtil&.
~ t~·;;u I:::; r;::::de~~ )-::~

f;f;H

h>n:;d HO~; ';'">eri;''"''·
H;\M h;:;r foiHJ1

In~e~~f~1f~e 'feL~~ f/·} fl.ti)
Tl~i~ t":<Jrr-i1~'l•]t1d cr:.11~;·~~ t~-i~~;
Lr~~?~~(;

:T~sult j---~-:;dp;_~ ·~2.
-v

tl>:: c1=..!t.r•;.JL ~JL.Uer

i.:u.H
OJH

\Jo ~:rrnr.::: ::~::::t{~Cted
Li~2i-~~;
fl-.-1~~k

o·~;;i

nH
\)'1fl

f,:!IHble f{t_yhc~.a~·d i./~.i~fi~
·:·i;_~·· --€-'Hl~L:!.Ld ("{Cjc .:-

!..n-t 4 o: tn<-

:nteff'.i··"'

rh,,
"·:!f;Ci.:; ii~ i:::.

~-~·..-:f:pition:::-

s-~:-~-: T;-~.~-Hc

•.-.-~;:-~nn~tn.d. -~-:h(~~.i'.(j

k- 12

g_,. }j~·;•·;1~J~e i~ cvcr-;,·.,,-tiU::_.;; ~n~-y· d:~t!:~ i:.1

-iut bf:-: :..;..so:•\: t:.qic-~:~; ~-fL:: ,:1ut;;~).t h'--lt:,~r l_s nn::pty

-i-~tbh-;

8~1.,

Bet'.I.Htse it u·v(;rvvTitcs auy d~~ta in the huftt:r, this cornrnand f,b~._;i..d.d

fH:Jt h$'_; "t~ed unfr-.s::~ th.t; (H_~tput buffer is en.1pt,'i·

-rh1~
cnn~roI!cr n-~ad.'i port 2 !hits 7·0} f\n(-1 p·ial'."es: b!ts i' 0- i_n
t):H.: !)U.tput hnfh.:r, Ferr pnr~. :2 bit. rh-~finh:ions. sr·e 'fal.)_lf~ S~2. J.lf'c;.1urse· it o\--t!r~
1

'Ni-itJ::s ~;r.r-,, data ~n rh(-; b-uf-fer, t.bi~ (•_:~rnrnand "Shc;1}d not~ b+; tL'ied ug}f:~s the·
!s (~r:)pty,

on·~r.tut. b:.xf.ft~r

Write Port 2 !Olm
The
in.Ott~~

\-g:-erfHCt'. ('.(Jn.~.rnilf~!'.'

CAUTlO'\
Bit 0 ~.:if

f.n·ntroHer outp'Jt pnrt. i l~, r~.(~flnf'Ct1':;d_
to ;~:br'. \/1~1Xrn;~1t.t: {·PU ff.~Set
(:·k~~nin~ bit 0 t•J £i 7:f'f\l

Read Test Input'CJ iEOH)
Tthe
contr.-.)lh-::r n:-fH:l~ its 'TO and 'T-1
;:~nd pLhtes th~:~
r1atH in thr:. (}Utput buffer. 'fh:l~ con)J.nand \vdh~~ over n.ny dat~J in thf,;· output

b1_d.hn-- r..h,)t l.Ht~ not bi~t;l1 reHd
the (:PlJ. Bit 0
and bit
c.orn.:~s~Ka1d:9 to the stt:rtc of T 1.

\trite
T'-,;s iH

crn rr:.roHeY ta kt~s bits '7 . ~
\\-' f i ~-CS tb::.~::"fi tf1

uf the

Pulse \)utput Port IFOH-FFJH

this con1nu~rH.l 1 hut ~-.d.ts ;~-~:: nre ti,:.it- c-~Tnn("}_',~.(·_~d
th4:_; addn?,ss line 1\~!o . Bit- n i"~ rnrn~e:cte·d ·t.n l:he
HfHVI BlCJS ;. 1 s.{~s this cornrn:J:r<d to ret.;?ffi

l\H four hitf~ L1~(il an" .a-ffes:tc·.d

l1it

f£2;t(~~

\T/\Xn.-H1te (~Pt) n~,;;:~:t

nindo.'.

Keyhoai·d·lnterfl':u.:e Controller Error Handling
~nit.iat.J.::~ a t-ra..nsn1issi-on scc..iuencc and th~ data ls n_~""'
th~::
~ntcrf;:H~-c cnntri.:.>licr !.ssu~~s a n::sct1d

:·:(ri1·l1na;ui lf the respnr.s~ Ln the res-end cunnn.iHtd i~ bad. the
i.Fh.~~-fd_-;.,.~-e controller p1sces ::tu FFJI f~od1~ in the output hutft;r and ~cts the
erro~- bit in t:b.e sta~ lLS
If the ket,.rboard-ir:t.f~rfarf: c•JatrrJHer (·.eru1ot. f~tart a tr~_HtSH1iss.lon t).~i_t.bin 16 n~!Hi'"'
,:r..·ithi_n tv,,·(} rriilU:St:;condB ~dt>.:;r fr
v~·as ~;;tat tt:d, ttH-~ tn::-1nsn~lt- ti1n~out bit is r1et tr~ th~ staLu;;
nnd an F.EI-f.
~-1{::'.COt1d~ or 11-, c.:1~tnot c•nnplet.e ~l Ln-n'1srnL~ston

If th~ L,J'(_-_2ft0 ktybr);;~rd does w~<1t re.sp•Onf_i \.\'~thin 20 rniHLst•f)')lH:is~ then tht.'.
~r~inscnit tln~.r:o:Jt bit. and receive- t.in~.C('HJ.t hir. art~ .".-:;~~t ;n the status
rfj:·:;po~v-.::+_~ \'<:,·as ~ect:i-~-'ed vd_t.r-i a ytldty \:?rror_ then ~.he
error bit nre set. i.u the Btat"t;s
c:nd
c;n FLH
i~~ ptrtced in tb<' Cnitp11~, buffl1t:

thr-

cuntro~ler.

LK.250 Ke:vboard
•..
Scan Codes
When key is pressed. the Lh2rio keybo;ud trnnsmits a vniue. in the range
0 l H·9DH. that identifies the pressed
This value is known as a sca11 eode.
It rhe
i.s held down for 11 time that exrN?ds the autorepeat delay time. the
keyhoHrrl rqwated!y trnnsrnit~: the sean <;rxle 11t the autorepeat rate. \Vhen a
key is released. the Ll~250 keyboard transmits a release rode of FOH foliowcd
the snin code of the released ke_v.

transinits scan codes t«J the keyboard-interhicc controller.
ccmtro!tN is in pas,; through mude. the
interface ':oni.rnih:r transmits the scan code or release eode (FOHi ami suu1
code without conversion. H the keybonrd·intcdace C(.tntn•Her is in t.ranslat:c
mrKle. th<:• kPVbfJard-intcrfacc controllPr conFerts the Ll\260 scan code or re·
lease codt.: WiH~! mui scan code to nn i11dustry·Mnndard 1 ·hyte v<ilue. In the
industry-sr.anclard t»'pn~.scntai.ion, a nJeu;;ed key i~ .indicated hy 11dding 8011 to
the tr-ansb-J.tcd sc;:1n C(1dc \·alue. ·
if the

TahlP tHl lists the LK~~50 scan codes. their equivalent keyboard·interfacecont.ro!ler i:rarn>lated industry-standard v?1h1P. and keyboard location labeL
LK2f10 keyboard. shows locadon labels for

Tabk iH> li;,r:;; values in the scan codl? range !O I H-9BH) that the LK2[,()
board dot>s not use to repre!>ent kevs. HowcvN. ill tr:.insfate mode. the
controller translates thern to the indiu1tNt indnstry·standard

K~·yboard-Inforfoce Control!t·r · }forrlware De<:criptiun

l~ ~·1
I

L~2.J

LK:CfHl

Keyboard

SCH!)

Position

Cn(\c
OIH
ChH
04JJ

4:3H
TFH
;}Dii

cn::i

o;)H
OGH
OflH

:rnH

0Cl9

:1CH

GOO

01\fI

44.H
42H

007

OBE-i

40H.

('t-06

O(l!.-t

:\E:H
OFH
2PH

(102
1JOO

lDH
.LOH.

C!Yl

ODH
OE~lf

J2H
l.4H
l.~H

;;H
i :'\.I-{

(Hlfi

GO!

(}09

Tnb

HOO
H9H

Ctd

02ll
:2C!-1
1 Ff-l

('. (! J

; i lJ
OdH

DG2
C02

iv \V.
2

21 H
".22l1
dD

':OU
·~H

?./\ t·f
~~.bH

l),)jl

r.:u.-i

O,tf.·1.

LOl
HU-:!
Cf:4

l<f'yhoard
d

P{);iitim1

D04
illiH

EfJf~

;{If[

HO<)

'';;:II

;~Olf

B-l_}f,i,

b B

(.''.06

cor~

}{

07"?-~

:~A.H

r H

J)OG
FOG

JI (~
-

c_~1

r Y
~>

32}1
{"'0'1

~i('..FI

D07
E~07

;H:;;H
'1lH
.f 2 t·t
·~ ~-1-~j

nqH

!~OS

f$0S

·~ •:i

•-'·f}t

COE~

IiH

!)Og

k k:"
. r
I

•

.LtOH

44 ll

r;1n

~:'H

a41-1

BO!-!

E\1 . 0

4A!l
4bl l

(:(}5)
(.'. 11)
Lt.~_,:)

oc-h

E i.1

r; :2 ~.- i

;;4H

i '.

cuo
1i

Cla

!\~~I-~

L~ ~ ~:

~-:;.:<..\

Table 8·5

LK250 Scan Codes mid lndu;;try·Standard Eqnivaleot Value knnU

LK2il0
Scan
Cude

Tn1m;IRted

Industrv-St:;rndurd
Scan Cil<le

r,DH

2BII

GU!l

UEH

69lf

,!FJI
4B!.l

HRH
HCH
70!I
THJ
72H

Keyboard
PosithJn
E l.2
EL!
B20
C20

47H

D20

fi2H

A20
•\22
B21

5:.1H
fiOH

Key Nmne

Delete IViord.iCbarl
l End
4 Left-Arrow
7 Horne
0 Ins

Del
:!. Do>vn·Arrow

?aH

4CH

C2l

7-1H
7f,H
7GH

4DH
48H
O!.H

('??

77H
79t1

4f;H
4EH
'il.H
4/\.H

7AH

7CH
7DFf
7F;H
7FH

P'.'.l

6 Hight·J\rrow
fl Up Arrow

E20

I!:fi~~

NumLork

(';!,:~

+ ~Kc.vpa.d.l

B22
n2;3

'l7B

E23

4!lll

IJ'22

4flH
f•4 ll

,,.._,.;..
E'l''

4 lH

(i(l!j

54H
!)!)ti

G'.:U
L lG

;'!l\H

EI 7

Pi.rDn
\tfoypad)

PrtSc *

9 PgUp
ScrlLor:k nreak
SysH'Xl {i\lt/F~?O~

WlH
84H
8f1 ll
.')i)H

H7H.
881-I.

57H

E18

Henwye

f1RH

Pl.G
Dl7
Dl8

Select
Pre;,

t:~~t-1

fi~'H

8AH

~)/\H

SBH

:,mI

g(;}-{

C1CH

8DH

··,nH

8EH

FiVH

C17
BJ 6
Bl.7

BIB

• 1

F20
Find
l nsert Here

Next
Left.-_A.rrffl'..'
D(>Wn·Arn,v:

?FU
~~ _'. ;1"!
n. lI
!) ~-~ 1-~

lil'i

1:2n

("i: -~- ~-\

GL<!

~~-'~ i-~

(~ t: ·i--~

Fl':

L
H

Unu;;;,,d

Vnm;NJ

Sorn

Senn

f{oiJ,f3

Code

Sc an c;'irl"

r,J H

73H
7·!H
c);;n
6EH

fiCH
f:eEtt
:'>FH
HOH

7bH
iUH
itlH
6f)J-:t

GiH
fi2lf
fi:lH
f;4H

Ci,()}-.i

i:J:JFI

7,\H

4 ._i r1

O;H
08H

58fl

70H

6/\l·l
t.iGlj

lfU

H7H
2'iH

G('!·I

P';i t-f
r:~ J:~ 1r_

Tnms!ah:<l
l.nd1t,.trv·Standard

7'1H
7~)ll

I) 7 i I

7BEJ

HRH
G:\H

7CH

7DH

DDH
~~FF!

;.rir

·*OI l

GBtf

~rH

•Li ii

bCH

'Fil

'i.J H.

GEH

'7FH

tiFH
7HH

tWU

b'.<)fT
8UI
82H

80H
H'H
B:ffl

;',Jil

LK250 Keyboard Command Codes
Table 1'"7
a summary uf the LK2~10 conunand codes. F>'illo'l·ing Table
8·7 are descriptions of each conunarnJ Tlw •:ommand description»
the pnr·
pt:se of tlw cnmm;:mcL the ;:ictions taken
t.he keybom.·d. «nd th<:; res;Kmse
code cransmitted by rhc LE~:)() keyho:ird. Tbe LK2fifl
n'spo11sf' codes
arc described Jntel in this chapter,
Table 8· 7

LK250 Kcyhom:d Cnmn;an<l CodPs
Destripi.i(ID

(H)ffAAH

l.nvalid Cnrnn-iands
ID lDig!ta! Lxt~Tidedl

AilH
'\CH

Ent.Pr [)igitJl Extended Sum Code .M.ode

ADH

Exit:

Ex.tended Scon Code l\foJe

Set

LED {Digital Externfodt

AFH

Ht~sd

Kevboard LED

HOH

Vri!mne 1D[gitnl ExtendetU

BIH
B:.'H

Dis uh le

BHI

fvhde t:nlock

F.DH

Lf.fJ<; On 10ff

EEH

Echo·

l::fH,F:?H

F4H
Ff\H

FtlH
F7H-FDH
FEH

Hesend

FFH

Con!rnllc.r "Hardware Desrriptfon

Invalid Commands tOOH-AAHI
\'V!wn the LI\21\0 kevhoard rcceivf:s a code in Uw range OOH-;\AH. it trnnsmits
a resend request. Tlw Ll\:2[10 keyhoard <loes not transmit an <1cknowledgc
\ACK! fnr code<; in this nrnge.

Hequel'it. Keyboard JD (ABH}
D!CUTAL Extended
VI/hen the LK2'>0 keyboard nireivcs the code ABlL I.he keyboard de11rs its
output buffer and transmits a 2-byte rnspons<!. that identifies tbc ver'>ion nnd
mi.x!e of rhc LK2f10 kevboard. The firnt byte returned is the v~'rsion number.
The s;_ceond byte is the current opcrnting mode, OJ IJ fnr industry-st.ondard
mode or 02H for .fl!OITI\L cv.tended mo<fo.
Tu
execute this command, the keyboard-interface contrnll(~r must.
be in pa1>s·t.hrough mode. Otlv~rwise. the keyboard controller attempts to
tran~!ate tbe rlat~1 to an industry-standard scall code.
Tlw LK:?'JO keyboard dues not transmit nn ackncrwledge V\Cl'Cl for thit<

command.

Enter DIGITAL Extended Scan Code Mode (ACH)
DlOJTAL E'xl<c:11dq!

\V!wn Jhe I.JC2°i0 keyboard receives Lhe code ACH. the keyboard enables
DIGITAL ext.ended mode. turns otf LCD #4, and trnusmits an acknowledge
cAJ'.E•.

Exit DIGITAL Extended Scan Code Mode !!\DH>
l!f(!ll'.AL Extended
vVhcn the U\2f:d) keyboard receive~ the end(' /\DfL the keybo11rd enables
industry·standard mode, trn·ns on I.ED #4, nnd tra11smib rm ackno1.vlcdge
t;\(l<i.

In thi'i modi~. only industry·sta ndnrd snrn i~odes are genernted.

Set Keyboard LED iAEHI
DJG11AL E.rte11ded
\VlH:n !hte l.E2GO keyhoarrl n'ceivc<: the l'odc AEH. thP keyboard turn<; <..Hl LLlJ

'14. and tn.msinits do acknowledge iJ\CF,i, Fnr Ll~Ds l·:i, seP Ll.<.;LJs On/Off
1LDIH.

Kfwbnurd·lll t·erf~1e<• Contr11lh~r

Harthvnrc' Description

8 2'.l

\Vi-~c~

the L~£'~2f;O

~t;··

t~'Bi!E:=.rttfrs

\o\!h•;• :1.,, i,!\'.,'f,0 "''··"'.''"'''°'

?Uto··
cn~<bk:d

I:Ji:sn.!Jlc
J,;f()-l'?>~tI.

Keyhm1nI Mode Lock lBal-IJ
f)l(il'i_.:,l!" l::,:-rte.•J.de(f

VV!uc·n th,c• Ll<'.:M.! keyboard rc<:''ivcs U1P •. ,ode BJH, ti-'"' lrnyboard disables the
(:nrnbin0rinn ;\Ll'/F-.t 7 ~t.nd trctrt~1njts an
~A.C:t~1. ~rhe
corn~

hhwtion ALT/Fi 7

the keybnr1rd between DI<; lT1\L 1,xtern:Icd mode .;md
'T'hi•;
combination is detect<.'d and hand!ed
the
HlOS,

.Keybmud Mode l inlock fB4HI
1Il(:·f1~jlL. f..".t.t(.-~-det...1

\'\/her~.

the Ll(2~J0
r-c{·tdvcSi the (:och.~ fi4Jt the lu::ybo;.ffd enablt:s th~~:
{':rnr'tl1·inabnn .ALT'/F.l 7 ~:Hd transrnH,s ~Hi
{AC'I\.~. ~rhe kf~}·· corn~
binatinn i'\l/f1!"17
the
bcrwe•m DIUJT:\L ·~xLended mode <1nd
ind111'tr.' shrndnrd rnode. This
cnn;blrn•itkm b det•cct'"d and handled
tlw
n<•t ttw RJHvl BfOS. 1\LT'F17 cn:,.b[ed is the defotdt condition.
Re~erved (BGJI.ECW
!}f(_f[T~AI.

E:?xtcnd(_!d

\Vhen the LJ\;2 ~\O kt~"",Iboard !~(;~t:1:·i d;s dl\V o1· ~"i"lfo reserved c.odu.s H~::dl-[( · E--L tht-~
keyboard t.ran$i.T1.its a:n
li\(~1\.i and re~un.H?;j ILs previon~
:<:::L~Jh~.

s 2ti

LEDs On10ff IEDH)
DIGJ1>1L E.t:tenricd
This is a ~?-byte command
ol a •'Omrnand bvt.e alld a value
When the LK~~c,o keyboard receives the code EDH. Hie keyboard stops scm1ning for
tranmnlts an acknowledge iACI(). and waits for tho second byte.
\Vben the L.R'.260 keyboard receives the second
tho keyboiird sets tlle
Lfi:IJs hJ the indicated value, trnnsm.it'J an nd<nnw!fKige IACi<;) and returns t<:•
its prev i.ous
state.
If bit. 7 of the value byte b sBt. w l. the value is intprpn•ted 1ls <i conun.amt
The current commsnd is aborted, the new cornm111id is e·-<e(:uted and the LK2fi0
returns tn the

The bits in the LED valun

{)
•;

('n.p5T ,nck

0
1

CapsLc,d:.: LED off
LED on

O -·
l

NurnLork LED <lff
NumLock L'";fl ou

Scroll Luck
0 =
I '~

Scroll Lock LED off
Scni.li Lock LE;D on

Echo (EE.H)
n'Cel\'cs th>~ code EEH, thi:· keyboard tr-arv;rnits rhe
state. This cmn-

san1e <:cbo code 1.FEf:U f.lnd cuntirn.H~& its
n1.and is <:
toot

Heserved (EFH-P2Hi
VVhen the l.K260
receives ;:my oJ tlw reserv1•d ,·odes EFtl·F2H. the
kevbo;ird n::in.;;mits an ocknowledge (ACI{i 21nd re'.!iumes it;; previous
stute.

S<-t Autorepeat; Dday and Ruie (F3lU
1111iu·;try·S'tandnrd

This is a 2-byte command c1msisting of a command byte and a value byte.
When the LK250 keyboard receives tho rude F3H, the keyboard stops scanning
for keys, transmits an ackn•>wledge lACl\.), and waits for the se<:ond byte.
When the LK2Ml keyboard receives th0 serond byte, the keyboard sets the
autorepeat delay and rate to the indicated values, transmits an acknowledge
I ;\('I\ I rmd returns to its prnviou!'l scanning- stnte.
If bit 'J of the value byte is set to J, the value is interpreted as a command.
The current conunand is aborted, the new command is executed and the LK250
n~!:urns to thn previous scanning £d:nte.

Thi• bite:, in the delay and rate value hyte have the following meanings:
Blt

Dei;;cription

Always 0

fHi

Autorepeat delay ! ± 20% ~

00 C::'
01
JU "'-"
11 "--

4-0

. 2 i) secimd<;
.ii seconds

.7f:i seconds
LO second

Autorepeat rate 1.:t
20('.Ji,}

Bits 4-0

Rate per second

BHs 4-0

00000
00001 -·
fl0010
000!..I

2!Ul8

10000 ,.,
10001

(10100

!9.ft8

00101 "
00110

184fi
17.18
15.9!.i

10011 ...
10100 -lOHH
111110 ·101 U

14.99
1:3. :l 2
1 urn
t0.90

11000 ·11001 ..
JlOlO " '
J l.iHl -

··-~

00111

01000 _..

orno1

0!010 -01011 OJ JOO -01101 -·
O.lUO
OUJl

2\i.6fi
2;1.98
ZLflO

·~

10010

••'

9' !J!l
9.22
8.56

IlJOO

7 . !J9

11111 -

Keybourd·lnterfac~ Cont.roller

--~~

l JlOJ

.,_

l.1110

Rate per second
7.49
fiJHl
f;.OO
f)_45

5.00
4.G l
4.28

4.00
3.7fi
3.B3

:too
~'..1a

2.!JO

VH
2.J 4
2.00

Hardware Desedptfon

R·· 27

outpt1.t buffer-. tn:.n~nnh. ~ an

fnr k~~'f~·

lJs·e o.f t.his co1TtrUH.nri .ossun1es

Anv

~trnkrs thm were

cJt.-~]r-N !ts outptd. biJfh?r. restorl.>$ (~011rHtions to the def(n.:dt p(_r~verup -~t.-at.E:..
transn1its nn
LA(;I<~~ nnd ~A'ait.s f(~r Hd<litionnl cornrnands,
scanning rcrn.ains r!isB.hk';d . .:\.ny key sr:rokes OHLt vvr'.t"e
b'()_t noc
tr~::u1sn1itted nrot~ lo~::L

Dd;.i.v!t

.5 S€C0jH.ts
2!-.L98 ~i~::t Sf!(~'.ftud
l~n~1t1h:d
LEt)~

L);_gita~

Off
extc:nd.ed rncKle

[1is;·1bit,~d.

\.Yhen the LIC2~)0 k.e.vboard rec.eh:e~ t.lie (:Od\:" F5f-L tht~
s;-ops .sc.an.~
c.lears .~ts fHitput hutfec restnn:-;s condition~ t.o thP rietnnh fYliV/en;o t;bit:t:~
tran:-::,n1 its [it1

I:\(;}{} £n1d n:~!iurn.e~ it.~

dt>hrs

. fi sctonds

rute

2fL98 Ot~:r ~ef(rnd

Ew;hh;d

OH
+:xtended rnode

Di4ubted

~-~tnte..

rnceives anv ol tht' reserved codes F7H·FDH. the
{ACK) and resumes its
.'>\:anning

1N?wn tlw LK:2'i0 keylx•ard rt)Ct;ives tiw i:nde F'EH. Um

rnpeatcs its

ln~t i rnnsrnission. "fhiB r:rnnnLu_nd is u~ed \vhen t.ht:- k.evbo~-H,'cl~interf;Jce contsoncr

deteds ;« reception error. It can b+: sent only in response to a t.r;msmbsion
from t.he LK;;c,o kevboan:L
the resen<l t'.omm«nd CFEHi mu:~t lw
rrnnsmii:t•!d bdon; the
controller ailows t.lw
starr annthi;r teansmissinn. If the retrnnsmitted darn i.~ stili bad. the
inv;rfa.;e comroller pltice<> rFH in its output. lmHer and sets the
;-n:d tirncout r:rror :s:tt1.LtLS l::lts.

Reset IFFlH
receives tJK code F.FfL the keyboard trnn'.'mits au
fleci..;ipr.
1ACK! is inrlieated hy reM!ing· the Bdrnowlr:dge \/\CKi frnm
control.let, •.etLing pori .2 bits 7-G ro t. and
them
:wt 1ur «t Ienst 500 .us. \.Vhen die kevbo1H'd
acceptanc0 t•f t.he a<.>
!ACKL the
ln1·nkec: its se!f-wst diagmJstic. On
··ran<;mit.s AAH (self..t.e!'<i. success I or F( :H lselftes'
ri:c;cilt ot r.iw ':idl·t.e;.:t. Lhe keyboard is reset ro dtdmilt n.rr:ditions
output oulfer is ernpry
l;~t·K~ nod

w;.1its for Uw the ackmw:lndg., tu be

Default
Autorept:at dehi}·

rate

. ;:, seconds
'.!B.98 p<:or "''cond
F:nnbled
Off
DisablPd

Keybr)nrd·lnter!'aer• Conirolh:'l' · Hardwar~ Dcscl'ipt.ion

8- 2H

LK250 Keyboard R,t~sponses
to ev1irv tnmsmi0<sio11 sent tn ir. Mo"t (if the
time the

t'\C!-(i, hut ;mme commands have

cmnrnand
T•.~bk 8-8

for details. Table

LK!50 Keyhoanl

fHJH
AAH

E:I::H
F,\H
FCH

FEH

Hesend

lluffor over.run HJOHi
This code trnJic;Jtes th,~~ thr, L·I\:::G.{} keyboard ontput buffer 120 bytes} lrn» been
fiik~d tn
1.19 key r>:)dlf.~~} and an atternpt vvf!~ n1;Hle to store another
eodc. The 20th code is
with !JOH.
•'oncrot!et' is in translate mod<). the LK250 keyboard
industr_v-f,'.t:-indnrd buffer -overrun

U tbe

huffer~r;:verrun code HOtJ ~~i trH_nsiai:(~d tu ~n)
f'(Jrh~-=-- t:Jf

Thi~:

f' FJ-l.

code ~n<l'i1..:ab:_-~t~ ~ut.rt.:.~ssfu~ t...::rnnpiet.h.n1 of the· Lf\2fi0
seit-re:St. dLag~
m:e invoked ns part ot the pmverup sequence
the reset C(Hnrnand. ~Ft"'!rn.

nust:ws TfK sdf.id;t.
Hr~d

r.fhis code jndic~Jf:cs
of ~~n echo cornn1:.~nd CE-Ell!. In res-;pr}nSf1 to an et~ho
cmnmand WEHi, the l,!';250 trnmaults £rho !Ef.Hr iniitead of o.ckn(lwledge
U\CKl (FAflL

Release Prefix (FOHi
1ndn.c;try·Stafl.{.fonl

This rod': indi.ca.tes that a key w<is releiised. lt is followed by the scan code •>f
the released key.
!f the lwybnard·interfoce cont.roller is in t.ranslate mode. this !":>byte sequence is
tramdatcd to an industry-standard l·byte release code by n<lding 80H to tlrn

transl.med sea n co<le.

Acknowledge IACKI iF AH}
lndHstry-Sta 11 dard
This code is trnnsmittcd by the LK2:)0 keyhuard in respon,c;e tn most of the
valid i:-nmmnnds. Some cormnands have special responses. For exmnple, rnquest
keyboard identifi.catinn IABHL echo (BEHi. and rei-;end iFEHL For additional
infornwtion. see the descriptions of the LK2fi{) keyboard conunands.

Self-Test l<'ailure (.FCH>
This cnde transmitted by the LK2C10 keyboard tu indicate Lhat a keyboard com,
pc>nent. foUed the self-test diagnostics. Selt·test: l.s invoked during the powerup
sequence and the reset command IFFH!.

This code is trnnsmitted by the LH.250 keyboard in response to a keyboard·
interface control.lcr tnmsmission containing a 1n1rlty error. Providing that the
lust fr:rnsmlssion tn the keyboard was not a resend command (F~jH!. the kev·
bonrd lnterrnpt handler shonld retransmit the l11$t keyboard command.

LK250 Keyboard Error Handling
lt the L1\2f•O keyboard receives an invalid command or a parity error. it replies
with <• resend command.

U.S. and Foreign Keyboards
The LK250 keyboard is shipped with key fogcnds appropriate for thP dest.ination country. Figure 8·2 through Figure 8·lf1 show the ke,v legends for the
various country keyboards

Kcyhoard-Interfarc Crmtroller - Hardwure De,se.ription

8- :u

Figure 8-;)

Pinn.ish Keyboard

Keyhoanl·Jnterfoce Controller

Hnrdwn.re Description

8- 35

Figure 8-H

Hehn>w Keyboard

Figure 8·11

Norwegian Keyboo.rd

Keyboard·Interfaee Controller · Hardware Description

8-· 41

Controller · Hanl.wnr•e

Figure 8-13

Swedish Keyboard

Keyboard-Interface Controller · Hardware Description

Programrning Exan1ple
The Rubnmtines in the keyhonrcl exomple provide keyboard input sappi;irt for an
of thP exarr1ptes in this rnamwL The keyboard example demonstrat1";:
..
•

Communicating wi.th the
The use of kfoVbo;ird translation iablAs
Extended features nf the LK250
('t\lJTfON

ur irnproper operation of this device r.an

fmpnrper

f:ause thf' \/A.)Cn1::.tLe \.Vorkstation to inaHuncr.ion. Thie scope of
the
is limited to the c(JntPxt provicfod in

this rrnmuaL No other use i'> intended,
rou.t-inet~

as described in the;

Wrltcs <l command byte to t,he kt:ybuard·intNfoce cnnt.rnl!er
Writes ;;i rfota bytr; to the knyhoard-inJ.erface controll»r

pass_tbru
irrit

Pr;:;parAs the interrupt !ltrurtuw for

wr- kvb

buffer for

kyo icd

Turns LEDs on or off an:ordi.ng tu rhe knyboar<l st.atP

send

Retrieve~

rest.

R!',,ton's dw
kcvhoard interrupt. stn:etm'E'
(;ets .n 1
value from the

get: __ key

kyb_ int_ htmd

data from a

buffer and wrirt'S it to th~; keybomd

H.<:lndles kcvboard-interfat.'P·cuntrol!er

St"an code trat1slati(Hl~

kyh exm

PnJ\:"ides an t)X3n1ple- err\..'ironEnent. for
uf tbc keyboard

and perform~

#inc 1 ude "rb. h"

#include "exa'np le .b''

/? define constants and structure& used in keyboard examples

#define COMMAND Ox6•f
#d.ef i ne DATAREG Ox60

/* command regint;er in I/O space ,.;:/
j;! dat11 register in 1/0 f1pac:e *I

def in<:> mask bit a for keyboard state flag */

#define s LSHF
#define S_RSHF

07(11
Ox OZ

#def me s CTRL
#defirH'' S_AU
#define s SCRL
#def1ne s tlUM
#define S_CAPS

OxO'l

#define S. INS

Ox80

OxOB
Ox10

Ox20
Ox»O

I* left shift key is pressed */
I• tight shift key is pressed */
,i·*· (:ontrol key is pressed ""'"/
/:t: Alternate key :is pressed *I
/'>' Scroll lock :i." in effect */
/* Numerics lock ie in effect ti
/)"'. Cape lock is in ... Hect -1"/
fci, Ina!:' rt mode is act:tve */

!• define modifier-key values returned by keyboard •/
/''' control li::ey c/

CTRL

Oxtd

#d<lf :ine LS!ff

Ox2a
Ox36

/"' left shift ke:r
/:+ right sh:i ft. key

Ox33

OxS2

alternate kfly ·~/
/ "-~ Lock/Caps Lock key *-)/
/* NumLock key *-/
/":r ScrlLock key ·+:/
/*- lns (Insert) key ~1

Oxf>'..!

/* De) key */

#define

#define RSHF
frd:ef ine ALT
#define CAPS
#define NUML
#define SCRL
If define INS
#define DEL

Ox:'la
Ox4S.

Ox46

4
.,;

• define aome keyboard interface controller cummanda
#def:ine RDCfl

0;.;20

#de Line WRCB

Ox60

/* read command byte :¥./
/;f. write CQlrJn!'l.nd byte */

Keybmird-Interfure Cootrollrr - Programming Example

8 47

~def!~'e

LEDj23

-#k.i·~.! ine ~r:1~

#d~fin~

0~ed

ca~txol

EXT_FXM Ox~d

l~<lc

t~~=

~nd

turn led #4 on *
f• tu~o led W4 off •!
1~

".Jx!tB
-~-

'ent~!. r

/;+:

~xj_-r;

ff'f{ilr.t..,L (~xteudeii kecyboard m~H.i~ "''/
C_fCITid:... eTt>£:ndet!. k~yb~1.i:u.d i'fl(J·de -,,-/
1~

~et

auto-rep~at

••t~v-z~p•ft.l

Tate

set speRker volu~e

/* r~t.11~fi ~~yboar<l IQ and @t"t~
TeRo·t ie;bt~&~d to defnult ~e)ues */

/-J;. ~-:cybaa~d buf:h::x fu1J
~~;:~,1-e-s:r:

!~ dei1.n.~
i~

rGte:

-~-~;

rf:~cnd .::ort.?HHJ.d nr d~ta +/
j ·;,., l-:e~ihr:1~1:d M-:-~~now.lerlg~ --1; ~

some Pt~·i.e d~pen~ert~ k~yboard tab~e ind~x constants ~/
RUM U.(QS ~as B~p~tate alpha anc J11tmeric tRb}eA. ~;

Th~

looJ: 1n normal kev table

l*
#:iefi?:.t~~

T~.CTffL

~J~..:n.+

~dPfjne

!_S~FT

0~05

~"f;-i~finc

T_.iL.f~

0;;!)8

~dcfii1P

KE __ srz

1~e

l* inok Jn -::o:ntr!:Jl krey teblt! i<-/
/·~

look in abift table ~1

/* state of modifier keya t/
/>< last char:acter sent to keyboard
!• place to store incoming kevs r/
/* laet released key for demo ~;
/* last depressed key for demo ~;

uns:i e;n"'d char kyb .. atat.e:
unsigned char J asL send;
unsigned char key .. buffl.2} [KB'"SJZ];
unatgm~d char released;
unsigned diar depr<!ssad;

I* :ring buf-fe-r co:nt1~ol atrut~ture J::/
!• ring buffer control structure •/

RJNG ... BUFF ki.j:b;

RING.JllWF ko_rb

d<>fin"

the keyboaxd tab las ,;./

Note: The ROM BIOS baa separate alpha and numeric tables.
!"
Thj..<t ex.,mple combines the aJpha and nu.merir. t11.bles. */

atatic unaip;ned char keyboanl[O;i:70J [9] '"
{
/ .+ tWRMi\L

! A/N ;;/
J\LT
I CONTROL
SHIFT
Oxff. Oxff. Oxff, Oxff. Oxff, Oxff. Oxff, Oxff, Oxff.
Oxtb, OxOI. Oxff. Oxff, Oxlb, OxDl, Ox1b, OxOl, OxOO.
Ox31, Ox02. OxOO Ox7B, Oxff, Oxff, Ox2t. Ox02, OxOO.
0:-32. (h03. OxOO, Ox19. (;xOO, 0.r03·, Ox40, Ox03, OxOO,
Ox3J, Ox04. OxOO, Ox7a, Oxff. Oxfi, Ox~3. Ox04, OxOO,
Ox34,
(h:35,
Ox36,
Ox:H ,
Ox SB,
Ox'.19.

OxOf..
Ox06,
Ox07,
Ox08 .
0x(i9,
OxOa,

C::OO,
O:rOO,
OxOO,
OxOO,
OxOO,
O.xOO

Ox7b,
Ox7c,
Ox7d,
0;: 7 <:,
O:<.'r:f.
Ox80.

0l".f:f.
Oxtf,
(nl ",
0d f .
O:<f f,
<hff,

Ox ff,
Ox ff.
Ox07,
OxH ,
Ox ff .
Oxff,

Ox30 \ OxOb, OxOO, Ox81, Q:,rff _ 0;-cff
Ox2d,

OxOt~,

OxOO,

Ox82~

0A1f,

Ox 24, OY.05, 0:·:00,
Ox25, Ox06, OxOO.
OxS~. Ox07, OxOO,
0:,,26. Ox08 , O:zOO.
0>"2a, Qx09, 0;:00,
lh2S, OxOa, OxOO.
Ox29, OxOb. O::d'JO

OxO{:! Cb:_Sf,

OxOc, OxOOi

Ox3<l, <hOd OxflO, Ox!l.1. Oxf .f . O:df, Ox2b, 0<.(>d. OxOO,
Oxf~6 ,_ O:.:.Oe t \}'Xff, O~Jf. o.x7 f, OxOe
OxOS OxO~ . OxOO,
1

Ox09, OxOt, Oxff, Oxff, Oxff. Ox:ff, OxOO.

O~Of.

OxOO,

(h'rJ, Oxi.O, OxOO, Ox10, OxJ1, Ox10, O:d:iL OxjO, S_CAPS,
Oz71, OxU. OxOO. 0".11. Ox17. 0711, Ox57, OY.11
S_GAPS,

_lw.: 01,,.ric-r:run '"-/
/;t ESC i./

/ ,. 3 ,-/
, ••

£j

l~;

5 :.:..:/

.,/

/ :f

1,-.:/

/• 7 ··/
/·;-· 9 + /
'J ..· i
!.,

/~'-

/* TAB >.i
" Q ~/
/ ;,:

'!..-!

;:,/

0K65

Oxl?, 0~00 Ox1?) OxOb, Ox.1~. Ox45~ Oxl2. S_CAPS,
0~72, OxlJ, OxOO, Oxl3, Oxl2, Oxl3. Ox62, Ox13. S_CAPB
Ox74. Oxt4. OxOO. Ox.14, 0:11·~. 01.H, Od54. Oxl4, S_CAP8,

/ ": E t /
/~ R '~-/
-':-::: i ; j

lh'/9, Ox15. OxOO, Ox1fi, Ox19. Ox!&, (l:dil.J. Ox1f» S CAPS,
<Jx'lfi, Oxt6 O;:O(i, Ox.HS, Oxlb, O:d5, Ox5f>, Od.6. S.CAPS,
Ox69f O:d"l., 0~;~00, Ox17. Ox,t)9 (h~17, th:49, O>~l'f, B__ CAPS,

/:'· y */
/:t u
/"-.,(·/

0~6f,

/-+ 0 ..;../
/,,. r , 1

Ox18

Ox4f, Oxl8.

S._rAPS~

Ox70, Ox19, Ox00 1 Ox19. Ox!O,

Oxt8~

f) .._;9

OxEO

O:-d9.

S_,.CAPS~

O;::f!', fLrff f CJT_tt"

0.xl~~~

0~"..,7b.

0:·~1a

(LtOC'.

-OxGh, Oxl.u

0700,

0~18=

OxOf

Ox5d, Oxlh, Oxfl. Oxff, Oxld,
OxOd, 01lc, Oxff. Oxff. OxOa,
Oxff. Oxff, Oxff, Oxff, Oxff,
Ox61 OxJ~ OxOO. 0Y1e, Oz01,

Oxlb,
Oxlc,
Oxff,
Oxle
1

/:t· J
/" R.ET

Ox7d, Oxlb. OxOO,
OxOd, Oxlc, OxOO,
Oxff. Oxff, OxOO,
Ox41_, o~tf 1 S .CAf S,

, C'TRL

/:!. A ;1,

(b:73, Ocd£, OxOO, O«lf. (h:l3, O:df, Ox5:-l. O:dJ. S CAPS,
Ox64, 0.{2!J ~ 0~\.00 ~ ~.Jx20, O::d)~. 0!:.20, O-.ui-4, Ox.20 ~ S _CAPS·)
Oxl16 Ox21. Ox.00, OA'l.1, Ox0€. Ox21
0.:-:46, Ox2i , B .GAPS,
Ox67,

0;;.'.~2.

CxOO

(h:22,

OxO'f, O:r.:22, Ox·'17

Ox22,

i ,. n ~/
/

(h-:26i (h:OO, Oic2fi,

Ox,(~1_:,

O.x-26. Ox.4c,

t)x2~3.

J .t:/
/·;· E >!•/
/ :.c·

S_.CAPS,

O~Jb,

Ox27, Oxif. Oxf[, Oxff, Oxff, Ox3a, Ox27 OxOO,
Ox27. Ox28~ Oxff O~!f. Ozft~ O~ff, Ox22, Ox2B, Ox00

Ox60. 0:.:29, O;•:ff

/ie

'.t/

/-fr.

Oxff. O;df, Oxf'f. Qy_'fe, Ox::?.9. (hOO,

Oxff. Oxff, Oxff. Oxfl, Oxff. Oxff, Oxff Oxff, OxOO,
OxSc, Ox2b, Oxft, O~ff, Oxlc. Ox2b Ox7c, Ox2b. 0~00,
Cx7a_ O~~,-, OxOO. Ox2c. Oxta. 0~2c, Ox5e. Ox2~, S_CAPS.
0:::_7?3

F ,,./

/1' G ;·/

S_,CAPS

Ox6H. Ox23. OxOO Ox23. OxOB. Ox23, Ox48, Ox23. S GAPS,
0~6a, Ox24, OxOO, Ox24, OxOa, Ux24, Ox4a. Ox24, S_CAPB,
OxfJb, Ox25 0!'00, Oc2f,. o,,()h. 0:<2fi, lh4b, 0>:25, S_CAPS,
Ox6c

Ox2d, fh.00, Ox2d, Ox18,

Ox~~d,

;

·-:

(h:6~;

0}~31

!'°}y-f'-~
··~,.;,.

Gx19. {h:.20;

(:}'~_30,

O;.Od. Ox32, Ox4d, Ox32,
Ox33.
O~f f
O'df, IL:.ff, Ox3e, Ox34,
Oxff, Oxff, O•Jf Ox~5.
Oxff Oxff. Oxff, Oxff,
O/OOj Ox72! Oxff. Oxff.
Oxff. Oxff. Oxif, Oxff,
(h-:20, 0):.Jn.

0:~20,

(i_,.;}9.

S_CAPS

~·

It- M ·1~/

>t /

PRTSC

/ ;)<'

OxOO,
h

OxOO~

OxOO.
OxOO,

i•' A!.T -\/

/>1 Spa(.(~ Hai:~
/-# Cf.A.PS Locf.;

Ch::5a. OxOO, Oxbe.

0~:00

0_~5~1 1

0~·~00,

/•< Fi <·

O_-~~oo,

01J)f,

~')~·:00.

O;~G&.

OxOO.

/ .-;: F'/,

O,:t:fj0. OxOO, Ox55,

0:-:,00.

CxOO

Ox58. Ox00

0~3t.

O~OOi

Ox6~!

Oxon _ O·:\.·~-Q:
OxOG, Gx<~ 1,
c~~-oo _ o-x t2 ~
(J~{oG. G:cl3
Oyfl(i, o-.v:L4,

0~•-00.

(;J.:0(?,
()y;OO,
OxO:J,
O:dJ('.

Ox5d. OxOO, 0~-;:(s2 0):00. 1Jx59, 0_.-.::00,
Oxfie {1,,:(tO. Ox64 OxOO _ O-dia, 0;:00 ~
Ch:fif; oxne o::-65: o::,::uo. eixr~b ~ <:t~fJO.
Cx 70, 0:~,00. 0:-:r.66 < Ox(}G 1 (lxbc, Q_,.:_oo.
Ox'7i__ n.~'..00, Ox671 Oxor~. ('i_::fid. OxOC.

/>!--

}~~:.!

"'"/

/i- Fh :·-/

/:.o.: f6 :t/

Oxfi,
0xtf

0~_j'f,
~~--~

O~f!,

Gxff
Qyff

0.,".-c~~},

::~J-:4 ';.

(;_crf.]'f,

{h~GO,

~~~~

:-l-~ /

F3 *i

0}__ 51, OxOO, O:dJ7, OY.00,

Ox00. Ox62

B rf

t}:·~{~O-

Cx6? OxOO
Ox0-0 _ 0::-<!·'1, O-~~oo. Gx6ti 1 ~,Y(it:
DJ·Oo. 0".:2¥-~ C1:r.GO_ OxSb: Ox0(}

0~00,

/"'; N ~l

OxOQ.
OxOO,

Oxff, Oxfi, Oxif. Oxff. Oxif, Oxff, Oxff, Oxff. 0)00,
01::00 _ Cx31J,
Ox(}(i: fh.~~·c.

;o;

/:~:

0;~30,

0:.:42. Ox30, S_CAPtl.
CxOO, Ox;jl, OxOe, O:x:3:t, OX4i:L, 0J(3t, B.GAPS,

Ox6d: Ox32j OxOO. 0~32,
_,
Ox2~. Dx33, Oxff, ,,
():~.f i
Ox2e. Ox34~
ox:-J.:t.
Ox2f Q_~·3S,
f};.:.ff - Oxff, Oxff. Oxff,
0~2a
Ox37. Cxff Oxf·fj
Oxff. Oxtf. Oxfi Ox[f,
Or:20.

flx30, Ox02..

/* x ,,.,r

Oz.:58, Cx2d; S_GAPS,
1

0~00,

/1· 7 •</

Ox63, Ox2e. 0~00_ Ox2e. Ox03, Ox2e. Ox43 Ox2e, S_CAPS
Ox76, Ox2£, OxOO_ Ox2f Ox16, Ox2f Ox56, Ox2f. S CAPS.
OxS!!, Ox..'lO

_.:.~

FlD

t>-_;

Oxfi. Oxti, O~ft~ !)Xff, 0~00 1
G~GD, OzOO, nxff, O~ffi Ox00.
GxD(!

fr;-7'7.

O' 3't,

Ox·i 7 ~ S_ .HHM,

! '.i'.'

k~:,rpn.::1

{

H :c'. I
/-t= kt"._•,;pad 9
i _,__

k~ ,YTHld

Ox2d, Ox4a, Oxff, O:df, O:df,
OxOO, Ox·1b, Ox04, OxOO, OxOO,
Oxff, O;df, Ox05, OxOO, Oxff,
Ox.CO, Ox4d, Ox06, OxOO, OxOO.
Ox2b, Ox4e, Oxff,
0:-:00, Ox.:lf, Ox01,
OxOO, O:{fiO, Ox02.
OxOO, Ox51. OxO:l,
0;-.00' Ox52, OxOO,

OxOO, 0-:53. Oxff,
OxOO, Ox98, Oxff,
0>:00, Ox85, Oxf:f,
0?:00' Odl6, Oxfi,
OxOO, Ox87, Oxff.
OxOO, Ox88, Ox ff,
OxOO, Ox89, O:<ff,
OxOO, Ox8a, Oxf.f,
07'.00, o,:8b, Oxff,
OxOO, Ox8c., Oxff,
O.xOO, OxBd, Oxff,
0«00, 0>:8<>., O:df,

OxOO,
OxOO,
OxOO,
OxOO,
OxOO,

OxOO,
OxOO,
OxOO,
0;.;00,

O.xOO,
o,:Od,
};

Oxff, Ox2d, Ox4a, OxOO,
Ox73, Ox34, 0:<4b, S_NUM,
Ox:ff, Ox35, Ox4c, S.,NUM,

Ox74, Ox36, Ox4d, S_NUM,
0'%.ff, Ox:f f. O:df, Ox2b, Ox4e, OxOO,
OxOO, OxOO, OxiS, Ox31, Ox4f, S_NUM.
OxOO, O:df, Oxff, Ox32, Ox50, S_NUM,
OxOO, OxOO, 0776, Ox33, Ox5l, S_NUM,
OxOO, 01.H, Oxff, Ox30, Oxb2. S... NUM,
Odf, Ox.ff, OxH, Ox2e, OxS3, S.JlUM,
OxH, OxOO, OxbO, OxOO. Oxa4 OxOO,
O:df, Oxff, Oxff, Oxff, Odf, OxOO,
Oxff, OxOO, Oxc3, Ox.ff, Oxff, OxOO,
Oxff, OxOO, Oxcl, Od:f, Oxff, (hOO,
Odf. Oxff, Oxtf, Oxff, Oxff, OxOO,
0.xff. OxOO, Oxc4,, Oxff, Oxff. Ox.00,
Oxff, OxOO, Oxc2, O:df, Ox ff OxOO,
Oxff, Oxff, Oxff, Oxff, Oxff, OxOO,
Oxff. OxOO, Oxbf, Oxff, Oxff, OxOO.
Oxff, OxOO. OxcO, Oxff, Oxff. OxOO,
O>:ff, OxEf. Oxff, Oxff, Oxff, OxOO,

Ox8f, OxOO, Oxb3, OxOO, Oxa7, OxOO,
Oxb4, OxOO, Oxa8, OxOO,
Ox9l, 0.-00, OxbS, OxOO, Oxa9, OxOO,
0:<92, OJ:OO, O.xb6, OxOO, Oxaa, OxOO,
Ox93, OxOO, Oxb7, OxOO, Oxab, OxOO,
Ox94, OxOO, Oxb8, OxOO, Oxac, OxOO,
Oc•.95. OxOO, Oxb9, 01'.00. Oxad, OxOO,
Ox9£, OxOO, Oxba, Oi:OO, o~ae, OxOO.
Ox97. OxOO, Oxbb, OxOO, Oxaf, OxOO.
Oxbd, OxOO, Oxbd. OxOO. Oxbd, OxOO.
Ox9a. OxOO, Oxbe, 0:<00, Oxb2, OY.00'
Ox90, O.xOO,

Ox9b, OxOO,
OxOO,
Ox9d, OxOO,
Ox9e, 0>:00,
Ox9f, OxOO,
OxaO, OxOO,
Oxal, OxOO,
Oxa2, OxOO,
Oxa3, OxOO.
Oxbd, OxOO
Oxa6, OxOO,

/* keypad
*/
/* keypad 4 */
1-~ ke,vpad 5 ""'/
/* keypad 6 */
/+ keypad 1· ,. I
/" keypa.d 1 '"I
/* keypad 2 *-/
/« keypad 3 *l
/•'< keypad 0 *I
•I
I* k<l'ypad

/t F20 *l
/:;,: FIND */
1~ INSERT •I
/:t REMOVE .,;:/
/* SELECT •/
/* PR.EV */

/;, NEXT */
ur */
I• LT ''/
/ ·e RT i/
/ot DN #"/
I;. FU */
/+- F12 r/
/* F13 '''/

r·

Q,v;9c ~

l:;,:
'

f14 */

/"' F16 "/
/* F16 *f
fl?" •·/

/* F18 -:.,/
i·" f19 ~: /

I '~
-.-

COMPOSE :~; /

/:t: ENTER ~/

{
!'~!'f1rl) ;

~hiLe((inpCCOMMA~D)

b 0~02))

l~ write connru::n.d byte :',!/
/ r- w~.it u::rti 1 KC b.1u3 :t-e-3d •"!t:n:trr:to-.vl

/ o:~

if TRUE, set. paue 'Lhrcugh
e]e~ c.!.e"r pn~s hh2·ough

UtA:3if;U~d

.:-hFot· <:-;

1.:t:.sig.t.~.~d

int

~ntr __ ~lag

/·i, t~p tv:) hold i:o.teT:tFil

= int_off{):

;, ;_';:'" _ . :~:::_: <: ZHD Ch) :

c &."""· --Cx.40:
n~,:.:1G;

hyt,e -t/

turn interrupts off

Me cur~ent

gi~e

itip{~_;r,_J'f'tREC).

.if { :f ·:.~_g)
e .l ;;{:f::' c

r:.:ornm.~nd

tmp to hold CPU IF o~ate *I

:i.r1~-1 ... ftPig;

c~mman<l byt~

r~~rt :·omma.nd. byte f1~c~ dat-i& buff~r
if TRtJE. dri not decode k<E:'~{bgard i:t'a:tt~r~isFil~n)a
e- lSf). desnd"l keyb~Jard t" r.a.ne:rtd.tt.~i-o.ns
t~ .ll :.1Jter+ ace :_:t"'lnt:rn1 J f!"( t.tJ ~'fit~ :.:::u·rgv1nd hyte
/;., filP'.f3.d LOm•nar:cl byte tc v1rite
/-i- ~lln'-.1 it1ti:"':zr-upts

::/

.c.r./
"' /
•":
-:,;'

}

i.'.'.y[> _ir1 -,:. -~. ()

-r
/

'i.nJt_tb(&~:i_~rb

J.:.J~ey ...

establJ.$b rjng buff are

~;·

hut:f::oJ tn.1, KB~SlZ, JO, 1S);

i.r:..i.t ... r-b(&l-~~ .. rb. ~!f;ey_buff[t! [tJj, r. R ... SJl, 30, 15};
;_ni.ft;{~·::(t";,:J ,O).
d.J.~v:1bl~ PIG "l:np',}t; tor k•.:-~rbo~-_::.-1 :tl:t.t:e.r·f~c~ ;"'/
/~ k:eyt;~;~rd :.nt~r.t"',J,pt ifi int- (}Y,<)9
en~blf'.· PJC i!:pu.t. tzn.~ 1--:f•yb~Hi·cd ~ri_tr"Tfac~ i: l

/o::- ·,~r_kyh()

- !;'1Ut

~nilue i.11

ontput buffer to -keyboard and At.art rlr!:lfld

,'<(/

/~****~~~~*~~~~**~$~~*~~~A:~-~*~*~~**~~~*~*~f•~~~*4~***~4••~****·~~*~·~·~~J

value to aend to keyboard *I

{

un!lign<-d int;r_flag,

irJtr_flag ~int.
rb_in(ika_~b.

of 4 ~).

~alue),

if(llast_aend) kyb_aend(O).
int __ on.{intr_ilagJ;

CPU interrupt~ qff •)

/•« put value in riug buffer ··/

if keyboard not wetting far ACK w/
!+ Bllow interrupts new ~!

}

kyb~led()

{
11:1sig1~ed ~har

~t~te;

v tn :,e &~ Ox.C7 ~
v;r _kyb(LF.0123).
wt" ...J-:yb(i:.:i-tatc) .:

/~·

temporary state vaTiable Y/

!• shift lnta paaitton ~;
only· bita 2:0 are valid ~1
•• keyboard LED eommand to buffer •/
LED o::tate to buH<er- 4
;~.

{

if(rciH"nd.) 4:iutp(DAt/1JlfG. laBt.~nend) ~
ze send cummund nr da.ta
if(rb_out(&ko_1b. &la~t_nendl >= Ol/~ get char from output buff
G•Jtp(UATARE:fJ, la!'lt .rrnnd);
i' send <:omlf.end ·:n: data
else laa~_aend ~ O:
!• nu chnrnctex ta r.end
#

~lee

}

8·· 54

Keyl:manl·!nterfan: Controller · Programming l.'~xampie

""-!/
1-/
+/
*I

l<'.'h restO
{
i ''~rest (Ox09)

/" keyboard interrupt is int Ox09 ,</

}

!• get_kay(} - get character from keyboard input buffer

int g<it __ key(pc)

/» get char front input buf ,,/

unsigned char

!• where to put character •1

~pc;

{

Teturn(rb_out(kki. :rb, pd);

/''' get char from inpnt buff

/" pnt,__ keyO - put key sequen<:e into keyb11ard input buffer

J.nt put_key(pc)

;"+ put key seq into input buf '"/

I• where to get sequence ~;

uns i.gned char '' p<:. ;
{

iHpc[O]

Or.ff && pc [1]

Ox ff) bet'p 0 ;

/• invalid kev combo

•/

els.;
{

rb_in(dtki rb, •pc++);
return(rb_it:i(&ki,,rb, ''pc)):

/• write ARCII char~cter •/
1~ write acan ~ode •/

}

'J:

Keyhnard·lntnrface Coutrnl!er · Programming Example

~.ell

·~!;.i :i "Sch(--;--~]. C~t;t;;d

key

!sle~s0

~a~~

{

1;yp1.et tuf fer ~;11.1
or ~~ybc:a2J r~p.l~ ?

fo~

d~~io

t~d. (:b~~k mcrlif~.~~·

:·~1~~~~d

k~y

~evu

}.e; r·e1.~~2~d
c1PET ~r~~
t~t~ byte

~c:1~r~

riF'..h.-~~

;

s:.b:..Jt.
~l-~5~-

~:i:y

fr0m

t;;:;.1.€'G.ct:~d

Bt~te

·r ,,./
!

~y1;~

/* i.nA~rt key releaaed ,r *!
~vb

state&~

S_l~~:

1•

cl~a1·

ftum Ptate bvte

h1,!:ak;

/·-"-'. ni:) default

el.se
{

·ca>n• CTRL
.J:Yb _ "'tai.c

~ont1-ol

key pr~esed ? */

/* :a.et in ata.tP' by,te

S C'TltL;

it-/

b!'!'!lk;
,~ a~if!

l@ft shift key pr~es~d 7 *:
/' set in state byt<> ,

LSHF;

- . b BtaL.:>

/-·"' .t i.ght ~hj_ft ke.}~ pret;a~d ~t

CRaeRSH.f,

/• set in atata byte •/

K~,._~b-~ta t;t:

case ALT·

kyb_atate !r 9_A~r;

~ape

lock key pressed ? 11
/,.:,-; capP on ? 1!/

~y·b.state &~

else jyb __ Atate

-S CAPS;
[~

!* turn caps off *!
ath(';w.i.rse, turn cape on :.:· f
/Jr, "dj u~t Leck I.ED

S_<~APS;

k/b __ lP.il ();
tir~~aY~;

if{kfb_DtRte

Kyh .sta~~

else kvb_ otatQ

S.\UM}
S_NUM:
l~

·--o

nu.rnlock .key pressed ? :r /
!!. numlock on ? */

/'.'-<: torn :rrur:~l0.::;k •Yff ':c/
ntht::r\liiBt! r t;.u-n nur~lo-cl:, on ? -t/

R.. NlJ~;

~:yh_l«d ();
ln~ea};: -

1rc~.:yb"stat.t_'. k

s SCRi.1

1Lyh_9tatu k~
else kyh_~tatc

-s_sCRL~

!= S.~SCRJ.;

acrllock kev presae~ ?
;-~ ecrjlock on ?

/i turn scrlloct off w/
I

otht~T-wise.

t~1rn

scrllock on *!

lNS.

cas'2'

kyb_stat~

~11eert

key piessed ?

~ ~

f* eet j_n state byte ¥/

S INS;

bs·t~a k;

de~f au11;:

k~ya

alt k~y pr€ssed 7

teat for combinatioz1

J.f (kyb .. Bta ly

S ./.;LT)

il (kyb.~_state & S~ GTR.L)

ctr!

key prese•d ~

{

';'o.'."O'

/;! GTE.LIA.LT/DEL 7 -t-/

DEL} ;Jyfj~_rt:t:\t'd:();
!~NOTE:

elae be•p(];

Ai~/CTRL

table in demo.

}

'!'ltH: iI(kyb_at11te k

(S_LSHF ! SHBHF)) /" shLft J;ey pr•aried? >/

{

beep 0 ;
}

''
else i i

.'.!< /

{

state & (S LBHF

i B_RSHF))
/*

ahtf·t kev preRserl 7

NOTE; No GTR1./SH!F'r tabl.@ j_n demo

else put_key(kkeyboardfkevl l,l_CTRLJ):
}

elae tf(tvb_state & (S LSHF

shift key pressed ?

{

if(k~b.atate

& S_CAPS)

pl1!._key(&~eyboar·d[~ey

~1st.~

[l_.NORM))

tn11,_J.::-.ey(&:keyboardLkeyJ[T_HHFTJ);

!o~k jn_ effect ? ~;
use nor~al table ? +/

capo
!*

1 ~.

t.iae tlhi:f1, t~hl~ t/

Kcyhoard1nterface Controller · .Progranimlng Examµl.e

<'lliw if(keyboanHker) [T l\_t1] & S_NUM)

/·'· numeric charact,er

,./

{

if(kyb_sta.te & S_lH!M)
/~ numlock tn flffect, ?
pn1._key(,!freyboard[keyJ [T_NORMJ) ·
I• use normal table
eln·~ put_key(&:keyb01u:d[key]
SHFT]):
/'' UIH' shifi; table

n ..

1•/
*/

}

else put_key(tkeyboard[key][T_SHFTJ);

use shift tabl.e

}

elao put_key(&:keyboardfkeyJ[T_NORM]l;
br0ak:
}
f;Oi (0) ;

/* end of interrupt to PIC R/

Toggle OIG!TAJ_ e~tBnded mnde an or aff~ 1
Sc~

:f4,

>•'f';j.

{
1

k~y

volume· 1 } ,
To~g~e autorepeat o~ or uff' 1 ~:
Set ani3frY-epeut d".:1a~.r antl ,rett.e 11 ) ,

Sbo~ key~os1d v~~~ion

Rc·g Lcre i-::f:-ybos.:rJ ti:•

1.1'

1::;

2,-~

FiO
r~

cli~k

Shaw Inst

d~prcgoed

S,eti:::::;,

Mai:r1

ti:-1

.fr-~nn·

and mode', }

d~f at.t. l taH

and laat

} ,
releag~d krvH:~

·J.

,. .

J,
1~

>.,=;

int auto =ep i:::1t

to hoJd PXtendad ffiorje
1~ to hold nutc ·r~pea~

~~'.

-li,

1nt
'J n.t v
/''

,~•1 _}::-Jb t.AR.EPON; :

toggl~

stat@

tuggle state • '
i.np~JI,

':_,'

hold input
/fl:. to ttold iv_pu.t

~-/

/:::..

tn h_,:)·ld

tQ ~~n 1 Ld 'JPU If statn

~nsure

ig Qtl ~/

autorep~a~

* pxj.t e~tend@d m~de *i

wr~~yb(E.rr __ EX~!/) ·

f:~-

~inefc:]

/:t< n.uTl line :+./

~ 0,

l~d

~H!

.,--,:- .YC) b \LJ'Jl>L_ntl) ,

~..,;!1.~1~; ( j}
1_

av~i tch (]int~:;..,!":

d.inp·i~~l};;'

H":Pr.ru. fo::r kB-yb1.)£f.:rd
1~

~Yainp1i.~

·;-/

wl1ich fun~tion ~ej· 7 :~/

{

/t ·toggle e~tendcd ~~de /;
.:f (~xt, r'lnd.':")

Wt" __ ,cybiEXT .. EXNl,
',;1_1-~-,_·b\J.ET:,;

8- ()!)

•}[·:);

~xtended

~~it

mode ?

e~te~ded

/;~:

i~d

~ode

it4 i]n '1</

'°"J" _kyb

!~NT_.EXM)

•,n- _.l~yu LFJ).'.i _OF) ;
1,

/~-

r·fu3e F2:

chan~e

key,.-: lick ·:tolum•:;

''~/

GDL.

diep.str(KUH

11 The
J~ey clic1: velum~ haB a. reuge of 0 te 6
disp .. ntr(ROW
1: CJ[..
Of! 2
tJj gh'' j
disp_8tr(RUW • 7, GOI.

Jn~

incr·ement$•·)~

'(Fnt~r

k~-,·

·::<ti·::~:

get_ke;s(~flW i·

sar:anf Cl in~~,

-.!-nl.ut:;.(; {O - 6) - 1 ~):

/ ,~- get cb i cH:e ,i:.:
to int :1!

C{JL + 36. line);

I· ftecii

'/"d",
1 ~'

/-~

wr kyb(SE'IVffL.};

'#r::tt.~

tt in tH:ondn "" !

ke~p
ae~,

·.rolume

::_~nmrr:;l_1,nd

~:,,

wr __ k:yb(y)
br&-ar:. -

,·aee 1'3 ·

/1 toggle

.if (a,1tr«. r~p)

~1Jto--~epeat

au~o··repeat

? ~1

off

{
a!.ltorcpH<" t; Dt1

clear toggle

els~

{

.!-"" antrJr-epeat off '«/

w IC _k,ib{AREPOFF)
t\iltO _.r~p

/+ n<?t t.ogp;Je ·':

""'

case F4

set auto·-1-eµeat,

r~te

diap_str(ROY_ COL
• 1 --r.t~

uutorA:p~at

!'at~

han a xanp;e of 2 to 30 in 32

irJcr~.~ments 1 °J,

disp .. 8tr(!WW + 1., GDL.
0

lhc auto:£peat.

::~~.tt:

l£~

,;:11l<u!ated as fc} lcw£1: a;;

diAp.str(Hnw + ~. CUL.
"Rat:e

(. 0041'r ··

CrYJ _,

a)·· i;

disp ___ ~t~{R.OW + 3 COi.,
'•The delay, bntore auttirepAat begin~. l1as a range Gf~ 1 )

di£p __ atr(ROW + ~-. CQI.;
n

25' £€<"O!Hla i o J EHJC(:O-JJd Jn . 2-S eecon.d. inr: !e,'":lentg 1: ) 1

Keyboard·lnwrfote Cnntn.il!cf· · Progrmnndng Exomple

11 Th~

delayr before autorepeat begins) is calc11lated as follows!''):

di:sp_at;t~(ROU

+ 6
COL, url.elay ~- (P ~ !)
diep __ str(RDW ~ 7, COL,
t?:Ent0r :r·epecnt ~fate Y '{alu~ (f)
3}; ");

,11'

25H);

dtRp_atr(ROU i· 3. COLi
'.t:nter J:f.~peat ra.t~ X. V<'i.lue (0

d1sp_str{ROW + Q

if<~·

··-=

t!QL

i I y -,. ~1) 't ~ 2;
R CO[. i 36: Jjue);

1~ k~PP

in hounds ~1
/·'' get input. ,/
1~ aacii to int */
;~ keep j_n b,1unde +/

g~t_ieys(ROW ~

!;H~cs_11f {lint:: ll%,dn
-t f (y. < 0 ~ ! -~· :"- ~~ j

&?<:):
:~

= 2;

get_~eys(ROW

COL·~

~sca1;.f (line,

·=~,~d" ,

~d} ;

30( line):

/.:,- get input x/
t.;r; int -4' /
ke~p in houudA +;
&!J"-':t.i

itld < n I I d > 1) d n 2.

~h1.ft.

intc corre~t position ~;
nbift into coxrect pnaition ?/

/4 write set Btlta~repeat rate command~;

/:+

int:r: __ fl~.g

ir;l:-,_~>f-f()

pass_t.h:tu(If£UE);

-~1rit?<

/;~

au_t(~~ :rPp~.a.t

CPU

int1'~<.t:rupta

dat;a -f:./

off -r_.

/:lf inteiface contr0ller in pttf\a-tbrough mndf" ·" ·

wr_k:.:.d (KY.BID)~

i'<lid.1 ~ ( : ( lt1p ( CG~·1MArHJ) &. Gx01))

k W«ri t,~ l-::eyba~.rd lD command -:av~il.)j_bllff ;;;/

/* waJ.t 11ntil d~ta

/'1" :ce~.d ~re1.-fJ:io:!! byts i'/
wait until data available '!
1

I~ rearl

j_np(DATAREG};

p:a:ss_ttrrH(P-~4.LSE),

int __ <~n("irl ~-~l

i ( :;.~

'"7:'"-\

int~rface

mod~ byt~

/* n1·c1TAL ~~tended ~od~ ~

i'~eyboard vcr~iun

c0trtr-0J J.er :Lnt:e.rpr~-t~ ,,, .-'
/·A CPU i!d.~:r.rtrptu ,Jn i-/
~:

n%d is in DIGITAL ex~ended ~ode %d 1' , y. x):

'·Keyboard vc1A~on #%die j_n industry-standard mode %d 1' : y.

~);

d.i.r.F- 8t1. (F.C.\-J,

<:a!~e

FE·

v;T _kyb(RESDF:P);

/* reset k6yboard to default values ?
/* w1.i.te .rerH't to defa\llt u:imma.n.d

Controller · Ptngrammlng .Ex.amp!<>

caae F7:
J~ ahow laat praaaed and Jaat released keys ? •!
l ine[O]
/* nu.Ll line -:·/
di sp __ i;tr_ (fWW, 0, 11 Prc~e F7 agai11 to cuncel
11 ) .

while(Une[OJ

0 11 line [LJ

•~· Fl)

/• F7 terminates ·/

{

sprintf(line, "Lant depressed: %D2x", depresaed),
djsp_atr(RUW + 3, 0, Jine),
gprintf(line,

1.aa:t

:released

'~02)·_!•,

releaf;etl);

disp_etr(ROW + 3, 40, line):
chk_dt(),

display date and ·tim.e 1

if(get_key(&line[O])) /• ecan code •/
wbl.le('Ret kev(&l!nefll)l /s character code 8/

Cl:l.se

F!O:

return;
}
1~

get menu

aelec~i.on

}
}

Keyboard· Interfrtce Cont.roller - Programming Exmnpl•:

Chapter 9
Serial Con1m11nications

·":·ron.-! t~n.: int~~'.1-r-.1.~: bu~·;c:~~ i:.3 .:;.:edDl {i;:;.~.;J
f(n· tr~u:&n1.lt;s{·:n: :.~_,, {::_'.":.tt.:rn.~::I ~_i("~,,,1ct~~!, 'rh~:: H2GfJi\ Uc:\I-rr ((~·:--E,i~J<;~' s~:!r:.!-~l Gat~_; ;n1d

~l\1L~ ~·~2{:~if/\. ~_.:'./1.HT ("-.ur:\'"'<Tt::;.; p~rr~~:h:i dat~-t

,-\dditio11al

of InftH~Ulatio11

1)--

8250A lJ ART R.egist<~rs

Cmul

Mo1fom
~C·on12!

02f8H

OCAOH

O:iFHH

02F9H

OCAlH

Interrupt identifionion

O:ffAH

f.l2FAH

DC1\2H

Linf:; cn.ntrol

o:.iFBH

02Fl3H

\lCA::lH

Modem control

U3FCH

02FCH

OCA4H

O:SfflH

O::'FDH

OCAiJH

IV! odern Si,atns

oaFEH

02FFH

OC.AGr.l

Receive buffer iReodl/Trnnsmit
holrlintt
i\.i\-''ritf:~~ or
Divisn; intch \LSB) ~
In~-errupt eunb~e

or Divisor latch il\ISB! •

Bit i of the iine control n•gister controls access to the divisor latdu's
The lirn:; c.on1;rol
is described later in t.hl\ chopter.

Receive Buffer Register/Transmitter Holding Register
(03F8H/02F8H/OCAOH)
7

DATA BJTS

Bit

R!\V Description

7·0

Heading this register ai-ce.sscs the receive buffer.

Writing I.his register <\('Cesses the tnmsmittcr holding register.

Bit O H.he Je;ist: significant hit) Is the fir·>t bit tn1nsmitt<·d. or
received.
··
\Vhcn the line control ..,,,gister is p.rogrammBd for word lengths o[
!ess th:rn x bits. the unu«ed hits arc re3d as z.1•ros.
\!Vhen bit 7 ot the line control register is set to L reading or writing this registn accesses t.he least significant byte of the divisor
latdi.

Serial Commnnkutioas - Hnrdwarc Description

9 - ;:i

{()3F9H,{i2F'9H:OCALH}

:v!(}C~'Efvl ~:~iTJ\,'.CT1S lNirr~;)"T'

r~tod~~=-~i": StKtdS

!\ ~:6tn:·-~ ~.~~,;)tdS

d11'''!;led

1\i;' f·tl er.·:·1 :~;tz:~ t.t.1.:-:~

iin~,: :.~t.:it;..~~

1 .'.~~:

f·~CC{'i·",Je h~·1e i~t~~f.as

dL-;abied
~

..~. _ t. ~· '-

\Htt:: ;.nr.~;~'r'··t.'.pt, (;utp~J::_

IirH:-, .'/f.•u ~J):.~~.t. ;·<:,·,~({

~-·-~t~t:e;·•!-iiL::~ v~hk:h fi,,.u;cti~-~n C~( L1r1(iff1.~~:.::,

is dc:..;crihed later hi this chapter.
f<; us0 the 82GOA UART in an interrupt·drlven environment vou
mast prngrnni llw peripheral interrupt 1:ontroller. For more in·
formation nn the peripheral inJerrnpt controller, st·H
:3..

Sm·iul Cnmnmnicadnns · Hai·dware

Interrupt Identification Register (03FAH/02FAH!OCA2H)
6

INTERRUPT JDENT!FfC1\TION
Ttw;;e two bits id1.mrih: tlw higlwst priority
fable 9<' rhdincs the
of the
H

fNTHPT .PENDING lntcrrnpt
One er more !nrcrrupts pending

O =

l ""'

No interrupts pending·

Inte.nupt
lD Hits

tlighcst

I1ttP!'rHJ:lt

Intenupt.

Enah!e
Regi;;,ter
Bit

R>"set

Heceivcr line

Overnrn, parity
errrn-t

t.i1~~ ri::~~ ..

RP.-reive. d.tltu
iJ'V.ii Uabl(~

t.·-eiYe hu1fer

hutf(..,r
T'hird

1'r.ansn:£.i1:, hu~d~
ing

~rt~lnA1niL

hnh:i-

Uit'
n1odern sL.tL1s
f(;_tfiktf~i

Line Control Register (03PBH/02PBH/OCA3H)
7

VORD LENGTH

n;w

RIW

Descriptinn
DLAH · Divisor hitch ;iccf\SS bit.

0 .,,,..
1 •oc.

Ar·cess to t.he divisor Int.ch is disabled
Access to the divisor latch is enabled

\Vhen ar:cess to the divisor latch is emibl.ed. the least signifinmt
byte of the didsor latch is mad or written through the receive
buffer/transmit holding register, irnd the most significant byte of
the divisor latch is read or writ:t<'m through the interrupt emibl.;;

The divisor Intch is describt~d later in this chapter.
l'
.}

H/W

Rf\\.'

BHEAK ('( >NTROL
0 cc-.: Bn;ak disabled
1. ·.cc
A span.:
fl) shite forced un t.h<:'. serfr;l output
ST!Cl\ P/\HXfY
(i ~

l =

Stick parity disabled
H p:.n·ity is enabled (bit a eqnalf• l L stick parity is enabled

'.Vlwn st.kk parity is enabled,, the
recei\ed in the foilowing manner:
•

•

bit is trnnsmitted antl

If bit 4 equol<; 1. thP narit\' hit is alwm;s transmiU;ed and
rcc<'ivcd i•s a 0.
'
,
"

lf bit 4 ·~quals 0, the parity hit is always transmitted and
'.'f•r:eived flS n l .

IPN

P,-\IUT:t SELECT
O ,:::.:::

E~v-en

1 ::::::

()dd

!except for stick parity as described in bit r,:
h:xcept tor stick
m, described in. hii. f>1

Serini Commm1in1ti.ons

Hardw:1re Descrlptiou

Hit

H1\V

RJVi'

PARfT'i E~~,\HLL
0
dis1_:thled
P;Ltity flWbl.ed

fU'rV

STOP BITS
0
l stop bit
! ---1 /2
iJ! ts i fi-bit. vd;rd
(H. 71 or 8-hit

crbLs bit ;<;;cts the n1HTi.ber nf str;p bits only fo-r transrnitted
ch:~r(1cters. 'fhe r(:eei"..rer u:sc,5 urd.v the first stop blt detected.

BJ\.V

\VOHfi LENGTH
00
b daw t1its
OJ
n {fo\.t1 bit'.;
\);lf.~ bits
! (l
l l
8 data bits

Modem C'.ontrol Register (03FCH<'02FCHiOCA4H)
7

1-15

WOP

o __

J o_

Bit

.RIW

Desedptlon

f.-G

Hf\\/

/\.lwny~

HJ 'lV

mrr2

OU'I'l

RTS

OTR

- -- ..)__

L.f){) P
I)=

loopbAck dis0hled
looplmck enabled lse1~ the discw:;sion that followsi

l '"'

HJ\\' 0l'T2
0
The buff<cr between the 8 zr;OA U AR'I' internult out.pat <Hld
the peripheral intc:rrnpt control.let input is dh;ablect
"" The buffer betwerm tlw Fi250A UART intHrupt outptit ll.nd
1 he
cont.roHer input is cnablt;d.
E>1wh 82!'.:•0i\
butler between the interrupt. output Ene
and the periµhcral interrnpL controller input. This buffer is con·
trnl!crl bv bit 3
the buffor enable.; tho 8250A U:\HT intf;rrupt t~utpnt line,

To use i:he 82;)0A U;\HT in ;w interrupt.·<ldvcn Pnvir<Jmne11t you
mrn<t prugrnrn the peripheral interrupt controHer. Fnr morn inforrnntinn on t.be peripheral int.c1rnpt o.>ntrol.ler. see Chapter :L
Ri\-V fJCT

!not connef'tt•d to anything)

R:W HTS · Hci.:nrnst to send
0 ·•"'
l "'
n

HiVV

HTS is a imtic 0 at ihe extNnaI conrn;<:mr
RT~ is a iogic l nt 1.h<} ext~rnai eonnednr

rrrn - i)nt:rJ tertninnl readv
0
~,

DTR i;; a
DTR b a

0 at t,he external connect<;r
at the external connect.or

NOTP:
~ee the ~ection -: ~jJoderrt Contro~ l'rc,granuningthi.'>

Serial Cmnmunii·ationB · Hurdwure DescriptiQn

!:}

DiAgnostic Loopback
\·Vh<m the diagnostic iooptmck ls enabled. the folkiwing conditions <'xist:
The serial ontput at the e:dr'nwJ comiectnr l.s !•et t.n a spaf'e

stete.
..

The serial input is mternally discnnnecrcd.
The ou1,put of the trnnsrnlt shift
input of the n.-~eeivt;r shHt.

The four modem

is int.crni1Hy corni.ectcd fA, the

iIJSR CTS. RL and HLSDi an' inr.ernn!!y

disconnected. The
modern
are -connected to thn four rn.udern

(D'flt HTS. OUTL and OUT~!)
ns toiIO'IVS'.

The DTH m1Lput is connected w DSH input
The fl.TS nmput ls crnmen.ed to the CTS
The OUTl output i;; •:ormPCtcd tr> th<''
The OUT2 output i.s ::onnerted tn the
~vVhen

luopfJJ<~k

iE. enabled, thr:· re1'eivc ;-;nd transntd.
l~hc tuodern .t::nntroi a.r:d the Hne status inter·
rupts arc nlsn funclioniiL hut th•' snun.:e o! the
i1'
as fo!!ows;
thP

ctn1t.intH:: tn furu:tlon

'rhe line .st.nh1s interrupt is fiFth:2ted
Yrri_ting (.1_11 appropriate=-~ \'a.lu1:::: tu
one of th•: fo1e stat.us bi.ts 5-0. A t>et bit c:Tate1> the
ecn1diUon.

Tl10 rnode1n st~1rur.: intr:rrupt l'-1 3ct-ivnr-.t~-d r)y

t,, one of the modern st;JLns ,...,,, ..."·'" bits :Hi
rnpt COHtfaioH.

Line Status Register to3FDH/02FDHiOCA5H)
.5

~;i~--~l!~~[.i~:G·if~~~~--1~~~~fNG·r~i:~f ~ i~~UNJ~!~~IVE
0

REG

EMPTY

-~-~-

Bil

R !\~i

-~~--~--~·

-~~-~-~

--------

Description

R
R

------~-

RF.ADY

()

Xl\'llT SHIFT REG i;;l\fPTY ·Transmit Shift Register Empty
Transmit shift registHr contains d!lta being transmitted

0 o:.l =

Transmit shift register is empty

This bit. ls cJ~'ared by writfog d;:ita to the tnrnsrnit hulrling
R

XMIT BOLDING REO EMJYfY Tramnnit. Holding Register
.Emptv
0 -· ·Transmit holding register is full .
l
The 8~50A U/\RT i.<> ready to accept a clrnrnctt·r f<H'
tnmsmission. lf the transmit holding reg-ister interrupt.
cnabk bit {interrupt enab](~ rcgisterl is set this condition
ernate<: an intt'nupt.

This bit is deaned by writing data to the rrnnsrnit holding
"1.

Ri\V BREAK lNTHPT · Break Interrupt
U
i ·c

Break interrupt is 110t <ictiv;!

Tbe serial input line a1 the connccto1 hns been held in •i
mark Hogir U state tor lrmger than a tull character
trm1smission, including shu~t and stop bits.

This bit is cleared by nwtling this re~•;ister \1r writing the bh.
3

H/\V

FHAlVIINO ERROR

n -"•=
l

·-c

No
error
The received cburacter did n<1t h;rve a stop bit.

This bit is deared hy reading this register or writing the bit

St;rfol Cummunkation$

Hardwnr,; Dcscriµtion

~---

'r>e C'.P1) (.ikt r>:;~_; n-;;JJ.: ::.h(" drtt;1 ~-·a Lhtt- i:lr_-:cco-;-/-:"" Buff,_;~_,
It~~ t.,ef~y-e tht:~ i~t·)!;t t~b_fH"°~H-~b~r v,;a~ rr~t_~.Hive•i. 'ri.:_ll5L

c'har.:1ct,~::t '/./i~.s

\·V~-H~c;

rdry nf ~-1~t.s 4~ l :an;: ~3t'.~~~- a .tf:'.ff;\-'t~.f· ~:~-..H~

\'\/be~·1. bit 0 ~·'i ;:;.c:_~t a ~-'fr~~eiv~:: r:-i,c:.~1 ~FY·a.i~a.bii:~ int(;J rupt J:i

the ~Jr;n}8rl

lVlodem Status Register (OaFEH/02FEH;OCABH)
,,
_,,.
,_"
(,
7
1
J
i

·· 1

RLSD

DSR

;:1

'.l

-T ---

;-"-

DELTA
RLSI)

--- ,_l

DS fl · Data set readv
U
l)SH: >Jt the exiernal •.·onmector ii' n

(:TS

Clenr to send

("I'S nt. thr: <-:>xtern~d rnnrH~t~tor i~ n
Cl·~s Ht the CXtf-J:TJ.Hl co:HH'.~Ct/ff _is (;i

flCLTA H!..':.:il) · Delta Hi•t(·ive I.inc

CTS

TH.AIL
EDG1' OF

H.LSLr na:~- not

THAJL ICDCH<; OF HI ;J

Th~:

indicn.t.nr ha5 1J_qt
h1_st t.irrie this
at the s~<.r.erna i co:·H1F:ctnr
Sintf~

this

rlears the hit.

DR LT A
DSR

DELTA l
.t ......,~,...
~_, ll..

,Ji

Bit

the
bit,

Sinee tL!c Inst tirne this
hi.1H changed stat.(:.
(-:!ears tbe hiL
R

DdUi CT~ - Udr.a Cka.- to S+:nd

0
1

(~'f~~

ha::-; not

~;tatc.

= Since :h~~ in.st tltr)f; t-h1s

n Hny of bits :"\-0 1n tbc rvlodt-)!11 Star,ns
rupf~

i'.'::

Blts 7~4 are the c{,;.rnph;xnent uf r.hf

J-lGv,evr:;r the ftS~:2:J2 !'£C.f1-i'Vt:r buffer i:rv~~rt-S theS.(-:'..

Divisor Latches
7

- · ---,---·-··---- ·-,----- -· · r------.r·----·-

,------·--·-r··--·--·--···-·1

DIVISOR LATCH
LEAST SIGNIFICANT BYTE

.1 _____ l ___ _ L______ __ L_ ______ J____

15
-

_.L._

!._ _____

--1--

DIVISOR LATCH
MOST SIGNIFICANT B'ITE
- --·-··_l

\Vhen h\t 7 ol the !inf' control n'gii,ter (Divlsot latch iF:cess bJi,) is equal to 1
the lei-tst significant byte ot the divisor l;.;i.ch is fl«!CI or written thningh the
recd'-'~' buffer/transmit
, and tbe most sig11ifiu.111t byw of the
divhor latch i.<J remJ ur written through the internipt Pnable register.
Th1:1>e two. 8-bit lnt.rhes store '' lil·btt divisor in the range to !36J1'.J:'i The
output t.:equency of the baud rat•• gent:rntor is l .84:\2 !'Vlhz divided by tht' l f,.
bit divisor. 'These did.•;or.<; n1ust be loaded during initialization. Tlw desired
omput

is u: times the d•~sire<l baud rate. TabJ,, ~l<) list<> t.hc (livisor

used for tlw standard bnud rnlc;.,. Table B-a was cnlcuhitPd
fnnnuln:
i.1843200

I. fi} / d(;-'S£tv<f

the following

~JU?f<.i ,-ti-tr__·

Sedul Communicntions - Hardwm·r· De;.;cdption

9- 15

P-:.:.::Y·.;;::::1t;--1g<:.~ ~Jf

f;; i.-1.'1t· f.\E::t-.,-Y~>:_'.- i IJe::h(:d

and i·\:'t:_nc H<il-<'

110

192

lVloden1 Control Progranuning Exceptions
Speed fiell'ed and Spt>erl .I ndicA.tur control sie;nals are not controlled by the

8260:\ U.AHT !.nst.ead. these sig·nal> are controlled

writing to a special pm"

POSE~

The :<pt;cial purpo:,,;c>
NOTE
\Vhen

the Speed Selen or
Baud ffole. maintain
the integrity of the other bits in this register. Split bDud raks
are m:hi(wPrl hy switching the output tHCLh. Bl bt!tween two
sourcr!s, BD OUT CU< (baud out of Uw 825(!!\ UAHTi and a
t 200 baud <:tnrnter.

Special Purpose Register (OC80li)
7

·-·-···1--·
I
.

jYRITE ITHACK 0 INIJEX
IPROTHCTI
-·

.m.t

SPLIT

DISABI.!\ SPf~RD

HMJD

COMM

SRLEGT

fl.,"W

\Vnte

diskette drive is not writ.<-: rm>tecter\
is Yvdtt,-5

0 -

I -

;;~:!lccted di~kf~tlt~ dsive

[{e:i,l fJJ S•i'lect!'d tfrcikette drive is not at track ()
IJead of sel~~;t~-tt:d d~~kette dri_\'t: is at tr.a.ck 0

t ~~:

J:f)f:(~X

n =--

index ho.le

f:ir ~der:Led diskc~te ctrivc

[ndex t1qrc in

.<><':lectr~d

-.JisketttJ d.d\:e

.,
ll

\--if:dern cuntrni Hpt,~<::d st.:-lert a~s~~rtc·n

1 : ;:;'._

f\.:i(H.it.rl:l 1;ontl'o! soeed -~?eJecr not asst~rt.ed

(; =

Virk<.• ''>Hrl" utbr dis11bied
Vfd'f:n (:{)rttroHet f'-;nabJed

EhnJd .H~1tt-s
lfttY:e.ivt~

1-1,tV·/

:,-::: 'frJns1nit

_[)i_:-.-;;;1b~..:; t:ct:irnur;_ic;~_t..~on\

O -: : :-

[.n~e:t::;·a.i -:~.urrn-~_-i:.ir)f.cat.ions porn:~ c.onn':_:(tcd. t.1') I/(J address

Communications Connector Signals
Tlw communications connector, r; 2G·pin. male. lkrnbminiature. is located on
tbe rear bc:rc\ of the VAXniatc workstation. Thi~ eormedor i5 functionall.:/
1:ompatibk· with HS-232·-C and electrically compatible with RS-42:~. configured
as DTE ( Dat;i Tennin;il Equipment). T:1ble !LI lists the
supporu:d by
this connector.
Ti1blc HA

Communiralfl:mo;; Cmmector Signals

Signal Nmne

Protective ground

·.

..
i

8
D
lll
t ;
''

Transmitted Data
Hei;eiverl l.Jcita
H.equest. tu Send

Clear tu Send
D;,it:.i Set H0adv
Signal grouml ··
H.eceive .Line

Detect

Not used
Speed Indkat•ir

'.!.J
~2

lndicatot

Seh,,_:r

S1::rlal Commimication,,; · Hardware 01'scription

H HI

Printer Connector Signals
'fhe
k.;(:ated on thr_~ n.::~.nc be1<.-:d of tb.t~ V.:\XuH-1tc. vvork.:Sti-d;ion, Tnbk~ 9-:> ]ists t,bf
nnts this t"'.0110(-:-ct~)r ~3upp(:.orts,

Moden1 Connector Signals
T1H: modem c•rnncctor.s are modular Tf<:LCO (telephone Iinel coffmatible connec·

h.ir5 !.ocntcd 011 the optio1rnl modem board. protruding through the rem·
of
the VAXrmite >•inrkstation. The c0nncet.ors use ;m 8-pin, ke_vcd modular hnusing
for ;;in HCn C jack lor CAl 1 iaek in Canada!. TnhiP 9·B lists the signal;, for ~-;
rn.odem. G•nnectr;r. Table !). 7 lists rhe sie;n[•ls for a h:mdset. connector

Pin No.

Signal. Name

No connection
~o ((HHH)ct.lon

iV!JC
TIP

Hu,;c

Ml
7

N.C'.

t-;c~t USf:d

TEL CO
SO'.lr(I)
TE LCO
return
Not llsed
!'.Jo conrtettion
Nu cc·nr1ettiun

~·U'

NP ·:~.onnectif.H!
No cnnnerti{ni

,,;t

i:>llC

·~..[ r)t tJ~Pf~

R!"~G

!'Ll,CO
TEU'O
>J,Jt c~~;;erI

N.C.

'TlP

l'-JJ

:.Jc! !_:t)nnt:cti~)n

?'\t, {'OnJ1~:ctinn

lt· 21

Progran1n1ing Example
The examples in this

..
sen:ti J;O
hard\vare nnd soft\.vnre handshaking protnculs

CAUTION
ln1proper

01· itnprupe.r open:t.tion of thL~

cte--vice ~_:an

Ct:Hi.se t:lw VAXmatt" workstation tu maifunctirn1, The s1'.npe of

mrnrnple is limited w lhe context
t.hls in.anuaL No other use. i.s intnnded.

i.n

Act.ivatBs the seriril. port and Interrupts

l--landies cht1racter t:r;J nstrriss~ons

ser out
re~tar!:

device int
De'1divat0s chE serird port and
Put~ a character _into a

put }Juf

buffer .fron1 tJ10 ~-tp_plicat.ion

puts buf

buffer frnrn the

Gets a c.harnct<'r from a ring buffer for Ute
'rhP :ieritd exun1nh:.~
/\Jl
vector entry
interrupt handier

tnt motin1

An interrur)t vector entry point for 1.J1e modein seri<.1! port

int

/\n inte«nipt vectur ':?ntry poin1. for the .'1t:ri;1[ pri.nlt'r port
handler

'i11rndleel

II- .2~

Seri.al. CommirnicaUnns - .Prngnwnnlng

Program Description
Cnnstuul Vuiue

Del"cription

P_ENAB through \·V01iD5

Define the line control register bit ndues

HDHVY throug·h HRL'.4K

Dctine the line st;1tus register bit values.

t-:NA AfOD through
f:..'.}'\iA -THE
.

Ddine the i.nterrupt enable register hit va.lues.

DTH through LOOP

Defirw the modem control register bit values.

RLSD through CTS

Define the modi:m status rcg;istcr bit vvlues.

HHS through Ut-:V OFF

Define the bit volues used to maintain the driver
stntus. The driver m.atus is part of tfo:> stru<.tttrP
type DEV !JA T.

CU<

ls divided by the desired baud ratn to give the
value for the baud rate divisor registers.

N 0 _PAil ihniugh S BITi'

Clarify the logic uf tlw fundinn. device

Serial Connnunie(lti<:ms · P.rognm.iming E:xumple

75.\!FN pecL'..t'.' 11elect • i
l1~JD

j·

~ranSFit

'";~i_.r::c-:

'i-

!:J

t-.:1 r,

2~~~dlt~g

ov~r~~n,

#def in~ EN.A .MOU
#def ::_LE:? E!\A _Hr~G

~-·y

8 - b '· ,, yi(j t.:d
·h i co we. .to
0 -·b t !_,>.,'(;, rd

/ +'

/ -~-t

p.h;:--

;-,1;)

rrt

~-~g

p2~i~y.

'i To ee
~

& iz~

r~c

~~P~~r

!l~~iog

r':~eiv~d nre~~

ti~s

Atn·t & ~ci r~y

eneL1.c

>'· i

j_;t.~

[!Y0~
0~0:DE

-'/

tr~=·~ n0.~-~- cm~~y

1·~

defi.ne ~ode~ control re~.later bit ·~alues t/

#define DTJl

OxOl

lld.,·fu!" R.TS

0:,:02
th;JJ8

#deJ1n1" DUT2
#define LOOP

/* data terminal r~ady
r~· :t"4:·quest tc- t.!ff"nd

'( /

/4 out 2 interrupt ctrl x/
/• loopback made

Ox.10

I* define modem status register bit ~a.lueo
#de-fine RUlD
ltde fl.ne

o-l(eo

#define DSR

Ox20

GTS

Ov.J O

#ddjne
!~

rec! l.ine aig1rn1 det:ect

j •

lldef in<! HHf;

Ox SO
x-off pendins flag
pending f.lag ' '
i* devl~~ close r~queet
1~

define

so~e

/+ x-on
I~-

g~netal

1 f-543~~00 I 16 - 115200
:-:-n.f:f (DC3) charactcx
/...., x-on
(.OC1) r;harac1;er
t

'/,\

re~ister

:)
)

•/

'/
-t·/
·~~

partt-~?

even paz·lty

/,, 0dd parity

2
:1

ti topped

constarits

program ~onatants used to ini•:iftlizc the line contra

l>define Nfi PAR
#define ELI'Ml.
#define cm_PAH
#ddine SC PAR
#define SS PAR
iHfoJj_m, S_BlT2

sending

/P.'. d-river .o-f'f line ~'f

#define CLK RATE 115'.WOL
lid'1fine x .OFF
Od3
#def 1ne x .UN
Ox i 1
!~

define driver st~tus bit va:luea i/

#def int' FXf!FF Ox40
#define F _XDN
Ox20
#dehne DEV .ct.S 0-xt.O
#define SWAIT
Ox04
itd<"fine DEV __ OFF 0x0 t
i

r1ng indicator

data Det ready
1~ ~].Par to ecnd

Ox-·lO

stick purity cJear

o~--::o4

Serial Conummications · Prngrmnming E.xnmple

H- 2:)

The stn.ictw·e type SL'RlAL declaies the n:l;it:ionship of the B:o'SO/\ UAilT rel;{
iswrs in I!O spat(\ The
accessed by the nwmbers ribl. and iehh
rfopends on the follf)wing;:
lf bit 7 ot rlw lin0 f'Ontrol
of the baud rah; divisnr uud
rate d.;visnr.

is !'et, rth! ~ICCCSSCS t.he lw.v f}ytO
:i.cr·esse« the high byte of the haud

It bit 7 1)f the Jin(' tontrol rcg-ister i~ clerix, rthl accr·~ses tbe rc·ce!,ve
register wh8n reading and the transmit regis1:H when
and
iebh .acces8e~ lnterP.1pt. enabte ''"""""'''"

•

The strneture type DE V_L1/\ T stores tlw dwractNistir::i of tbe individual. devicc>s, the current sta.tns. and the pointers h.• the bufhTs.

typed<Of r;t.ruct
{
uns i gned

dll>'t'

:r tbl

unr~:ig.n~3d

cha:r.

j ehh :

unnigned ·:har
uns·i gned

(;h2-1r

/i' receiv~/trans~it/bRud

low •;
int enable tag/baud h1gb ~;
/* int ident.jlication reg~;
/~ line ca;it,rol reg!ster ~;

j nt_ident ;
Iu1e_ct:z.l ;

control rogi~te1·
line status regletur •i
modem Htatue r~gister ~i

mod~rn

urw:igned char modern~~cti:J
ut~si gned cha.r l i !H?_ 13-t~t ;
unsigned Ch(t.:r.:- modf"t\i stat. ;

J SERIAL
stt.,uct

dB~J ~<let.

int

UnHign1;-C ln.t
unsign~d i.nt

pie:;
ir biL
baud;

uningnecl int
tmaignud int

JHLr-ity,

typed~f

{

SF.RIAL

'l.UJ.s.lgned

unsigned l.nt-

St-op_biiB;,
rt-~q

IU'Hl BUFF•

''pr hi.;

___ RtffF

p:rho~

UH:3if.!1Pd:

}

DE~l

__ d_!J::.

char

.D.JJ.T :

\?oid int on(};
irit~ _ off();

'in.t.

:Mi

i/o addreos of device

Serial Comm11Hl.c;itions

Pit; nux_ber it be}un~-n to
/* IR h1t in PJC •!
1 ~ deBi1-ed bat1d rat~ ~:
desir~d

unsigned int
HI~·4G

ba~e
1>~,

word size

DSR required flag •!

}Jt-r to inpqt.

ptt t.o otltpu
1~·

otat~

r1.r:.g bufJ +/

ring buf~
of driver

Tbe function dedce ;nit f:stabiishcs a known ;.tate for the 8:1,f>OA UAHTA
seriai <lr~vice. Two items of interest an• stick parity and stop bits. If stick
is selectecL the parity bit is set w the opposite state Qt the even/odd
parity bit. If more than one stop bit is seiected, the number of iitop bits
depends on thn word si?.e. If tbe word size i.s five dma bits. there arc 1 1/2 stop
bits. AH other word sizes generate 2 stop bits . These characteristics arc a function of the de,·ice. not tJw code.

da?ice.injt() - establish a known atate for a serial port

~nid

device init(pdd)

regist"r DEV .. DAT ,.pdd;

unsip;ned int

initial.ize seri•J port "i

pointer to device data •/

!• temp to hold results ~/

tbaud;

tmnigirnd ('.har tpar;

temp to collect r11sulta ·;/

IA pointer to SERIAL struct •/

cal~ulai;e

baud rate divisor

ewitch(pdd->parity)
{

case

tpar

I• no parity */

NO_PAH

rm .. PAR;

bJ'(~ak:

/* even parity ~;

RV PAIL
rpar - P ENAB ! P_EVEN:

c aii.<o

ln·e,.k;

c<>se
Ofl .PAR·
tpar -- P ENAH
b:rf!ak:
c:aaetpa:r

I• odd parity ~1
P_Ul!D;

SG PAR
P _EtlAD

!• stick, parity bit clear +/
P _.STE

P _.EVEN:

break;
case
tpar

SS PAR:
P EtlAfi

/•

stl~k.

parity bit set

r_snK I r ono·

br~ak;

/t deaired word Biz• 7 •/
Serial Communi.eat.iuns ·· Programming Exompk•

9- 'l7

8:
t,par , ~, \JORDR;
brei'lk.

C'lH~

•:as<' '1 :

tpr1r l,;:; l.f0R.D7

I* 7 ciata bitH 1

!t set utop bit~

br°'-~ak:;

Cll?.e

t•par

I- U!JRDG;

b!_.~Hlk'

t-inr · = 1.lURDc>.

breek:
it(pdd-~stop
].)$

;;,-~

bitB) tpar

S_BIT2

p{!t_i->baH(•;

iebh, 0):
oui;p(&p1~->mc)deJ1! ,r::trl.

LOOP)

outp(&ps->line .. ctrl. Gx80);
011tp{kpn ·>rtbl. ~baud);
autp(&pe->1ebh, tband >~ R).
outp(kpri->J ·uH~_ccd. tpa;:);
pdd->at.a1,_~drw

= DEV __ fJPF;

get

pcinter

~-1

/,.• int.e:n:uptg ofi
p~1t in louobacl: mode ~;
!~ arces~ baud rat~ divisor 4/
baud. rat~ d~v1aor 1.o l~v~P !
,~

baud rate di~iBnr hi bvte Y/
bita peJ· cl~arl µarity ~!
·~

}

fl- 28

shortp~-

Seriat Cornmunkalfons · .Pt'ogriuurning Exmnple

ti·anPm.i.t int tlfi

The funr:tion de•"i''e open prepares the <!river to hnndle interrupt:.; and the
device tn receive d1arnctern, Becmi.se Hie 1.no<lcm interrupt ha« rhe lowest
lt,y. \t is cnnbkd
for hardware handslwking. In ;.hat instance, it, rnitifiec;
t.he drh/(;r tf; n,:~start chHractcr trn.nstH.iss:ion~.

Settimr tho modem control ti'p;ister bit OUT:! connects the 8250A UAHTA inoutpin, to the 82f,BA interrupt input- This bit nrn"1, bP ~et to opernk a
cnvl.rt)nHJ.(~llt"

- activate aerial part and interrupts

vojd device .. op~n(pdd)

poi.utcr to

SERIAL ~pa;

Ps = udd·<>bas!":.

ifl\inp{&ps·>mcdPm_etat) & lDSR
d:rv t;_:-;;

eJst'-? _F1dd->ctat~_dr··~·

get sha1-tcr pojnter
re~eivP data buffer ~;
,~ clear Atatue flags
/<-:-: if har<lwuxt> handsha.l-:t: ·::;

CTS))

CDSR i CTSl)

-5 1,.JAlT~

/0c: rr:ark aB ot:
/:-{ ;nurk as not ok "''/

SUAIT;

autp(&os->iebh. ENA .. REC

ENA_MDDl

dse outp(l.:ps->iebh, r:r;11 _REC);
&~

p0·inteY to SERIAL struct

empty

il(pdd->etat_drv & HHS)

pdd->sta.t .drv

inp
inp{&ps >l3ne __ gt;al:;);

pdd-~~~~;;tat

data

d~vjce

/~ recei~e.
I~

imaak(pdd->pic. pdd->ir bit, ON).

Serial Cummnu ieutiomi

receJ~e

anc! li.ne

onl i:n.e * /
•:lr the Jnt.-,rrnpt mask

DEV flF.F

ou.tp(&JH" >~1nd<'m_ct:11, DTR!ltTS11JUT'.~);

j11et

lin• k modem •r

Aet modem co11trol bita

Progn1n1111ing Exmnple

'iTte function ...:er our prnvides t:i
loc£ttt.on tor rn<:1inrain.ing fff
inteuupt-driven transm1;;sions. lt abn provid(oS c; mnt.hoct for liohwarn
shake ''hanvcters to preempt normrd rbtn t.ransmissions. To prevent continuous
interrunts. vvJH~~1 t:he 1)ut.put bu.ffer is enipty', the t-r.nnsina. interrupt L~ disBJ>ied.

/·" aei~ou-t.() - t.;an~mit interrupt. staxtup and wa.Jnten.anc€
/ ;+.,.;c:f:;~ ;I<-.:.,;;;:.-..;,;).~'}:'-\<;

;; •,\..>!·. .:;,, *·-i··o

.t ·} 'f-''i-'. ~- ;-}.

* .',; :.; . :.;.,

::;o;:-f<·l" ~;,~·~: ).< ;f-• .}" :~ ,.i.; :·;,.,~,j--,·:i< +:of'"'\:: *;.:.;1' ~~t...J... t' ~}.

'* pointer ta devj.ce d~ta */
register SERIAL ~p~.

1,0 SERIAL atru~t */
!$ ~ha1artcr to transmi·t */

1~ p11J11t~r

!• get aborter poloter *!
if(i.np(&1>s ~li.n0_~L~t) l Ox20 &&
(inp(&pa->rnodem_Rtat) & DSR I I

ti terminal ready

* nr dsr not required ~/

! pdd·- -..,.:t e·q_<lt:r))

{
1~

pendiag x~Qff request ?

i_-

c ; : :; X _Uf.F
f},u~

c.Lear pending flag ~;
1~ send x-t•ft ~!

j ·

}
{
pdd->r::t~Jt d.".r;,~ &!::.

""r XON~

:• clear pendinK flog •/
/,:..: Sf:!n<l -i::> on ot./

,_ = x :rn.
i. Jag
}
el~~"'

/* terminal ready

request eharacter to Rend

character ta

Lf{: (ptld-->st~.t~.\l"r·;· & SVAIT))

{
1~
f(fl{~g
~1.B.f:';

s~nd?

{

devire_close(pdd);
return.
}

}
}
<'lE.e flag

}

else f'l.ag
if(flagl

{
/ < <>n>1 b le

outp(&ps :>iebh, inp(&ps->i<>bh)

!~ output character

outp(&pa->rtbl, c);
eJ:;e
outp(&:ps ;·]ebh,

tra.nsm Lt int.

I ENILTHE);

•I

/·; disable tnrnstclit int ""
jnp(<li'p!'l··>lebh) &

'ENA.THE);

}

Serial Communications - Programming E:xamph~

V- 31

·T-he .funct.h:_ff;. r~>.;.;J-:,?ti tcst;s th{~ 1iH/?~·n.ipL ent(UlC
rvpt.~ <tft"

(;;~~Lbh.::d

ri:

;"l_f(:

:n~)t,, i~:

to det,(tnnin~--~ if In.ter
c;1!is ."'·er (H~./' to r-ext-tu-t

d.r~·._,~,..::n tr(J_Il~nni:::~:io:1~.

pnlnter tn devJce 1a~~

l~S?J.g

'""' _1.nt; J! f ;J;

~~·x._c~:;;_t ~pd=-·~);

:uxt_n;i {f

l_T1e tuuctltH1s cont 1
the serial devke;;.

p;r_te1n

,_. rtid

}

DEV ___ t;.:;,T dt!-,.rrlat.f'1

c.e~,,;j_c e _ "_int

Ci.

and
interrup1 hand!ers call £? ccnrnnnr~ i.n.t.errupt hD:-r.dh-~r.

Tlw Ionction cfrcice mt is th(l major fund.ion within the devi.• :e driver. Jt
cnordinat.cs interrupt processing. fwndshake protocol, and periphernl
contwll.t'rs. For
,i;iven serial dPvic•~. this function prnc><sses all pending
!Hrupts during a
·
CPU intc1Tu1n ·rhis reduces th1.: ('.PIJ interrupt pm•>
essing' ovei nead.
Devict: 1:nmnmnic&tion errors are nor:.cd by

a qurstion mark 1.n the

strean1,
Llw contr,:nt;; of the inb.:rrupt idm1tificatl11n

vaid de¥ice_int(pdd)

!• interrupt handier •/

point~i

de~ic~

data

at,r11~t

value read

{

reg!eter SERJAL Apn;
tm,dgned ch<1r r . \'1'.l ·
ps ~ pdd·>baee
while ( ! (Ct~ ~i!d
C-

point~r

:Jnp(hpa->int . .ident)) &- 1))

to SERIAL

r~giater

/T get shorter pclnteY I
~bile lnt pPnd t/

~wit.ch { r __ ;/a_})

{
1~

case 6:

r~c~iv~

error int •/
clear errox •t
J_ t ·t;P_t."minn l read:r ~ /
ot dsr not reqtt.i.re<l ~;
I~

inpl&ps->line stat);
;~

}
b!."eak~

'-np(&yrn-,,.rtbl);

receive dAta l~Hdy int ~!
!-k read ~hHr~~ter ~:

if ter~inal rPady
or dsr nul ~eqlli.red

{

Jf{
{

k: HHS)

t/
~'

{

x-nff character

case X.OFP:

pdd->atat_drv
break;

SWAIT:

&~·

··swA.lT

ca;cie· X.. ON:
pdd··>ntat dn•
r·••fft.11rt (pdd);

/;~

x-on character ?

·~!

break;
default:

lf(rb_infpdd->prbi, r_val) < 1)
{

pdd->atat_drv Is F XOFF:
restart(pdd);

1~ aava characte1 */
i.f buffer near full */
1~ atop input •/
1~ restart if needed ~1

}

ehe .iHrb .. in(pcld-·>prbi., r.val) < 1)

outp(kpR ·>modem_ctrl

DIR I OUT2);

J~
/~

save character "'
no input pleane

}

!+ xmit hold reg empty int
/t transmit character

case 2:

ser out(pdd);

break;

modere statt1s int
if (pdd->ntat .. drv & HHS)
; ~. har·dware handshake 7
if((i.np{b:ps->mnrl;,m_sta.t) & ([)SR i CTS))
(DBR
GTS) .l
{
if(pdd·>atat_drv t SWAIT)
!• send stopped 7
{

case ()

pdd->ot1t_drv &=

·'/

SWAJT

r<:>st art (pdd) .
}

els<' pdd· '•:<taL dn

SWAIT:

I• mark as not ok ~;

hrf;~ak:

J
}
f'Ol (pdd- >p r) ;
}

S\•riul Conmwnications - P.rognunrning Example

!) - ;15

o~,~v(,&;pritl <>··~.H~-8~~-:·t•:i;;;::;~i'.'! .. ctr:_.

D~tp(~pdd

~}~~~e--~~.~:bil

()}

d.~~ice

oftl~.ne

0),
i~ nt~u~ t~ie
1·~

drive~

st~tg

jilter?upt - ~
~

cffJin.i~

The function p11t l,11floops until it ha-; stored the indicated ch;;rnct.er in an
output burler, Atfor storing· the c!wracter, .it ensures that the transrnit: interrupt is enabled. The companion function pu:s 1>!1f processes a null t;ermirwtcrl
calling· put huf at each cbaracter in the string'- The nu!! terminator is
not processed. .
-

void put_buf(pdd, c)

regj st er DEV __ DAT ·•·pdd:

/x pointer to de~ice data •/
/ t char to put in buffe1 ''I

char c;

put, char in output; buf •/

{

int :flng;
int r._oal

for(ll•g ~ -1: fl•g < O:\

/4 wait unti.l success

{
flag~

rb_in(pdd·>prbo, c),

resta:rt {pdd} ·
}

(+ puts-buf 0

/
:*.:/

- put at,d.ng 1n tc output buf:fer

t1 ~\r:ing

regi«ter DEV.• OAT • pdd,
char *pc:

while (
put. buf (pdd. •pct ');

into -output buJ

pointer to device data
1~ pointer to string

/~':i., ~~'hi le

-string not don.P ,. -'
/w do another cbaracter

Thn fonnion get bul nttt>rnpts tu retrieve a <.:harnxter from the input buffer H
no characters -;;n; ;,1vaH0ble, it n;turns a .J vi\lne. It nlso lwndlcs the inµut
handsba!rn proto<·nL

get; character i rom inpuL bui fer

/• S"t buf()

int get_buf(pd.d)
/~ poir1i.~r

to device data

char c:
int. flag;
fJ ag ~ rb .. out (pdd· >prbi, &:;) :

il(flag • 0) return(flag):
i f (fla;i; ~~- O}
{
jf{ 1 (pdd·>atat_dr~

/i· get: d1ar from 1.nput bu:ff ···/
I• no characters a~ailable •/
/* 1·00~ to res~art f l<>w ? ~;
1~

k HHS))

and 1·ecei~e stopped
software hnndshakc ?

~;
~/

{
pdd·~>;;:;.t,0t"d1.-v

i= F _XON;

Hct x ·on ilag t/

r·eutnr·~~(pdd) ~

}

else outp(&pd<J.-;,h,nie->modem .cl;d, DTfl.i !lTS: OlJT2);

r
flag ~ c:
rcturn(flag l Uxff).

reLurn cttn.Jactcr

}

{

.; -~· ;].- l

;rttnf.in"! BUF ,Sll 100
/~

#defi.ne iilWAl'ER 7S
#d~fine

J.U~ATEK

#de'f:ine COM1

PRINTER (81·.:R tAL

RING_. SUF!:- rb[D
uh~r

!~·

{SERIAL -'')O;.JJ~1JH

#define MODEM fSFRJAL y)Ox02.f8
#d~f :Lne

hnffer nca_r full value ,-/

/'-1·-

ban~
h~.~c

~ddreRs

addreBs

of
~)f

~arr1

rr:odt?m

* C-·t._OC.4.0
!~

ring huff ctrl

bufff3J[2 [BUf_SlZ]

etr\t~la

rl.ng buffo:r:s
de~~~~~

d~ta

tRbl~a

{
{

COM1,

i MODEM
{ PRJNTER

0, ., 9600, 8, NO .J'AR, o. 1, fn'b[O], &rb (1] , 0 },
0, :3' 1200, 8, NO_PArt, 0, 1, &:rb [2] , hb[3J, (t }.
1 ~ 3, 4800, 8. rm __ PAR, 0, 0, krb[41, krb [5] , 0 },

};

Surial Comnwninltious · Progrmmning Example

sed~1J data. It.
1md t.hen

The functlnn so drives tbe ex;m1ples by trnnsrnitting or
initializes t.he devices and data stnn:turns, e:'.ecutes the
doses the elev.kc.

eaO
{

static MESSAGE mso fl ~
{
{

·~~&-

ns~·ciaJ

{

''FL

Seh>ct the COMt port" }.

{

:~4

"F2.

Select the Modem (CDM2) port" }

{
{

·r

~~4.

~~·'1

"F3.
Hf"1,

Select the Print~r part" },
irans;n:tt 21arnpJe datn 1' }

{

2~.

R~cejvc

{ 10
{

I'·

}

. 24 Pf10
0 };

} ,

data'' },
F.etE-Yn to Main menu'' },

regi B t.<:~x :JEv·_ .. nti..I
int l.,
int

Corr.rr.un~_catia.n~ E.x:ampJ{"''

H ~

tnt (:ol:

I·

int ffaf,:
~inn: line[<; j ?.] ;

unsigned

iti~

rl~~ic~

it pc;lntPr Lo

~ ..f.H:3d

dnl;a

/v: loc-p c':nntru I 1/
/t lonp control ~1
di.splay poojtion •/

h(l1d Pt-a.i'-e of G!'U tF
1~

in;y_flag:

_!,t;

lin~

st~te

tc data

to holJ input

to bnTd G.PU If

f o:r ( i

pdd ~ &devdat fi

init_xb(pdd->prbi, hbuff[i] {Oj[OI, BUF._SJZ

H!WATER.. LOWATER) =

inJt :rb

>p:rbc, tbnf'ffi.J l1J [1.J

Lf{pdd->p:t.~::.

·-~::::;

O) e

0?,.03~

BUF,.SI:~,
1~

v~~tci·

baee

iv_1ni.t(s

/~·

pdri->Jr_b.itl;

d!~ Fi CB_itti t (pdd);

;~,

p0i1lt~r

HIWATEH

base

s ·_; (}y_ 'J():
intr_flng: lnt_Gff();
r~lee

get

~cctur

1.0ti~~TERJ;
i~r

maAter pie

for slave pie •i
allo~ed

i.nj_t interrupt visctu1·s
I~ init serial devi~e

110 interr11pta

tlevj~e_open(pdd);
iP~_nn(intr_flag):

/i ;iJ 1n;,-J ln.tc.r:rupt_;t=- !-/

}

line LO]
;,.;hil;s~(1)

1·

nu.11 line '>;-:/

disp.rnenu(mao);
line[O] D get_fkey();
swit.cb ( 1 ine [OJ}

/"· diflplay menu for serial example ~
/• get menu selection •
/• which function key ? ~

{

/* select com! port •/
&devdat l01:

!• get pointer to data •/

case F2·
pdd • hdevdat[l],
break;

/' select modem (CDM2) port 0 /
/• get pointer to data •/

pdd

case f3·

I• select printer port

!• get pointer tu date •/

pdd = k:devdat [2 l;

brea.k,
/ :..· transmit. sa.mp le te:-:.t

diBp_str(l4, D. "Press f4 again ta canceln);
i -: 0;
whileUine[O]

!"'- 0 11 line[lJ

1,,,

F4)

{

aprint..f (kl inf! [O], "This is U.ne %d\r\n". i-H);

puts buf(pdd, line);
disp_str(l.b, 0, line);
chk_dt();

di.splay date and time?

i.f(get.lrny(.Uine[O])) /r scan code ·1/
wbile( 1 get_key(llinertJ)) /• character code •/
j

bn•ak;

case F5:
/~ rccej . ve serial data ~1
diap_str{14, 0, "Press F5 again to cancel"),
col • O;
while(l lnP.[0] i~ 0 i ! 1ine[1] i~ F5)
/* F5 terminates */
{
1

~·

get._huf(pddj,

HL. :,. ··1'1
i. &~ Ox7f;
disp.t(16, col++, •. Ox07);
if (t ·z= ' \r · i I i.

' \n ' } col

if(col -~ 80) col
«hk .. dt();

/'" display date and t:unt' ·t .,i

if(get.key(&line[O])) /• ecan code*/
wb~Je( get.kay(lline[1])) I~ character code •/

Serial C1mn1.mnicationi; · Programming Example

9- 41

}
bre.a.k.;

cacie FHJo

a· i < 3;

for(i

i~+)

{
1~

pdd • &devdat[i];

devtce_claae(pdd);
if(pdd->pic • n OJ a
eJ a~

O:r:?O;

tntr_flag =int off():
iv _Teat(s + prJd~·>ir_bit);

.int_on{jntr_flag);

gat pointer to data •

cloae device when done
/A base vector far master pie
/* base vector far slave pie ~/
/;,· no :i.nterrupta i.J lowed •c/
/).: re=-~1tare interrnpt- vectors :.-.:
;~ allow interruptH ~;

}

re-t.u.rn:
}
}

Serial Com1mmkali•.111s · Progr<namiug

Chapter 10
Mouse Information
Introduction
The VAXmate mouse !part number VSXXXI is a pointing devke with three
input switches. The mouse has two encoders, one for the X axis nnd one for
the Y axis. The encoders have a rnsolution of 200 counts per inch. \Vhen
moved on a flat surface. the mouse monitors the motion relative to its position
at the beginning of the motion. Thu<>. the monse maintains positional darn in
the forrm of incrernental XiY encoder ('Ounts. Figure J.().J shows the mouse in
rel;ition to its X/Y axes.
l/

Figure lO·l

VAXmate Mouse IParl Number VSXXX!
Mouse Infon1rnHon · Hardware Dcscl'iption

Con11uunicatio11 RequirlHnents
b;;Jitl

l)ar,.a

8 dv_t.a bits deast

uborts t.ht b-~--HiSLcis;;:iit:n~ lnld pn)11:es;-;.t:~~ the ne~i.v f_:ornrnun<l. If the rnouse re:ceh.:es
~1
thf~ ;::J1a:rncten;; of a
1.'epnrt, th_e n1011sf.~ rs cofl.sidert:~d to
bt·
{.U:d ~~ borts r-he rept1rt,

::;:s,ynchr-onou~"}

seriai inJe.rfl:-H't_~

f:ojn_n:ttnif:;Jfions I1:~_-erfnee}.

,Additional Source of lnforn1.atio.n

1\'iouse Conunands

5:2 Ji

w- 2

~~O 1-I
:,1[;

Prompt. .Mode
Incremental Stream .M.ode
The mnust· ha:<> twu upt:rating modes, prompt nwde and incremental stream
m<.Kk. Jn prompt mode, whirh is the powerup default, the mouse geuerntcs a
n::p1>rt. in respr.mse to a reqne<;t mm1se position command. ln incn.>m1.mtai
strparn rnocle .. '"~,/ht~nevf-'T the n1oUBP r11oves it gcncn]tes a renort ol that rnove..
ment. l t also reports a
in but.ton positkm since the lase report. No
report is grJwnit,•d ·when the mnuse is motionle'Js and no butwns h:we been

Request :Mouse Position
The rn•mse responds to this i:omn1<ind
1ng t,(1 pronipt rnotte_

sending a

Involrn Self·Test
T!w mouse responds n; this connnand hy exei:uting a self-test and then sending
a '>'elf·te'<t report. Self.·test leaves the nHiuse ln tlu·' reset or powerup swt.e.
During; the '.Wlt·test. auy d<ita. sent t.o t.he mOU$(' is ignon~ct until th<: l.ast.
nf the s:eif·tcst rnporl has been sent by the mou.<;e. The 4-byte sdf-test report
consists of a
id••nJifkatinn code and a 2"byte status code.

Vendor Reserved Function
The vendor reserved funcl.ion is ;-1 2-byte command. the A8C:H charader 'Z'
followed by ;rny printallle drnraeter. This command allmvs vendors tn add spn·
cial mou:H; functioos.
. these functions arc for mrn!ity nmtroL The
manufad.1.m:•r determines these functions. which may include transmittrn11; srw,:.i;:ilized reports. These e<lmnwnds nw.y not JmJude new inod('s. On cornplet.i<Jn
of il vsiHkit· n'served funct.inn. the mm1se must be rest<ired to in; pn'vious stote.

Mnusc Infornwtion

Hardware Description

lO- 3

Mouse Reports
The mouse c;,in transmit two reports, a

position report and a

st>!f-

te<;t report

Position Report · Byte l
7

RIGHT

mrrrnN

Bit

i)escript.ion

ti '''

1 ''·

bit for X-axis displa.cementi
X··axls dispiacenwnt
Positive X-axis displtwerncnt

0 '"

1 =

LEFT ROTTON
0 "" Switch
1 -..:~

S·v,rin:b

.MIDDLE fHJ'TTON
0 c"" Swl.trh
1. ··co ~witch

HIU HT B trTTON

H} ·- 4

0 =-

Srvif,ch ODC':n

l _:::-

S~·,v:itch C_~nsod

Mouse Informal.ion - Hard wan:) Descript:ion

Position Report · Byte 2
7

X-··AXIS DISPLACEMENT

Bit

Description

Always 0

G·O

X-AXIS DlSPl ,ACEivTENT

The X-axis displacement is measured in encoder counts l'.200 per
inch). The vallle returned in this bvtc i.<; the distance moved since
tbe l.nst report.. In prompt mode, if roports are not n•quC'st.ed often
mwugh, this value can overflow. If an overflow occurs, no indication
is given. Bit 0 is the kast sig-nifin1nt. bit.

Position Report · Byte 3
1

.. ·----···

Y--AXlS DISPl.ACEMRNT

Bit

Description

fHl

Y·AXTS DISPLACEMENT

The Y-axis displacement is measured in encoder counts (200 per
inchL The vJlue returned .in this bvte is t.he distance moved !'i.n<:t~
the last report. ln prompt mode. if rep1xt.s <ire not requested often
enornrh. this ''tilue nm. overflow. lf an overflm-1: r.lfcurs, no indication
is g-i~en. Bit O is the least signifo:ant bit.

Mouse lnfonnation · Hardware DPscriJ>tion

Self.'I'est Report - Byte 1
..,

FRAM!'~

j
I

'~·.-

.REVISTiJN NUMBER

SYNCHRONIZATION

--···--..-C·--····-··

rHAM!~

,_,,

SYNCHHO'\JlZATIOJ\

Report · Byte 2
5

Il.' ______0

MANUFAC:!.'URKRS IU

,___J ____ _

'1~G

I)t-;\1 J!:-.E f~f)J)f,
/!.""_h';·,~nn=; 0010

_l,........._._ ___ _

r
I

!
-- ~

-·····-·-1

-~-

DRVfCE CODE

0
L--~ .

"L-.

Self· Test Report · Byte ;3

Bit

De'itrtptiou

EHHOR CODE!:
OOH ·"" No error
:J.EH '·"' HJ\l\l or ROM diecki>um error

:uni "''

Button error

Self-Test Report · Byte 4

Hit

LEFT BUTTON
0 = Switch
l "'' Switch

J\lIDl.lLE BllTTON
Switch <'ofld
l .; Switdi ;'.losed or fail<_>d

I) ~'

·'

RIGHT BUTTON

O ~=.

Switch .go(id
Switch clm•·~d or failed

!Vh1use InfnnnatJou

fJard.wi!I'~

rn- 1

Serial Interface
The serial interface is u S!GNETJCS SCN2GGJ Enlrnnced Prog:rnmm"blc
Communk<itions Interface Table Hk' Ust.s the input/output O;Ol ports tlwc
a•:n;ss thf' serial interface

H.egisier
OC40ll

Ri~ceive buffer
~rr ru-1stnit hoJdi_iJg register

R
\V

OC4.1H

OC42 H

R.'\V

OC43H

Hi\V

v,'
Command

The Syn L Syn2. and DLF: reg;blers are not wmd.

l\focte
.l. and 2 are accessed at the same I!() address. Head
mode
l and t.lum reBd mode register 2, or wdtP mode
J and
write mode registGr ?. Mode
t must be" {1Cces'!ed to
nccess modt>
2.

Tra:mnnit Holding Register and Receive Buffer (OC40H)
7

TRANSMIT OR

RRCEIVE fMTA

Status Register (OC41H)

ATA -IDATA·--·-r··
AMIN"f
GOVERRUN rl'ERROR
.ARITY - DATA~.
R~RDY-· -rf~DY-···
CARRIER ERROR
SET

SET

READY

DETEC'f

- -----·~-

Bit

----~- ------ - . ' ·-------- -~- - -

-· - -- ~----

_________ ]

RiW [)cscription
R

f')

-~- ··-

RF.ADY

CHANGED

D/\TA SET HEADY !always l 1

DATA CARRIER DETECT {always 1!

FRAMING EfUtOH

o""'

Nonnal

1 ~"

l"raming· error

Thi'> bit I« cleared bv disabling· the rnce.iver, is;.uinl!; the reset error
command, or ri>ading the status register.
·
4

OVERRUN
0 '"'
I

,.~

Norm11.l
Ovt'rrun error

This bit is de.ired by disabling the receiver or iflsuing the reset
error command.
H

PAH!TY ERUOI!
0
Normal
l '~ Parity error fif parity <:::hecking is enabkdl

This hit is ck;ared by disabling the receiver, issuing· the reset error
command, or receiving another dwractf>.r.
2

n
B.

DATA SE'.T HEADY CHAN(JF;D i;.dways 0)

RxHDY - Receive Data Readv

0
I

Receive buffer is empt);
Rcr:eivc buffer contains data and an intcrnipt is pending

This bit is de;:ired bv reading· the receive buffer· or disablingthc receiver 1comm11nd register bit 2l.
Txll.DY - Trans1nit H."!d!ng Hegister Henrly
n ° Transmit holding re1tistCo·r busv
Trnmm1it holding register ~'mi)ty nnd an interrupt is pending
0·

This hit is dean'd bv wridng: t.he transmit holding
<•bl.ing the tr<msrnitt.er innrn1Jrmd rng;ister bit l)i. ··

l\fouse Information · Hardware Description

or dis-

10 · )}

Mode Register l (0C42H)
7

--e·-

0
---r--- --

MODE AND BAUD
RATE FACTOR

Bit

H<\V

7-G

H/\V STOP BITS
00

- ---L-----

invalid

Hi\'V

HJ'.V

PAHITY TYPE
Ortn

o :. -:

f',\JUTY 1. ONTHOI.
0

:1 ~~

R/V\'

dis;:ihI'."d

c·.

(;!l:\R./~~"{~~'"f·_EH

5 b~ts

G.l
tO ::::.

G i1jt-:~
7 bih:;

L.ENCrrJ-t

\lode-

2.
\.\'heH

;-,EH.

rn.nd.f:

Mode Register 2 (0C42H)

--·-·-'-.. -A•-····-

Bit

;:~ 0

B;:\J lJ fL·\·rE
fn.;e Fr;:.1 bl.e I fl-J

Bit.<>

Baud

3-0

Rate.

O!lOO
0001

lH ts
3-0

naud
Rate

0010

75
llO

()(ill

134,j

1000
1001
1010
1011

OJC!O

150

1100

4800

ouo

300
61.)U

HlO
1111

'l600
19:/00

cn01

OHl

'JO

1200

1800
1.000
:2l;0()

3600

noo

lO u

Command Register (OCMffi)
7

-------

--,~--

!OPERATING

----

MODE

L_______I - -

0
r·--- ---.

Rf~(.:JUF. ~_;T_._ R~_-_,_,:-,:~ YN~.u_~_-_ I _- ~-~E.i:

I!xKIT II

.• ...
_1
__
- _ -·lr_g
TO SEND[
J':RROR
.ASYNCH .-. ri_{:(_.·;g:_·
CONTROL ·. DTR.·

·-·--·-- ______J_ --- .-

Bit

R/W

7-G

J1/VV OPl'.:RATJNG MODE:
llO
Nnnrnil operntion

j _____ ...

n·1

}\~n/nr~tu:onrnJ~~ tautornflti.c ecbo rncKh_•!

l H -.

L'irai

---

CONTROL

-"~"- ·~-- -

back

fl/\V

n .:--'
J

,-.

~::::.

EST TO SEND
f'q.cee. rt·<ruc:st to send c~ut.p:Jt
triii:.;::ibh~~
Force rcqu'.:st t.o ~-~E-'nd 0UtJ..a1t lcr1.v {enuhles

huffen
t;uffor i

The ~oGt!l El'C~l rws a huffor
l-1f':t,\veen tl.ie interrupt output line ;~ud the
twller
This buf.fr•r is controilt•<l
Cl.
enabk::s
26H'l EP'<:I i·nten:upt. nut.pur, Hne

RESET EHfV.lR

i -_- ;
3

H/\V

g;\y

H/\Y

.SYNCH/ASYN(:H
0 =--

Nn·rrr'l~1l

r-·(1n.'.f:

:-::

break

REt'.EfVE COY1 tHJL
0 ~ l)isabie rpc~_~i-;_.f:•r, reecive
t:':nabi.e te~civ(~r, receivf:'."

find statu.s

l.rit l

~1 n!I ~~ta tu..':

bit 0

DTH · r•ata Terminal

'::CC

L ·-=·
0

Heser t~1Tor

F1)rc{~ data

t.errninaJ

FUW Xl\tl.T CONTHOL

Tnmsmit Cuntrn!

Lnabic tran~rncrJ.e.r. tnn1sr:E~.t int.enupt. and ~~ta.tu~
biL 0

Wlwo

....!

base valm~ of :loll. In addition to thu base value, hits 0 and :i (tnmsmit and
fe('eivf' cont.roll musi. be appli•~d as required.

Mouse Inforn1at.io11 - lfa.rdware Desniption

i:J

; nter1J:·t!f-! ng t:.1e L:1,:U.·f~fi ~~

thD rr~(JUS-,.:.'. ~TF;!;;_cl'~ t~,,,

th) ~c:··t:::~.~n,

c.r

0::,

.~~i~~~- ~:'~ j~-l.~J:~rfr1cr; {(}~· i~l~X~!T.L;;Jt dt"!''/f7::C,

..,:n: I'i .~(~ ';Jfl:.;-·· .~_,_t,i(Hl~i,

f~(~fine

\.:h{; rnr~;.1: c f<.;-: ·::f•!~.cno
t-b(~
n·~_fJ T~)f~ -~< :'lfi' d.:.;fir;f' \'i~H l-:'~t•S \·-a.:.nes Uk(;d i.D

#int:::1ude-

"":rb~h' 1

#in{'.::Jude

''kyh.h~i

th_nclude '1 f1zamplt=" h 1i

#d<"fine 1~()USE_fllRT (MOUSE _UART "l Ox0C'10
#defi.ne MOUSE_PIC:
#de:finll' MOUSE_ l!fl' -.
#define MOUSE ,lHH (h'i4

Jfd<>f iirn MMODE
#ddine P __ ENAB
thief :tn<> p EV.Ell
#dt~f j n~

P__ onn

#def 1.nt• \JORJrn
#define \,/()}U)7
fldefine WOiW6
!*define wDRDS
#d..,fine S_li1T1
#cle:ftn~ s _BITZ
#de:fitw Illl4ROO
l"fof l.Ii'i' CtKSPG

o,'.cr;i

/* b'lsti add-reas. of moune -"f
/ 1- PIC that handha rnoulle */
m01Hle int, requeat lirrn "rf
!Jai:ware int vectrn location '-!
0

Ox10

Ox20
OxOC

OxOG

Aynchronous 16X rai:.t:!
/;;-: Enabh parity
I Even pa:r i ty select
/·f Odd paxity aele(::t
/·>i<- 8 bi.t chu:11ct(! ~a

fhrOA

OxO-::i
O:d)O

(,4'

7 b:it chax11ct<'-Cil
6 bit character:s
b bit chara<:ters

"'::/

:i:-/

.;;../
't:,/

:f'./

"
oi-

0;{'10

!• One atap bit ~1

O:xGO
(hOC
Ox.7!1

!* Two atop

bi~a

/ ~ 4800 ba•1d ~
'• 16X clcv;k '/

/ ,_ SC:.12661 atatns register bit masks
#<ie.f .i ne
#dr.f .1 ne
!l'define
ncte-fitte
#d<•fine

THRE 0>.. 01

ftDR!JY Ox02
Eft!UJRS (h.3t\
PA!U'JYERR Ox08
OVR1l.TWNERR Ox10
lltJeJ ine FRMHNGE!l.R 0.•:20

/$ Traoamjt holding register ~• empty •/
!~ Recc1ve holding register ia full ~,
P~r.ity. av'f'·.rJ:nn or framing err::>r ~/
/* Parity e.r..ro.r ""/
/ * n--~~~rrun error oj; /
;~

Mouse fofnrnwtion

Framing error ~I

Progn1mming Example

#define TxEN
ltdef :!tH' IlTR
#def in<> !h.£N

OxOl

/<~

Enable transmj t;

Disable data

Ox02
O:x04

xeedy

o:•/
v-

i* Fnabte If>Ci!'h•e control ,.;

HREAK Ox OB
#define RESET Ox to

I• Dis•ble brea~ •/

lidef :ine

#define RTS

COt'-~t.rol

ter~inal

/Jc Enahle XfJfH'!t stat·ua ?«-/
ins (1101·maJ ly on)

0f20

#de:fim: CMODE OxGO
#define CMND_REG RTSf!l.ESETiRxEt~

/* Command mode {normally 0) "/
:" norm<d cpenit.i.on. RTS~1, rec ern1.l:il<!d ,,/

•<!define SELF. TEET ·r·
#define p MOOE
'D'
#deHne LS .MODE 'R'

;~ prompt mode
incremental stream mode

•1

'p ~

/<t-

l£-q~i~~t

ptH:1it.i(~!i :r. ~poy-t

·-"

inaek any header hytf".

~-/

#define POS_J~EP

#define IESTMASK Oxen

/ 1

header by1;e i.ndicotor ~;
!• F~lf- teat hRoder byte maslf 4/

#defi.n<e HEAOER_BYTE 0>.80

#define SK!FTEST Oxi;O

/-*· p,:,sJ ·ttnr.i r.epnrt

#define POSR.f.l' 0.•:80

!•

#define IHGHTBUTTON Q;,01
#defin~,

MinDtEBUTTON 0.':.02
it.def i.ne. l.EFTB\fI'TGtJ O:>c!)~i
#def il'.H, XSIGN o,; 0

10- lG

h~a{h~.r

r~ght

byte

n~a:ak

>r-/

bu.tton maslr 1/
rra1~k

1:/

!* ~jdd1e bu~ton rnsal~

l.cft

b1rtt()~1

/'· X-a.dc Higr, hct ""'"'k ,;
/,..,_. -"{-?Axir~ siF;n hit 1H.tifdk -!-.-/
eelf-taat byte • 2 error tvp• mRsk ~1

self· teat bvt;p # 2 error type niask *;

#define YSlGN Ox08
#define RllMRAM_fllll. Ox:!;,
#define Il\FTTON_J!.Rll. 0.<:3d

{
urrn L gned char hr :

/i·

t1nsi.gned char ;;1ta. tun:
uu~d gned \,:ha:r mode;
un~i.gn.ed

t.ransrrd t/rec~J"J? holding r~gister
!
ntatus register
~ mode r~KiBter
coi~lrr.and

"=ha:r comma:tvJ;

'4../
I
~;

X"?p,;:Lete:r:

} MCUSE. IJi\lU ·

typedef struct n1ouse._dat
{

f\Hln BUFF
RHlC BUFF

;::. tiase 1/0 addT,,SIJ of rlevi_cB ,.·:_.
.,,
pointer to input ring buffer 1Hructure -t~ /
/
/:-· pnintt.n' to 01~tpnt- 1·in~ bu;t f e:c o:t:r·ucture ,\•/
_

MOU::llL UA!\ T
·>prb L,
J·_p:tJ)(•;

} MOUSE. DAT;

/,..

#d~f :i31B BUF .SJZ lJ'IO
ftdeJinc HI\.IATF.R 7S
#det inc LOWATF:R ?.5

<;bar bufff2](BUF.SIZ];
unsigned char cmnd .r11g;

size of buff era *
ne.ar fu.ll •Jahl<' ''/

/~ring buffe~s
!~

value t.o wrtte to command r·egister 8/

MDllSE_LlAT m011se .data ·- { MOUSE_f'ORT, hb(O], lnb(1) } ;

Mim.se lnrornrntinn - Progrnmmi11g Exarnpl.•'

Hl- 1.7

{
r~p,:i Bt.er MGUSE~DA r -,,pd.cl,
i:e:.i;lst.e:r: MOUSE .. lLl\RT "pe;

/;J pz}inte:r to mtHJ.tH.~ d:~.ta
to ~ou»P Atruct

& pcint~r

/* pain~ tc driv~r data
!• aseign bAa~ address •;
/

r trd ~~La j iZ<"

1 ing tx1ffui- ~"!:-2'.·uc+~u1:f;5 -:...-,.:
tn:it. __ :rb('f'idd-~>prbi.. ktn!tf[OJ [OJ, BLJF_SIZ, HI\~AT.ER. LDWATEit) ~

init.."rb(pdd--·;"prbo_, &hnfff.1] [0.1. !JHF SI7., HlH/\TER, LO\JATER) ~
/._,.

~sy;Jc

1f)f

~r;_ab,,!_f_.::

par:i.ty, odd pa:ritiy~ tHghtbi1 tih.t~.c (JJJ.f: at.op bit
! P __ E!'lltB ~ P_JJDD ! t!Ot'iDr; I S_ BlT1)

-:-n:itp(&ps->!i1:Jd-?,

r~MUDE

n~1tp(&ps.- >ro;;Hie,

BD480G

! CI.t\.SPt} ~

~::i:ncL.rt:'!g

.-:-:

:J~J-tp (~pc

:-...corr:nand, 0':tnd_1-e f).

/ -"

G~~t·~r;_ PEG,

.,,_/

16.;·;. ,::lcn::::c 4800 baud ;. l

in~t

to normal contents ~1

}

NOTE
initL::f!L.-.nti~)n p-r~uCl'\S.::~,

t.o tLxnsn1it nr rf.:~·

it. i6

char:;;H:ten-::. "fhe rnonsc· injd.aU.:u-.ttioD fu.ncti.0n docs<

nnt accngnt- fnr t;(n:s

open

th~

er1»hle interrupt

1noase ~t

inpu~

!•

eend __ to __ mouae()

byte val1,e

·transmit

{
:r'egi s t~r- MOUSE_Dll T >i:pdd,

1ntr __ ~ tlg :,

/* poj_nter to moue~ data
pointer to ~011.se Atru~t 1.;
;~ hold s·tate of CPU IF -/

pdd - &mouse.data:
ps

pdd->ba~"';

~tuJ.,.e(xb~ . ln(pddT·>µx.bn.

intr_ flg

cmnd reg

•.:) < 0

-...;aJ t

point t.o driver data *
asAi.gn base add1:~sa ~!

unt i. J stored Jn bu.t f P.t

,;· .•-

:, diaab]e CPU interrupt •/
I).. t,(> er..t:!bJ e t,1-a1u.rnd tt tn

rnt_oHO;
TxEN;

out.p(&ps ->comma.nd, ,_mnd_reg};
i_nt~. on { J.ntr ~fl~:):

~nable

trnnR~iLter

/ ~'· t-;>1'.1"1.ble CPU

intf'~"tl"'lJYt

}

_l\·fomw hlformutinn · Programming Ex11mp!P-

~ !

h.;:I!}tl'l.t..,._1:

¥/

i~· poi.nt.er tu ~ouse dat~
pointf'r t.o MCF8E_)Jt~H.T g tr~1c ~-;

~-.; /

read ntatua of port

re~iPteT

MOUSR_DA'f ~pdJ~
~OUSE UAR'r ~pa;

H.nsl.gn·~-tl

cha.r -'.- ·

~_1t!:.:;;1 _ip:ueC.

""tl,n :r·

~eg·~ste~

·1,ntex-:rupt

t.i '.

g.a::rbdR-2' cha-ra·::t-er '"-:; x/
~:1'"d~f!-a15":' cJ_1arac tt"r ;" /
iB the-·re &'1.ytl,ing tc' rra?~<l l ·f. .'
~~~d ~nrl st0re in ring buffer ~i
/'r bufif!l geltj_ng full ? .,._f
.> -'":

6 ~ J~pl&pa-·->bT).
~lee i.t(s & RURDY)

/·"-· .read

{
>hr))

J-~

outp'~~P9

>c{~,:n;,au.d,

any

~ha·c&Lters

trarLa~itrer

char~cter

to tranttmit

/-w

rli.s~b1€

~rite

the

:::~n:vt~-;.11~5);

~ni !~M~)OSE:_ Pl.C);

rnuUn-c· ccn~1d ~"'h{~ck :h_n treern_n1 en\Jl'S; nut-- it d1.1P;:~ nnt
h.:3.;.; :.• flxcd
t(:iu,~1t.
chur~:wu:;r:~ ~-1r-(1- dett:cteri ~n d1e roj:~nrd ciJll~~ccion p~rrt of t.!:H;' rn.qu~:t"L!
tunc<:.inr1
~J1nc.:

H;_::.,_~::!u~·e (~~i.::.J\ 1nn~-~~;e :·€po~_-1-

!• ~ouRe_cloae() - deactivate mouse port interrupts
~oid

mnuse_r.l.osc{)

{

reglst"'t MOUSE.DAT ·'pdd,
regil'lter MOUSlLW\.iH' *PU:

~ point to dri~er data ~1
pu 1, rnouae in prompt mode * '
./<· "'a i.t unt:i l rins b1dfe:r empty ., /

p<ld - &:mour•e da !;";
B'-'nd. to_soUS<' (p MODF.):

/ 1·

~hile(pdd-->prbo->count)
rmnd_re~

CMND_REG &

!b:FN;

/·' dieabh' r<>cei\'er and tranf'.mitter '<i

I* assign base address

pdd~-_; .. b~8e;

o·utp(&ps->ccmman.d,

I~ pointer to mouRe data ~/
point.er to MfJUS!LUART ntruzt. •'•/

cmnct~_regJ;

imMk(MOOSE'. .P.tr:. MOUSf._Hn' fJFF);

J~· writ~

new command t/

/,,., disable tnte:rrupt :input "':-/

}

Mouse Informal.ion - Prngrummlng Ex111nplc

10- 21

st~~i~

MfS8AGR ~~aus~i:.!

{
J 1 34,

11 M~11~e

~.::_~i

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~Ol_lf-J;_~

8~-e

X ,irid. Y rht.-q:.JJI~.-cmt:z-':..tr-;, 1 ! _!_
s~21c,:t

bc_x. u.r.ttl

Ex~-'ti_.l _,_ t:- ''

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wi.th le.ft

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x s~al0i' J.
x sc~1~:· },

J.D~rease

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~ncrenn~

24 "[
{ 1'' 24' ,; 1

t~\

G~l.-l.'B,rn· tc
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n

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:.:<;, },
'.';;;." }

~eglster

M~JS~_SAi

f'~~'i~tL:r

r~;tH..H~S.

:.rR·z

?pdd;
~d-• ~

. buit [30j ·

ro~ poo~~lcn

'.(--

".':.r"lJH~
/=~
/--~-

text

p~:~~i t tc~;.

rep-::t' t

J: U1g

end ~cu~~ exarnµl~ fJ.ilg
/4· et~at.e t_,f Jz;:~1: Lut-:.u.u
i:1pn~:

~b90J.11~e

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t:-ufi~~:

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c:a~

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ct! c111aor 1n

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~!n.S:>d.r:r

c~:unt~

curs~r

)'. ·fix! f'

e:1c-:·tler
1~

of cursor

r:G110~.:-~•

~~cod~T

£:1_-aJ,;:

p{-"~-:

~~~:n~~

~::o_1.H.~:r~
~~!r·

re~

-+'/
~;

H~n.lgn

b~s~

Rddr~es

cru

i:nt_ofi(),
v·_1nit(~OUSE,_J~~I) ·

rli f'."::!b 1.t"
iI::tt:~~·rupt
ini ~
::::.;.tey:;..-~:..g;r!; ~~;~~t::t-•.;-J~H

;

·,..
r- f

r;:t)Ur..<t? ... :irdJ1 (J -

isnu~

s~lf-t~st

i;itr_.flg = ~~t __ ot~{

di :;:o:.\':d:~d.::? C'Pli

O;
b.iJ;_ en i, i r~ t 1.- _ :Ll r,J :

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t.·!m;:: .f}ag

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ti~e .. fla8

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-(
S'EL.:~T}~if-;-'; / -1

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,;,,

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tir:.!.J~

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n;-::·: f ~ t:F:;.-it.
£~.:ii'.8 ..;

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b-~~"t?

udd1.~.ions)

~vp~r!~

,.. "

il~~

:tf:o.·pCJ:· i:

bytes

·r: /

dLap_151tL(1';~i

~iS.

&0>..buff(O]);

8b{n!'l

co:r1t.inu~· 1 ).;

dLsp __ s.t,r(t3. 3Si HP·.res-11 flO t(J
'.<'hlJ_,.(l)

j_f(get_jce:,(&:icJ,)

-~-

1 &&

l~h

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/,;: obow hrdp mensa_ge >r/
b1:ea~:;

1'10)

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el~e

{
di. .sp JT!OIHJ ( n:mcuse) ,
<'::ursox __ <nt t

:t _<-:ibH

.' '
pt,.s_rep -.: .FALFE;
c:nt .r<'q

dJ.splay ·:,.b.e ::-r;_oua£-> menn -"" /
"-;.. nrnke ,,,~uxsor vJ R.ihl~
!

;~~.a.On) ,

ph " &L hn.ff [O) ·
whi~1JI(eu<i ...Jt:c =~ Fl;.tSE)

:~ reset 1.0 j.ncrPm~ntaJ. str~am moda ~!
set bvt-e ca1:nt reqt•ir~d ta below z~ro ~
t~ no JiuAition ~eport y0t ~f
in:it1"talizr: pf',.intel to i.nr:inf; b11ff~r ,____/

{

chk_dtO:

(:beck date and time for upriate x/
1~
try to 1ead mousP +/

bQff_ctatP ~ Tb_aut(pdd >prhl,
tf(buff_atate ~ 9 O)

/~·

~-/

mo1re to beglnning of buffer
to next byt~ 1n input buff~r

dj.d the rotH.au; aend any·tbJng

(

if ( ~pb !/. BEf11JER_ BYTE)
{

i huff [OJ ~ 'Pb;
pb = b.i_buH f1 l;
if ( ( J _bn.Lf toJ
{

/¢

re~et

t~ype

/"' 1·~ma.inlng Cf1unt r~"-jU.lred_

:i'../

PGSREF) /

,,
h~1.·•n:-

1'JW£:

h~~ath~:r

~:.b.gcr.n,.~2r

h~(;fdcr

byte f ryz: pn±) it. ion repo.rt

"1" /

}

antl1ing ~ls~ .la ~~. error
set byte cou11t 1equired to

belo~

zero t/

J~ U0 po~itJon rero~t

else if
{

FAL<;E;

pt~~_rcp

cnt_rf.:'q
if(·

/>.~

~annut

bP a J'Ositton

rc::et b rt.(;:' coun.·t I:equ1.cr:td
0

t(1-

1~pnr1.

bel(;~'

ze_:r-.;}

'f'

_!fd~t·Lun

:f1a?.:

:;1,./

cnr_rPq =~ 0)

r::o-·<'f.~·;'1

t.;;ip

"C;,

i __ lJLLf ~ fj ;

,.,,

cleH-: niou-B-e-

g<!t. X" aJ<: j fl ir1cr(~m_ent ·(: /

if('(t_buiflOJ & XSIGN)) tmp
x__.;'n_ts

/.~ .

tmp;

sp.rlntf(o_bu.ff,

"~~4d 0 !

dir~p_ str (18,

42 ~

tmp ~ x cnts

I x_ncale!

/w check sign bit •/

-tmp;

ac<:\Jmula.t~

tmp);

X-nxi~

~,nc<:'dcr eount1J +/
/-, cnn\•e1·t to a strJng. ~/

/ ~ sho\11.1 X -a:x:i a in-:reroent

n __ bn-f"f);
/-~

enough to eho~ ~otion

-":-f

i.f
{

cuts -~
s(;alP
tr;;p .:
... abe 1~ tmp;
if(x_abe < 0)
_abs - O;

-,.~

ii"

if(x .. nba

moved _; ._ 1,

/ 'i'

remove scaled counts *I

arld to absol\;_te

po~tt Jon

/+ no off-screen. mo1;ion ~:/
! '' no off -screen motion >•/

79) x.abe ~ 70.
I* set flag to update cucsor poaitian •;

}

/i· ge~ ~·-axj_s 1ncre1~ent k/
tr::p ~ i_buff f2]:
H(!(i_huff{O] & 1811.Hl)) trnp
-tmp;
/• check sign bit •i
y-axis encoder counts ~re accumulated negatively to inver~ motion k/

-= tmp;

~-~nta

/• accumulate Y-axis encoder counte
I~ convert to a str-ing i·/

npr intt (o .buli. ";'Ad.", tc:p):
diap_str(19, 42, o_buff).
trr:p

c:.:

:/_.<:11 t.B

1~ show f axis jncrement x/
/i cnnu.gh to Ahow moti.on 1 ~;

J.f (tmpi
{
/.,,~ remo"'Ie Stca.lE?-d cotJ.nts -~-/
tmp;
y ~- cnts
y_abs +~ tmp;
/-< ~1dd tn absolute position "''/
if(y abs < O) v nbo • O;
!~ n~ off s~·reen motion *I
/•no off-screen motion ~1
if(y aha > 241 _abs • 24;
/• aet flaK ta update curnor position +/

}
5.f (mo':"'d)

m·; _c1u-sor(y .itbs. s __ abs);

/4 display otata of mouae buttons

for (tmp -- ff.FTBUTTOil, row -

~;
row~'

''; n1w < 17;

tmp >>-' 1)

{

if(i.buff[OJ & !;mp) dil,pstr(ro1e, 46, "flown'");
l"lBe disp __ str(.rm1. 46. "Up ");
}
if (i_buff [O] & LEFTBUTTON)

/-~

test fn·r

~alid

selection t/

·{
1f{!left_b~t·ton)

/* nmst rPlease button from lest aelect 1 1·

{

Icft_bntton

ifh,abs

TRUE;

left button preos~d ~-;

251

{

mdtch(y abs)

case 8:

end ~ouRe eYample ~;

Mouse lnfornrntion · Progrnmn1.ing .Example

!0- 25

a·{ld.t·rt_;:·y
~Pt:: i ·~::.-:-~ry

'.if.J_."i;..:>£·

.. 1J•.;r~:;:1-\~l!::;

~1pz-::.::;.tf (·-~ _tpff !

di.~-P --~tr(~~(J,

3-:~ l

}

~f<~

i.:.:c~~·i'il"Xt>.!.:~;~tt
-''.'?"~:,

f:.}ci

::,

lC\r/Gd

-.r~~ct,<;f~

··/

Chapter 11
Diskette Drive Controller
Introduction
'ThP diskc:tte drive cnntroHPr
the \//\XJu<:dJ~: .svsten! bus and th{·
di.sk•,tt;c drive·<. 'l'b: cltskette dri-u·· umtruller i;upnort.s the following- drh•es ;md
rnndia;

Drive Type

1'11r~ di:>ik(:tts'. <.,l.rl'd._· r.-ont.roHet npt-"rDt~-::-1 in

eithr:·r J') ~.,'l A or cun-r tl\-f /1~ rnodf_j. h~
j)tvLl\. 1no de. the nroce~;sor iniUu_ljzes t.hr~ [H\1,.:\ ('untrnHt:'t and 1ssneS'. the
1

transfer cornrnand U} tht· dis~.::eti..e 1.'.t.H1t!"Olit1·". ~fhe disk~_:::th~~ coutroHer ~1£H-i 011--~
rL\'J_/\ rontrulko.r t.ransfet tiv-.: dHta unurtc•nc!0fL lr1 non: l)~~,JA rn'.)dt:. tlie diskett.ti
controU~~r gPner:n.es intc•rn1pts t.o the~ fH'(H~t~ss1:.:1 r

transfer-'1 :t d.~lta bvtt~·-

r:::tch tirrr(~ t!lc f'(tnt.rolh~r

Diskette Drive Controller Registers
Th•' di!':kt:tte drivr:'. crintrol.lcf lH"' five 8-bit
four port ;11.ldresse•;. T;-1bl<-: l 1 l list.s the register'>.

Addresc;

R/W

o:wzu

\·V

o:3F4H

Main status

Data
03F6H

Control Register ~03F2H)

7 ~f)

\·V

i\TOTOR B
0 ,-, Drive B motor off and disable bit 0
l ,..., Drive B motor on and emible hit 0

MOT\)H A.
0 .~ Drive A motor ofl and disable bit 0
1 ,., Drivl' A rnot•..lr on and enablF bir 0

DJVL\ ENA.BLE
0
Disable the diskette drive contrnller<e• DMA request. Dl'vl!\ <H>
knowledge. and interrupt requt>st
Enable thP diskeUe drive controllers D.MA reouesl. DMA ;.icknow\cdg;P. and interrupt request
"

HES ET
ti -

Heo,et tlw di,;;ket.te driv•! ('(mtro!!er
End1l<' th·; d.isketk drh•; omtroller

w
0

DHIVE SELECT
0 --=

SPf(.•Ct. j[)fi'F(' /\

t '"'

Selen. Driv,, B

This hit is enob!ed or disabkd

bit'> f>-'I.

JV1ain
l

RRQJJEST DATA
FOR

NON-DMA CONTROL DRrVE 31~lRIVE
BUSY
,nusy

110

LAS'~~~~ lDIR - ~---~OD~
Bio

R.i\\'

2lDlUVR
lltDRlVF. 0
BUSY
BUSY

J ---~

BUSY

0 ~~-;;
l

EST FUH MASTEH
i)at:n
noL read·\.~
l)ata
1'·
-to be read or 1-vritten by prou'ssor

DATA. l/O DIE - !Jat·n L'O Direction
0 = ·rran;;:fer dnt.(1 fron1 ,,.,.,,,,,,.o~,
J "~- ··~rranster dHta frorn

tl)

prOCt';".:iS-Of

__L

DescdpUnn

- -,-----i -- -- ---r------

r·

CONTHOL BUSY
Cord-.rqlh·;t

n .-. :':.
1 --

C1,n1trol'!e1

to :H;fT!pt rH:v,,- \~un1 ~.11.an.d

n read or vvri.te r:nn.1111;1nd

I)f.~iV'E ~! HCS~Y

0 ~
, =-

i)rive :3 not
[)dve 3 tY~~eking nevi tra.c!-::.

l)RJVF 2 BtJS'"f

JHU\T J HUS:Y

P!UV!~

n BUSY

Dnta Register (0:3F5H)
7

-r--·--·-··· · T - ~- --,-- --- -

0
-.,..-·-·-·-·

·-·J

STATUS OR DATA
-

- .J

. ~--~- _L_ ... _______ ,L __________ t_ ___ --~---L --------

i1cce0:'le:; seYerul intenwl diskette drive controHer

The
on the state nf the rli,,kPtt ,,
<:rnd the diskette drive cont.roller states are dlsi;ns';f'd
!titer in this dwpter in th;; section DiYkct.tc DrivP Colltrolllf'r Prognunm.ing.

Dislwne Drive Contn1lhcr - Ifardwnre DPscriplion

Data Transfer Rt:1te Register (O:H.-fHl)
7

--1

--r

J_ol {) .J..

B h.,
i

<.:

\ .\:

-0

\.\

THANSFf:H HATE
00 60t) l{~ Bit~; per .;.;t;conrl
01
zfiO !\Bit!' ocr second '
10

Per

sect.n1d
Not used tse!f:cr.s :.~S-0 lCBits per second}

2fd) l\Hitfl

·ri-ie inrh;__i.:;1;ry stnnd~jt·d Lr(:i.usf;-:-~c rah·-~ f~)r tt:v: bit ·value~~ Hn) is :Jou ~\.Hits
per ~5e,t;qn.d.

Change Register (08F6Hl
7

!.J,

;,'",

0
. l

STATUS

n,,

jcnANGE
0

"----

I____ 0
I

-~_______.,

CI!:\NGE STJ\TUS

Diskette Drive Controller Internal Registers
The diskette drive controller has ;<;ever<J! intenwl registers that are read or
written through the dat<1 register ris a st·ri<is of command or status bytes. The
usage of these registers is dependent ol\ the command. Tablc.'f U<.l t;hroug·h
11·l7 (h_,fine the con1mm1d specific usage.

Internal Register · Command
f

1~~1"

-r :FM -1r--:-· --i-- - --,-----~~~:AND

~ _"J

-- -

SELECT

--·-----..~ · ·-----. ·---·-----. . . . . . . ~

MT - l\:lu!ti-trnck i ~,:Lust be (I for snme con11nandsi
Disi' ble multi-track
l ~"- Enabh; nmlti-trm:k !Acn•ssing both ;:idc«> nf t.he diskeu.,,
;wtomatkallv)
..

MFM - i\lodUied Frequency l\lodnh1tkJI\
\l
Use FM o: n'quency !\'lodulatinnl for reading and writing the
diskf:ttP
UM; l\'H M tor
and •wit.ing: the di.skette
IN

SK
IJ

\!\lust be ll for snnw cornmandsi
Do not skip sectors cnntllining· a IJEU~TED DATA
ADDHESS .MARI\
.
Skip sectors contn.ining a DELl::TF:D DATA 1\PDHESS
:rvl/\HJ{
·

1.-0

COl'v1MAND SELECT
00010
Head Track
0001
00100
Drive Status
()(l]() t

\Vrite Dnta

(10 I lO -- Head l.h;t:J
Heci!ibratf~

001.l .l
0.1000

SPH'.:«o Interrupt Status

0100 l .

\Ynt<.' DPlmed Data

Ol o HI c~ Read ID
0 ! J 00 ·"'· Head Deleted D<i ta

oun.1

OJ J l l
1001)1

l 1001
l. I l 0 !.

Format Track
Seek
Scan Equal
Scan Low or Equ;;l
Scan High or Equal

Diskette Drive (\mtroller · Hardwm·c Description

11· 7

lnternal Register -

HEAD
SELECT
0

-----1~

~ i::it·~c ~- d_1, :_ ~~-"E:

fi;~-~~er:t, dt:vc l
St~10_~~'t dri~..-,~: ~

-~,,~---~J

Intern.al Register · Status Uegister 0
7________

_,,__~

--r

'
TNTERIWPT

SREK

CODE

END

NOT
READY

111EAO

UNlT- :,;!£CT .. ·1

ADDRESS

-.-.. -_J __ _

!NTEHHU PT U)DL
00
Conmiand comµ!ett:d
Ol
l'omma.nd srnrted but did uot
n
Coninwnd was never st.aned
Ahnnrnia\ tonnimifo.n lrli&k drh·B
'. l
SEE!\ END
0 CC': f>er:k
S•;':t:~k

('.heck

Et'."

errlit det:cc-ted

>.'.!

l
f..t·

ddened or, durinir a nx.Jlibr<•tE. thcJ trnd~ 0
w;~s nnt detected atter 71 step

NOT HLADY
!Jr.i \.T"' •Ni~S
J:ld'»e not.

fl -__:.:

Fault

H E\D ADD HESS
0
Side 0 ~elected
Side 1 selected

IJNlT SELECT
()0 -.

~ U

~- l

Dri "'~ 0 !il'kcted
Llrivc l. fich cted
fh:i-~J;:~ 2 SF:iect.ed

l)rh1 ~? ;5 sz;le~~ted

I t - ll

Internal Register · Status Register 1
~

1-------,--- ·

I
1..

0
MISSING

DA'l'A

OVERRUN

·-~J--~ ---~E-·RI--\.0-R
H

ADDRESS
MARR

Et-J - End. of
f)

f"~O Ct:'F}f

('ontroHer
sec"'.::nr of n

!),1;.·l-i\. E flH.!) tl
Nn etn·:r

Cn1it:r-~)1{(~r d{:::tcctL·d a

d~.e lf) or dntn

fkJd

()V.Sll.HtJ.l"-l
t_} ,_

-~:(1 .:~rrnr

During a data tr~in"ifor ln

~nt se.rvii~t:: tht~ controHt~~-· \vit:.biu the

_No ertnr
Ch'lc~ c:f t:ht:~

did

condition& otr'"'.Jrted:

executic.1!~ of ~-t rt1~1d dah.1 _ B write~dw~tehxi dat-H. or .a scan
eornr~;.;,Hu:L tht~ c•Jnrsoller c.ouirl not find th.e
.se1~tor,
ext:c~n-~on •)f a

rc:ad I.D co.rnrnancL the C(1ntnAif_:"!r could not

.IIJ field.
t')~CctHJon (if a re1:1d t.ra.ck. con1.n]and~ the starting f}ector

c.ot.dd nx1t be ff~uEd.

11- w

Hit

R/\V Description
H

NVV - Not \Vdtable

0
1 c

(Stat.us Regist<>.r l · cnnU

No error
During n write data. write-deleted duta. or format t.nwk cmnmand. thr-c cnntn1ller detected a write-protcwt signal trorn the
disk drive.

MISSING ADDRESS MAH.I'\

0
J "'

No error
One of th1J following condiUons occurred:

The controller had deux-ted the index hole twice. bnt had not
detected the lD field ADDRESS 1\.llAHK.
The controller could not ddect Uw .DATA ADDHES8 M:\HK
or the DELE,T~.:D DATA .ADDHESS MARK. \.Vhen thl'> bit
is .«ot, stattl<: register 2 hit 0 I l\HJI .i~ set.

ll- u

lnternal
l

SCAN

DATA

CONTROL f;.RIWR
HARK
JN DATA

HIT
F.QUAL

L ___ _

{J[<If'f"f~()i,
:j

rvf/'i_H.l(

CHI:LE'f·E LJ J:t_,,.\'f/\ ,:\f}[1 rtr1;ss 1\'I/\Hl( n1:ff d~::tecr•:;'{i
;,·~ rPo.d d.dta (Jr .:;(£Ht (:ornrr1ancL f...-1.~x~ ct>r1~~~oik0 t fnund a
f)/\'Tr\ /\.[H)HESS rvI/\.BI<..

<,fJ~~i;''n~i;:::r dett-:(ted t1
ttH; d!:lt~i fiefri.

nn;!'?_ber u~ -r.hl";. f_L) t.ieid df1{~s :not ru;.:trh
tht-: ~ntern.~i!

Ii.Lrt.ibt.'!' in

rhe ('Y.c :.1_.d.~c·tt nf n ~(~i.:H1 co1.:-1cn.-rn!fL th.{~
~;:,,,,r:s sa~.hd:cd

Sea~!

>Jn f:~n-~~)r

1 "::-.

th~'.:. exec·1ti:>r1 of ;,,i ~~can 1.,.·on1n<-.n1cL the cnnt.roH~:r
~-~YLt~d n1>t. f:nd n ~er.~::or on tht!
-uun: ni~~~- th~~

fJt"

Had

,'\J ::~ ,_:-:-:-·-1·0;-·

No·:;t s~~t.isti':•d

rhE:: J {) f;('~d LS FF-~J and dohs n~Jt .tnatch
:-.:v 1:1.ltcr i:i. th-e in t.t:rr:.a l

i)uring ~>Xf~_J",<Jt~nr~ ciJ <! rel.'.d cn.n1rr!.2l"~id, th<:- cr~tU:rPHcr cGu~d
not- find ~1 .l)/\T./\. .1-\ fJIJHESS !\1J\fl.!{ c•!. fJf:LE'rEJ) f.li\']'/\.
~4IJ.f)l{ESS ),.f~~\ HE.

Internal Register · Status Register 3

r:,; _~::~=·IR_""']'=~ ol~~g·.J~~sI =~~:·~~ -·7

Ri\V

Dcs!'riptimi

FAULT
0 .., No r.'rror
~ 0Diskette <lrive fault sifrnal. de!.ccred

\) H \'\' nrn; PROTECT
0 = Di1;kt·ttc not write protected
!. Diskettr,, drive 1vrit:e proreet sign:il. detected

HEADY
0 -c
1 ~:

Driv" n•.it
Dri·c(' rt';idy

THACK 0
n
HeD<l!\.Vri1·e heurls nnt ove1· i:rack 0
1 ~ H.e-~~d/V/rite .b.e-ads over tra.ck 0

nvo SIDE;
0 :c·

Di., ket.te is single sided

l "'

[)i;d·:dtc \;1 dnuhle 'itdcd

HEA.D /\DDHESS
0 ·:· Sicln 0 ~1cleded
I
Side I sek:ct8d
7-:c

i -0

U>JIT SELECT
00

l0
l. !

Drive O ~mle ..:ted
f)rh·e 1 scJect8d
Drive '.! selected

Drive :J sekcted

Internal R~~gistcr · SRT1HUT
1

-T·--~--,-~

SRT

Bit

BUT

R:\V Descl'iption
0000 =

noo; ·0010
no l. 1
=:

0 l Ot1 :::::
0l0l
0 10 ~
OUl
l·ItJ~r-

j t:

nJ~

14 DJS

1~i 111s
l ~~ n1h
1 f rn_~->
l.O rns
ilm~;

- lf'-~~tt_i 1.Tnlo<•d ..rirne

0000 '--'

1G res

0010 ~

.:1-:-~ LDS

~Hi

·J~~ ~!l~

01)01

1000
H rns
1001 ·- 7 iYl
J.010
6 n:s
l0Jl
5 rns
] ! 00 =-· 4 ms
!. HH = :J rns
l. l. 10 ~~::
'2 rn.~~
U.U = l. 1l!S

£.ti.OJ

0 i i 0 ::-:-

SO n•s
rns

::~13

000
flil.l
01n
01;
li)O
10.l
1l 0

128 rnfi
144 ms

~7;

l ll --

JGO ms
l76 .ms
1H2 tHh
208 H1S
22--1 rns
'.!40 ins

lnU~rnal

r-.

I ~D-j

ULT

. -.L ..
Bit

!Ji\\

Dc'iuiptlon

7 1

HLT · Head Load Tinw
0000000 -.
Nn hond lond d.1111::

_ _ _.1__.

UOOO(H 1 ! · 1. .l l. l 11

NJ) · Non-Dl\LA !\lode

n ·" 1li\'L\ mode enabled
I. ~

!J.M.:\ m•ltk disabled

internal Register · C
This i:Hiit rc~i.st.t.'r
tlw currently se!ef'ted cyiim!r-ritnick mnnber. To
ensure that it is ::it the corn:<.·t cvlindcr!track. the di&kel:te controHi·:r crnnp11res
th!~;
nuinUer to the cylindnr/trt1ck in the ~t:i~tor hettder.

Internal Register · H
This 8bit
th(' currently seierted reudiwritP l:mKL Tn ensun:'
sh1t li !~ ou the n1rrcrt .side uf 11.w diskette. the disJ:ette rontrnHcr i··ornpnn';;
thi~ ht_~{~<l addres8 tu tfte head 6ddress i.n the serf.or hE-"'.~1deL
0 ond 1 ;;u·f~

Internal Register

OOH
OlH
02H
iJ:1H

L!S
t:jG

0-H
(}f;f-1
OGf l

20.JS

fi] ~:

] t.L?.,~
409G

Internal Register - EOT
;_f~e ]asi" se.rt"-Jr t)r ~i tr:ad/·rvri·t.e
i:-s t.ht~ U;.;.;t de.sired sf:t:tnr

gr. "~i:~,.~tor 11, ii:~:crna~

-,.;·.:_:1nJd contain OGl--f

GPL

Internal

!o~TllBt-tt"nc~( ;:-·:}rF;:-r, :r~d i;}~(; ;;; -;_r~:_d~Jt: r.ff :-~4 li. ()t.herP/~~;~_~. u~~e d v;Hue Gi 1 lll-L
'fl·:(·;se ~~,re- :J~t.: v::i~~_ 1c~-; sptT1fi{-:'d
i:ht~ :H.():\J BHJS. Se(~ fntrrn1pt: JJil ~n

i r:J.

It{·giste1.·

.
·f ;.legister
· s
~. C

"'1

F'r:i,· the· h.1 rrn.at-~-r~:~_ck cnc1n1E:d1d. thi.'~ 8--t:-tL n,~s;,-~-st:.e!
•l:.

~lt 0 l.. ~~r;;1:.

Internal Register · D
For tlH.~ h.ln.nat .1 _n:tck C(nnrnar1d. th Ls S-bir, reidntcr
the \·aiue use.d as
rfo byte hir thi.,;
tiv; HiHvf H!OS defines iJ Vc!hl+.: ot .Hi!L SPe
J 3 t-; ~n (, t·kYpter t,
·1

Internal Register " STP
1~·~.Jr

the Si.',t;tH ccnr1nV-inds

~:his

f~!.tecc.:!t,p :H:f.t.t~r.q !!nterh.1 tfVt~ i:.rf

Rcgist1:•r · PCN

Diskette Drive ControHer Progranuning
'rhe d1·~kt::Lr'. drh;e contrcd!er hvs t.h_n::e
and result. ~rhe t~;~x::ct1t !:;tDL•~ i:-1 ·d1_:tet1nin1::d
r-.'L\. S'f".Ef{~ ~-1nd bit (:. d/() LHfO nf fbtj rnaiJ1 stiiLu.~~ rt::p·ist.er, Jf bit 7 is f:t1ual to
{). the rl.i:skf-~t.t.t: driv~~ contrnH.c~r is in Uh~ .-,.. ;.;,_!,~rut.ion strde. {)tlH:ts.\'tSt~, tht· -diskf.::'.tP-~
drivt~ cuntroEer j5 in~ c!·:;ff-.rn~Jnd 1JJ'' !e<:;;,.dt ::;b)ti;. Bil; G d<nenninc::s \;·het.hnr !'ltf~
dis~i(•t.te d_rivc: (~0:1b·,-_iilt"?f i~~ i11 drc· r.c::ffi"Hn}tnd or r~;::std!_ sUJte . i_f hit fl is f_~qu.nZ t.n
(L the di~kctt[-~ driv{·_ ~:ont~nlk:r ir.; in the 1·fJn.1n10nd state-, (Jdv~'I_--\v:se. the
0

Connnand S
1 he di:;;k.t:tte drh'f; {~~J\H::niUer i'.;1'c~·:pb:; a ~icdcs \.)f ! u·_; ~·~ con1n1~:1~1d.
1

thHt. ~·~x·.:-.:

:n Lne d:.t_t;:1
Er~t:h ;.~orn; .r1nnd h:~~~ r1 fixed ;:.;et nt d.;:~Jn by·tc~ th.nt
nrc f{·_1 Q~_r.lrr:.d to ~n.itiate th~ (·nr~nnrtn.d. ~\)r con:'ect r<::;~1.dt~, ti.1,;.; ~ct ff;u~:L n•,:i( b~
v:~·1t_1J:n

~r1u1·tencd.

(Jn rnc<:(~pti.trH~c oi g ~"orn:-1l~H~:L t.h~J d.i~k~:;ttc dd·ve c.nntr~;.il~_.,r ent-,er:q the t·~~..:t:~~u!,i,f.rr!
if
1'".(iIT:rr;-!_nd i~-; n.O\:.
as a. 'e~.;olid cnrnxn~:~.nd, th~:; dlsh:;;t.tr~ dd-vf

~tf~tt':,

'The disl~.t:(tC dri:h:" Cf!Ht!·:·.;Hcr !I~~s fift~-~-e:i u.:.nn1n~-ind.~L 'f12bit:~ ! r-2 Hr~L) ;·-.~~:'.
l''hn 1~(t!n~c;;~n(h: listed in 'I nbh~ l 1-··2 r:~re
dcE,crlbt·d .:1;~c:r it"! 7)·,1~.,

(.lI~k-c:t.b: ci h.:~~ (J);-1t-xcdir:~r c•.:in~ntind:;;_
d.t_~sc-r~t.K:d

r: tJ.~~ ~~.(::··ti~)n

("nn1n1.:ind

!)escription

Mult.i-scctur read d sectors with DXJ'A ADDHbSS
MAHE in lmndcr i!it the current track f
fvhi!th;ector write iit the current track iwrites a
DAI':\ ADDRESS l\L\RI\ in header!

vVrite Data

.Mu.lti·sf:rtor rPad 11t the current track Onduding those
wi.th a UELETED DATA ADDRESS IVIAHl\ In
hemlerl
'\lulti-sector write vt the 1.:uoent track lwrir.e;; ''
lJE.LETED DATA /\lJDHl~SS \·lAIU(i

Read Track

Heads tlw ![I fidd of the first sector enc(nmterPd at

Head !D

the f'urren\'. track

Formats scctnr:- in tlw trcick as indicated
Dnt;ci ori the dlskettf' i!i compared for eqwiiity w dnta
in memory 18-hil dntaf

Ll:1ta on the dbkette is compared for equality or a
value kss than tlw d;ita in nien1ory 18-blt ifota!
l h:<L; on Ht1' disketrv is coruparcd for r·qua!Hy or a
value grc;iter tlrnn tJw d0ta in memory m-biL dnt~d

Bt!Cnlibrate

R.ead/\Vrite heacLs n.'.tr~JCt to track 0

Sense 1.nterrupt Status

Return:; the intern.al.ly sLOred st;1.tlls
Seh t.he dbkctte cont.rnUei parameters H.EAD LOAD,
llEAD l.'NLOAD. Mld STLP HATE

Ln:.ids dv' c1unmt drive stul.us into the internal rc~;·iste1 ~ st;·~tus
t'i
-"
track

Diskette Driv•~ Controller · Hanlwure DuseripUon

i~ c~.:n~;)\~ 0... c, t.~.v:; (~_:~'kc:U.(;'
t~.lt~ p.~-~·F_:-.Bs~~~i:' ~}1~~~; ~.-'.'.Lt~:~•"s

t!tI' ~~ cr,nrr;JH~_~;- ;.~c_;-_1,::..r_;_:~~:':'. -~~::
::.ht: rcsui:, ~~L- t·~~-

i1lt~-:xr~~p~: t~;

Onfor

Registel"

Comn1ent

(~')t11rr.:·1nd

('nn1rn11nc\

I kadii ·nit 8dcct

H.
H.
N

Sf·c:t(H' nuinher

Ser.ti.Jr Size
Last sector fr.•r

EffI

l>PL
DTl.,

Stanis
Status

Sta tu"

CrliHd1:r
llead :11.ldre,,s

H
H
N

Tnh!P l l.-4

Sector number
St>ct: ,.)!' Sizt:
1

\Vrit1' Duta Command

Ordm·

Comment
\'.omrnand

Si.\ must be O

t lof~n{i/U nit St~iect

I!
H
N

Sector nurnht.:ff
SP<:tor Size

EOT

Last t>e<:tnr fm operation

GPL

(lf!P

IiTL

Uat.a Leni;;th

~t.ntus

Sta tu~~
St~ft.US

H
H
N

Sert-{Jr n.·un1be.r
Sector Size

l 1. • ?1

Tubfo l J-:)

Order
(--:j.Jn11nand

ll~"'~d/linit:

Seklct·

\ '.

H
H
N
ECYr

OPL

DTL

•--'

Result

St-'CLt:;r rnunhe.:::
Sector Size
L::1st sector fo1 >JlY,~rnt,li)rt

St·,atus

Status
St.t.1tn;i:

Table

Sector ali.t11ber

Scr-f.1.)r Si7-t"

1-G

tlcnd_;t~ni~., Sc;,le•.:-t

;l
-1

c·

H
Sectr,r :1urnbf:t'

Secttir Size

EOT

Last sectrir for- iJp..:;tat.inn

f;l 1 L·
[)TL
i:H.ht'JS

St;Jt.U~

St-Htn.;~ '"'''"'"'"''" 2

(''

Sector nun§_ber
Sc(:tnr ::;izr

Command
•)

Comnwnd
HenchUnit Sel•"n

MT mm:t be 0
Cyiindei·
Ih·;H! 11ddress
Sector number

H
H
N

Sec.tor Siz(i:

EOT
CPL

C1Hp

Lnst sector for •>pHation

PTi.
Statn~

Data
()

Statns

Status
4

Tnhh· 11-8
State
(;nmt\1and

Ilcsult

Scetcir nurnber
8e1~tor Size

Order

Command
Ht::1dil.1nit Select

l\fT and SI{ mns!. be 0

Stutus

Sta tu~
Stat·-us

H
H

S!";r:tor nurnbcr

Sector Size

DiskcUP Dri.'i!' Cnntroller · Himlwan· De<;eription

Tub!e 1 l-9

St:ts for Formal Track CornHHHJ.d

Cuni:n:H:d
2

Ik:Jd/CnJt Sett:,-!
N

Soctvr Slze

Sect<;r.s per track

(ipf.,

D
S:.:&Lus

St8tus "·'""<'",,.
'l

St.:J.t:~s Jteg·ister '2
i.·

Sector n'.in;bnr
SecuJr Bi?.:.P,

( '.ornrnttnd.

lfoadlt'nit Sde•:r
H
H.
l'-1

Sei~t.1Jr n~u_ntJt:"~r

F;ector Siz•_:"

}~(YI

LasL s(::;~_·.r.{.1f fr:r operi::lti~Jn

GPL

G:; p lenrrtJ1

~~I'P'

Intf~rfr-:a-~-·e

ot- ~!.!

Statns

addre~is

H
H

Se'-' tor n.1aY1bcr

t.Y

Sector S\i;e

Tat;!P 1 !-11

R~giste1· Sets for Senn L<.•w or E:quui Comr.na1H:\

Ordn
(~cirn~na11d

Hcad:l'nit Sdcc:t
'}
~J

C·,rlindcr
Hca.d addn>ss

(

H
R
N
i;;or

Sert.or number
Sect.or S i;·e
Last ><ector for op•.•raUon

OPL

STP
R<.:0 .,ult

f;tattis

3"'

Status
,,

lcl
f{

State

St.r1t:us

Intt~de,t~t.,;e {1 nr ;.~}
(!

.,,"

i)rder

Sector number
Sc,c.tqr S il.t..:

Cmnment
C(lmm;.rnd
.l kadiU nit Sehc>ct

c
·\

H
N
EOT
GPL,

STP

Result

~ect.01-

nun1ber

s .~r·tor Siz~11

l.,,:lst ~cctor for
len~'th
lnh~r.leave '·I c:rr 2~

Starns Begister O
S 0 Htlls Regi..,ter

Status R1C;R-isu:r ::

H
H
Nr

Sectt1r nu1r1her
Sc•ctur Sir.e:

Diskette Driv(' Controller · Jfat·•lware Description

l l . 25

Si::d".US

P( i";

C-n1u n1i-~ n<l
Sfl1~/-~-lLr~r

Sets for S(•nsp DriH• Sun.us Command

Tnbfo U-W

Order

Comment

Comnrnnd
HewJ:Unit '3dect
0

Tnhie U-17
Order

·(.'.on1r11ent.

(:on:rnand
!.kadflJnit Select
NC\J

HCS'..Jit

None

Progranu:ning Exa1nple
lnitl:..~lizing the di'Si:~e 1~te dri\,(·- t_.·onr.rolier

"
•

DMA dat.a irnnsfr'rs
the di><kette d.-lvc
;nick

CAUTION

prng-r.funtn_inf!,' or in1p.ro1Ji:.r
of thi~ dP\·'ice r~an
cause tlve V,:\Xrnate v•m!rnt;itlon tn malfunction The ~cnpe of
tJ~t)
iR En1ited tu t.he contt:Kt
this. rnariuaL No -ntl.11:~r u_se j~,. inU:nded.

Dislwtte Dl'ivc Conirnlfor · Pmgr;onming Exan1ple

JI - 27

~' .}:

!• bl.t ~~ask fnr dii;e select~;
hi~

:1:td8'.:Jn0

Df..'~='f<_:~1GTt~R

~L:

*defin~

llPVE_~nraE

0~.2c

~~lti~

~llo~B

fd~

f;o r11n

-~1

,, b:i T

-;,-

,, J·,;.e f •er sco u, i_ -t r: ::t:n i)f ~r rate
vAX;:iate 2 so Kb it 1:•rc-usf £~!' Xrjt e
J
a.tUIA f tJ t 2 f;{j Kl: .ct. trt!.nsf r -r-at ~
~ t
I ,\-;

·'

'
O·~Q~

r·rno 3eBY

'
~

sl:~" ~ r;- d.t:) If?:

bUH }' d•CJ ~ng

ci. -l ~~,~·et t-, i~ cir ! -;;
husy ri~} ; liil;
d i.,fo,K'.€;i; t e driv e ~-~ t~LL~- ',"' de 1ng
Jiokette d~j~e 3 busy dGing

i F'DDl .. E'USY

UePt

! J.~Dn~~ __ HVSY i FDD?-_RUSY
/~-

•::ont::r.:1lJ1t-: b'HS\~

e>xec;rt.if'•J: phase buey :t·/
J,j 1ntlic~tes procesgor sho11lcl read data TP& ~!
/
d?...LJ r-B-gts:tr-:1 ::;-eady tn nFnd. 01'.: xe-:..:;eive */

11 - ')~

#dx~f .i.r~+""

SfVJ_Jt~-0

#d+;:- t 1.n~ SR/:;

1 i;S

#t!ef .'in~ SRO .US?
#de:f i.t:t_~ SRO JJS'.3
~td>U f tu~ SRO __ ;-11)
#d~_d::L:'1e

SH.C .N!t

/ · at
at

t:t~1.:i::.

:1.r..it

t~-t:lr.F,t

int~.t:·.t-·.r:1pt

t.·,Lme.

u.ni_~_c

:Ze.1r--ct

~ea~

a~dr~~s

d-::._~i::ei;tl;

(ly()\i

OxlO
~def:tne

iHt.:f~rti;.p"::

-c'qu_q.Hu~nt"

~cterr11pt

time

tr(ti:--:!-: o

:~-enc·~_:;.

<-~.,-~ck ·~:e1..-nr::otu1d

SB:-J _SE

c,r;.-t .-r~a.d·;

dt: l •7e

,;:.:iuld. x:.Gt

{:!:l(·•<!'..·,

d;:.::h--~

•::.-..nap1~~t~d

#define SR(' .IC.AT
#d~f ine

SfJ) JG IC
#d.0.lii1e f:RO,,.I(!_,;'Hl

#~:J.~ii.ne

fk]fJfi'j~

Bf\1. :~A
SH i. N~J

~d~f .L:~~

SR~

;~r:-

1 ;;

i:r:.tP·_r:-upt

£.. ,__:-&~

::J. t1:~1: cupt.

;c;d~

o . :OO

'J td::{:'X:~ ;lpt

f!.-;~(1·\

-:::_:'\'.7uldn ~ -~, f i:td ~-~ectcn:·
/ }; i:!.1 d •i~.:d:
_1--;· rlflt.a fi{.;.L:i

i.>D•.i~

~r~t~:

(c;., lr!

mi~ra1ug

~l;-:-'.iJLl

pr~tect

ati~:·e~&

('{~f!;r!UJ_:'.l(i

signaJ. d~tect~d
:,:·'"".:::t·:J lD

e:r- fJ:Jul-dn •· t

C{Pl

mar~

hi.'.!-'t

~je\d

<:y].:i.·nd:e-":

fL~d

/' ::r-._it

;.~e~-~·.;1:-,

u:ni.t

F:•e1~·:·~:

/ .,,. d::_· J ;;e sig:sR,:

/ ,';_' dl''; \f{~

j~t~

b~-ld.

21~,:-,2,\

D~C~',•'J.T.

..,,/

lf.:i,;:f ir:e FOG_ fW
ttdefi.ne FDG __ RDD

Ox0c

re~cl

:#d€f ine F DG ~- ~1\)D
#tlef ±ne FT.JG RT
#dd i.ne FDC. ID
#dt:f1::1.e

FHG~FT

*~d~fine

FDC _ SE

#define FU(!

.?.DC __ SDS

L:t ac-l:·

r:i'.:~~-d

Ji:, *I

/ :~.

$('?!!.H €•1,UUl

.h-/

/i· 8Can low or equal ~
!~ acat! t1:~gh or Pqua-l ~;
!t r~ca·tibrate drive ~/
B-l?!:nee.~ iz:·t.err-u.p-t t1.tatus .,.i
/.;: sp£·Cify ~i/
,: -1, t-enH'f> dri ,:_,~fl ~twt1.t~1 ·-<-I

~·Dc __ SH~
#define FDC_Jlf:CAL
#define FDt'_SJF;

FiJr SEEK

rei! d

!• forcat t7nck •/

#-{h~f-tn'~

#defin~

data ;/
wrjte ;~atB ~;

write deleted d~ta
:' -1°

~=1 ~

#dcf~r;_r~

d~let.ed

#d?fintt FDC.J-i;)

: :-- r;·:.odJ f i ed treq:?t:~1(:y .11cdulatiou 1- /
skip dit:J.et~d da.ta n.d.<l:te2~~ ~ar1-: -1:/

,.,::~

#defi.nE RETRY __ CCtJ~T 4

;,_.

J.-8\·~Jal

ez.r-<.)7:

\.1f

i.,.,r:_i'-'l'lG'wn.

()_rJt~in

,,-/

I
/t f;i~ was exµ~~ti.ng ~ead ~0t ~13.t~ */
1~

c~-~f

tftd~f in~~

ER.f( JUT: Ar

#dEfir~

£RR_SE~K

tdc

4a3

e~pecting

.r-f (

OxffftthOGOi

write n~t read
ti.me out

! ,,. d_r i '.!€
-'~~-

11D't

rsca1.·J1-:;:tJYL~~

be~~

~rro~

:f'l->~J}f

"'f

0r-.t:or .... !
f'.'.l rc-:r

u.nwigrn~d

deer;

unslgn~<l

t~s~r-~edl;

char
cltnr
unsigned cha1
unaLgncd char

fd-::: gt_,~1t.
fdc_data:

/+ di t~kelte c~-;ntro1l~r c<n;.t,r:-ol register
/* J/O RpAre not ueed by control lex

:1nsigne<l char· repervpd2;
nnsiF;rH:~d.

diskette cont:ro 12.er ;nain ntatutl regiatex· ~!
/4 diskett~ controller data register~·

: ,_1:

J/O apace not us~d bf controlle~ ~1
d'Lskette <"ha.nge reg:iet.e-r ;~/
wrlte
-'data trao~fPr rate reg11LaE +/

BASE (FOG +)Ox03F2

I* bese nddress 01· FOG stru~ture ~-,

(:ha-r· dtr;

/* Tt:)ad -<

} ?DC;
ldofiDP

~DC

unsig'!erl r:lrn£ F:i. ·

unsigned char
~rn.!3i gn.-ed. <:bar

~fm:

un~.igned

iai..~t;_cmd;

c.hnr

~ k:

int b::s•; :,
1.-n.t I'f""t.ry:

unnign•d char deer·
nn.s:igned ct.iwt dt-r;

1nt hsd;
int ~~~d.
irrt, ~nod,

/;'· rnultJ ·i:.raclt; *
/.-i, m.frn/.fn\ ·t/
/1- ski.p J...i
last cotrJ11and sent to fd< */
/·'' buoy fl 1\g './
/;~: :retry ,..,(l'Unt +'/
}* deer rontenta v/
« v: data transt-lf::"r rat~ .1:/
I~ bead netLle delay ·t
!~

~otor

start up delay

~.·

/·~

motor off de]_ay

tg:ned cha:r dR
uradgned char c
unBigned <:har h.

drive aelect 0 - 3
/--¥.. c;y 1 inde:r nntr.b:e-::r ·-:· /
/ -··· h~;ad side

Un!~

unsigti.ed r.::.h.n'r

ll!li2::.~g.nPd

'
chn.r e.gpl.

u:ns i~ned r:ha:r fgp1
u.neigncd char SC ;
•U1$igned <:h;;r d
UJ.16 ignt?(i cha.f cit

uns±:.,,.;:n.f:d -:-.hax stp
uru; i gned ch.ar srt
on.signed -'.':ha.Y hi t
;msigned ci1a1 fl:;.-~ :
unsigr:.it:d ch,;-.J..t
J

se-<:tt:u n~. H''"-blYr .-.-/

/-·t

unsigned t:bt:1.r n
unuignod char oot

per sectors ·1·;
eud of track
!* se~tor gap length kl

by~cs

format gap

~/
~1

:,. rlata :il";ngt.h

/ ,;- scan sk"i p B'ect,rn f , ep;
atc-p rate t,:L;:ne " I
head Jo ad t:irr.e ... /
head un:L<>ad 1;im.-f'.-- )t /
non-DHA mod" '
/

/ ..

FDG GMD ;
Di<:;kctte Drive Cunrrol!ct

len~th ~;

/'f se~tor count
!* format fill byt~

Programming Ext1mple

u;\fi·igi!ed cc~.1."'_'
ur:sig·:!E'C: ·:J:.G.t'

~-·~t:JJ.
:;i~,~· ·

bJt~~

?ec
{•nd

~~J:1'!:i.fJ3~.7d

-::J!~ ..t

f~;.=l;

e~~is~~d

~~~~r

~c;

f~n_-~{11;

/ ·~'.

1'!.:-:c.2i~nt-;-j

t.t";}.c::=l-i

~- /

?:ilJ.,; J.er.. ~tn

ncct;.::1:r C'{•Unt:

s~;~~-p

N~~tcrs
iY'.f

.:::;"lt~-

t.5.m{~

head ~.0sd

ti.ia~

~;h1.r

J fD9;

·-~.n:~.i~n·::~i

•7;.h;'i ~·

·;: t~l

',~J"l..td.gtot~d

cf:a:r

:H:<f;

·~!1.;:;::_?;.::~ci

;.~::..::;

'-S:i'"TOJ';

p.i"t,'.:B2ii.t

unc - g~1~r: ~~~h~ l' ,:; 1)~.n~e:

/>1.

-::-:> :~-.:_;;·~~t~J·

~r:r-~;;::·

r~t~:1;b{'.J::

co-d,;i:;./~t"¥..t,ns

declare some Pxternal timern
1: ~.~ '';

fl'"·'.:t·Bt'n J.:nt. head_ 8e-tt] t.;t
e·)o:tern int 31otor, flag:

* *·"
l .+

hf' ad sett1e and motor startup ti1:tC!: */
:autc.matie matnr shut off timer >.-/
/

;i:.

/
;• declare space for fdc paramet•r data

FDC~CMD

frlc .. cmd

{

/:1: nnt rr:.:1.lti·-track to stat:t -->!</
.~: aJ...:ay6 ttdm ';YI

0::~00.

FDG_J•1FM

OxOO,

/ 4

O.r_OO,

not t1.kipping "'. /

no last comffiand ·yet

;·;; not bu.ay-

-·'/

fALSf,
OxOO,

}'flt

cutrent rctri.es
nothing enabled imU l fdc

OxflO .

res<>t

*.1

data transf!'r rate is SOO Kbttti .,/
19.b312 ms ~head Bettle dcla~ *!
/~. 3.90625
$
1:?8 ~ 500 ms ~otor stnrtup d~ley ~1
/* :1.90626 ms ~· b12
~ seconds mntor off delay ~;
1~ no drive selected ~,
~ c;l.inder 0 to start ~!

!IHL 500

!J.

t2B .
[11~

OxOO,
01.00 I
Ox_ Ol,

/' head zeJ<J to "tint
1· BRcto1- 1 tri etart
~.J12 byt("S p~·~r seci:{~!'i:-l */
of track at eet:trlr 16 °:

/w
~nd

O:dO.
0.db.

!• aector gap length

0"t_ fi4,
1~

format Rap J.ength

secto~R

Oxi:f

OxOO,

/ ~

OxOd,

o:-.oe.

iH3t

tfj rn8

1~ 50 m~ head load ti.m~
128 ms head unload tine
I• acle~t d~a mod• (OxOO

zkipp.i.ng

p~r

·track *;

fc~msL

fill by·~e ~1
·• datn length •/

£-~ct; ors

during ;H.:au ·; .-

1 ins iucrc~ent) OxOf = 1 n1~ I
( CY01 ~ ~ nis; 0~02
4 ms
,J~~ma
OxCl - 16 ms. Ox02
') *' ./
in

};

FDU fdd(2];
FDG_ltESlJI.T

/8
fdc_i:~sul t; •

pla~e

p1a.,·-c

t.\'t

to stoJ·e
~t-c:ri;;

disket~e parameter~

re~ult.

¥;

a.nd error- cod.cu ,,-/

motox_bff() - turn diaJ~eti~~ drive

~oturs

.. /

off

r:ot.;:n:: _off(}
{

FDC <pfdc = FDG_E/\SE;

!• ta hold CPU IF state t/

int intr._ flag~
(DRVA _MOTOR

I nRva_~mTOR);

/* both ~otors a1f ~I
1~ turn them ofi ¥!
!• nn interrupts plPBBP
t~ clear motor time? ti

outp(lpfdc->dccr, fdc_cmd.dccrl;
in1-r flag~ int off();
""1tor_fl.a11. ~ O;

/-~-

int __ on ( i.Htx .. -flag) ;

a1Jcn~..

int-:.~rr.upts

{./

~urrent

{

PUC ~ptdc ~ FDC_BARE:
int i.ntr_flag;
dn::r & DRV_SEU !
fck __ ccid.ds I;
(fdc_r:md.<h:::r !t UlRVA... MOTOlt I D!iVB MOTIJR)}

if({fdc_c~:d

())/:~

if not

all rt~_ot.>')rff< riff .ct/

{

fdc cmd.dccr &f.:i::: cr..d deer

DRV_SEL

/ '~ fie"5~ lect

d:ri \"~a */
aelnct driv~ ~!
/* beth mDtors off ~!
;~

fdf'. __ cC'ld.d'l:

fd<.:~cr:~d"d:.:-.:cr &:~

(DR.V.A_.~1UTGR

DRVB_ . MOTDR}

:if (~Ide ~rr~d. ds)

[d.c. _cn~d, dcc:r ! ~

DR-~_IA_VJJlCfi.;

slae fdc_ccd.d~cr

DRVB_MOTDR:
~r~t~

!*
1;:..·
r:~ot0r

___ f1?ig

-'.'lf:

the register

Er.e:r-r-1Jpt!.1 ydeatH·! ~/
c]~ar ~~t~~

ti.meI t/

J.nt _(fl1(in.t::r

head settle timer to ~ime ~tax~ ~p
/~"'- w~-i.:i.·~, nJ•::i.t~-1 motcrt is :..t.p ·~s 2pt:-~d ·</

nn
\CCi tf'

the

ili~e~.rupta p1~ase

~=t~t.o:r

::.-ff de'lr~:l ti~b'

ai~.n~

int~z-~upt~

!• fdc_in() - read data from fdc data register

•I

j¥~*~**k*t***~'+Tt~~-·~~~*~·~~~~~*~~*~~k~~t{~~·*l~t*·~~0~~

~·~*Bi-~~~~~~·+~:•/

fdc-_.LnO
{

f'DC "phk
-1.nt i;

3.9 ms, muat read in 2 cycJ.as ~!

h·ead_set:tle
i

inp(kpfdc·>fd<:_stat);

ft tjme out error 1 ~;

if ( 'h<'lad_settl<i')
{

fdc ___ rcsuli .. ertor

read fdc etatua register */

/* fd~: ready '} -!-/

while { ! ( i & RQM))

ERR.Tfl;

I e:t.ttl'fl;

inp(&:p1dc->fd~ .at..il!tl;
else i
}
l f (i &'. !lIO_RD)

return(inp(&pfdc->fdc_data)):
else fdc_reault.error
ERR_FAT_RD:

;~ data direction ~ cpu read 1

•!

-; return data read •/

• mark fatal error •/

Diskette Ddv<: Controlh:r · Frogi·urnm\ng Exmnp!.e

fd~._out()

-·

~rit~

data t.o ±de

d~ta 1eglst~t

{

FDC •pfdc v FDC_DASE.
int i;

inp

9 c1s1 ~u~t read in 2 (Veles
i:{ .r(~atl :fdc stat.us ·t.:e.gtrd·;.er ...:/

->fdc __ stat};

whi1e( 1 (j lrFJ,JM))
{

fdc"_re1~11]t.f'.'1:.ror

1 ·'"· i. rfr:

o::.

x <'.'ad•/ ?

F:RR~_Tfl;

return;
~lsc

iap(kpfd~

~fdc

atat.}:

}

jf ({i k Dit1_RD) ~= C}
uut,p{Atpfd::-··)ftl•-= ,daT,4.

.~data

;.ra1~te) ·

else fdr_r~g~lt;.~rror = FRR_.FAT_WR·

{
{

chk_dt(};

~tr~~~iOD

~pu

3.tc id•- tl4tB
j~ •

":.a.1.k

•

~Tite

r~~j.a~P:r

fat..tJ~

e::ru:i

j
·*.<

if(fdc_.reault.error) return;
switd1Chk .c!"d. l<wt;_.-:md)

error " >'/

discover last comma.nd iasu<'d. -;/

{

I• recalibrate ? ~!
/.., seek 'f :•:1

head nett lt:

fdc.cmd h"'d:
wh1le(head .. settln)
fdc.c~d

laot_cmd ~ PDC_SIS,

fdc outfFDC_SIS),
:if (hie. Jesult. error) r"'tuni:
iac_reault stO ~ fdc in(l;

if(fdc_result error) yet.urn:
fdc.result pen• fdc_in() ·
if (fdc __ ·ref.n~tt. _~:irrffr) r·etur:n;

set bead settle delay timer •/
! •' wait for h<>ad
/:1-

B<'lt tl<>

to time out ~ /

aet last command iat:Hl.,ed ,.;
eene.e "interrupt status _,;,:/
_

error 7 -i"/
/i H!ad ritO results "/
/* error '? .~,/
/ .~ read present. cylinder number :;../
/Jt er:r<n ? J-/
!*

b:tea."i{;

commands except F!lC_SPR, FDC srn. and FDC.SDS :-f:/
/:+ read stO results -~1
fdc. in(l;
if(fdc _.rrnu1lt,"er:r0r) rr•ttt:rn;
!* t1::t:t'OT '.' r/
id~~result.stl r {de in():
/"' read etl rem.:lts ,.,;
/-i;_ error 7 ~1
if(fdc_rP&ult.error) return:
fdc ceault st2 ~ fdc_in():
TPa.d fft:/. results i:/
/-,, error ? ·.;,/
if(fd~_rBeult.error) return;
'

det :a ult /-' a1 l

othE~T

fdc_:reeult atO

tdc .. reault c ~ fd~ .in();
Lf(fdt;_result error) rat.urn;
fdc.reault.h = fdc._in();
if(fdc_result.errar) return.

fdc.xee.u.H. r ~ tdc_) n O:
if(fdc_result.error) return;
fdc_result n = fdc. in();
if (fdc .:n.~snl't>. error) return:
b1 ea;;;

/* read

~:y linder.:·

re:~u1

-t-/

error ? 'f./
/t: read hend reeuits .,,_;
/* e::rror ? *-/
/* .i:ead sector result.e -~I
/t. error ? *l
it .r"ad
nrnults
l~

l *-

€t':J'."OI

~:I

}

Dif'ker.te Drive Controller · Progrmmning: Example

.l ! - 37

/* specify() -

s~t

the diskette drj.v~

chara~~er1stics

Sp&::~(: "l f y ()

{

FDC "'pfcic ;:-- FDO_~BASf;
char uc:

!t temporary

unsign~d

/-~

<mtp(.!tpfdc-:'dt:r. fdccmd dtd;

erro~)

r·~t~~I•i

uc I: fdc_cmd.bnt:

/:1-. issue att<p :rat~

fdc __ out{uc),
if(fdc_,_re.::.n1lt,~1.-rc1.)
u~

I~ ftlc_~cmd.nd

fd~_c~d.hi~

td.(: __ cut {u.c:) •

ratf?i ·" /

ucL cantrul ~egi_ster ~;
.1·+~ lat\t ~:-.:1;rum0ru:i ie. npecjf·;,- ·;r,/
/*: iHSU~ specify- co:runa.nd ,.,._/
/+- -e:ti:-or ? -~ f
I• specify ntep rat~ ~·;
1-~ sp~cify head u11load ti~e *I

out(FDC_SPE).

lf(fdc_result

t:ran~~ftir

->dcrz Id~_~md.dccrJ;
:fi:ic _cmd. _la st_cimi -~ FDC .. BPE;
fd~

µet d.at.a

vori~blc

~nd

1.H::a.d unload tj_me -:"
/¥ f7rrcr? -''t
;w SJie~ify head load ~ime

rvt':._uv

t' sp<edf-; dmi'.i mode •i
/A

J s;:n.:.t; head

Loi1,d -t. i m~ al'.:uJ dm:."l :r.>:__)o:'iie

/* fdc. issueO -

rrnue all fdc command~1 e.xcept, spec:lfy and si.H

/.r-: des:t1.r::"!-d command 4·/
/• deRlred drive 0 nr
~1

3nt cnH.:i ~
int dr~
{

fDC •pfdc

FDC BASE,

dHn: o l uw [ 20) ;
drv;

!• indicate the drive ~!
eelact appropriate drivo •/

fdc_out(FDC_SDS);

-., se:tHH~ d·rive status "'-/

f1:k. <'md .ds

('H~iect(cJrv·)':

/·Af error ...( ..,.,._;

if(fdc_reault.er1~r)

return;
fdc_out((fdc. cmd.h << 2)
fdc_emtl.de);
if(fdc_xeault error) return,
id~_xesult st3 ~ fdc_i_n();
if(fdc_result.error) return;
sprintf(l'line. ''7,04x %04x". pJ<k, &pfdc·>dtr)
disp_str(16: 1., oline);
fdc r~n,..ult.chang~!
inp(&-.pfdc-·>dt.r)

07:50:

/-"'·

(;'"t't::Ol:'

o:,./

/• read atJ result• •/
/ -~· er:r:cr '? ·;. /

read disk change r~g •/
/ -~ d:r l ~:e ready ? ;!·-/

if(fdc_result.ot3 k 6R3_RDr)
f<lc_<:rr,d. las1. •. cm1d

* second byte 01: SOS ~1

;• set last command Laaued •

cmd;

ff~it•ch{cmd)

{

case FlJC_SDS
:return;
t~rt?a.f:;

ca Be

FDC_FmGAL.

fdc4_out (cmd),

if(fdc_result error)
fdc_out(fdc .cmd ria):

r:etUl'D

/* recali_brate 7 ~:;
,
": /
/' insue byte
,.,.
-t./
+ error
1~

lBAUe b;t-e 2 Bj

/ ·'

j SSlHZ

/:f:

<>xror 7
iRsne byte 2

ti-~:eaJ~~:

Cit${~

td<. QUt (cir,d) ;

if (hk.remd t. <"rror) return
fdc.J~nt;( (fdc_ctr,d.h <<_ 2) ! fde;;_ r,::~1d.ds);

tflfdc_result error) return.
:!'de

/...,__ s~ek

F,'PG_SEEK'

'lut,(fdc_,~md.cl ·

l:n:. t~a.t'::

byte

-_;,

,.i

-::-/

; ol'

l ~-1-;

I
;::/

eTrOT 7

I " iiume byte 3 ;, i

Diskette Drh-e ControH01· , l'rogrumrning E:unuplc

i c~:d);

i.f(fdc_re9!ll~.P~ror)

~etuT·n

fdc_{Jut({id~

c~d-~

/ <t-'

<< 1;

ID
bytt:

~r:rn:r

1: e~.o

fdc_nnt(fd·:._'\~:md.:-:dm

SU4'1

/ :.$ :lti t-tU.€' byt~ 2

•

"'
'~

;
t

t:IBDk;

fd.r out(i~:h· .,.C'1F:.fllri1

if (ftlc_,·e2Lll~

cc~~~·

e~rnr)

~~~~i11-

1·ac .. -.D~.It"' (id:~ ·~("!~:d 1;. '-.< 2)
if(Jdc_re8uJt.~~1·~r)
:~<j(C

C'J~.\J':h

.~,,r;

fdc .. c:mti d.fl):

:i.3SU't

r2tt~~~;

;,·

fdC .3JUf:. (.fd~~:.~ . ': jit)., 3~:) ~

if (fd::":_r~~-ult

{n··.".'(fl·)

if'tt:rn;

tivr~tc ·;

/x -et:t-_,1"' 7 +"/
iSSi,.;"';~ tyt ~· 3 -~ /
i ,:,- -.i::r r;;r ·t -,;. /
1~sue byte 4 ~/
/* error

·fdc_o:1t(fdc_c~d.±gpJ):
i!(fcl~

testil.t.0rrcx1

fd('_t:>uJ_-(fd~:_e:~.rnrl

re~.urn;

,'.(::

i i ~.!-:-ch:_ 1e.;-•-:.J;_t .e::':'~z.:x)

idBU~

°*/

~Y:!'Ot

hyte 6

~:/

!:~-:_,J1~;:i;

1~ read data ? ~;
/* read deleted data ?
!* write dsta 1 ~1

-:" o ~~ >?. ¥ OC _.\-<f.UD-:
fdr_out(fd~ -~~d-~~

fd~_t:~ci.~~m
-~-~·~.ue

if(f0c_·t~:::---;;,lT~
fd.-~_Qt)

p~·:n:~.r)

.tc;-:_.'J.In~

tf~:h:_~;:'.:flld_,_;j ~

j-f(fc.-:: .. lBSU.i.+: i?r.r:0.r)

brte 2

-er:tor ? -.../
i9HUe b)te 3 ~!
j ..:._ B-l:t·cr ? Z'/

i ~

iFn-_~lJ.~)

~.-~t'-~'!"-~1:..

fde, o~_;t(±i:L: ... c:::_d-h·.;:
~t.r~?:r,)

1-'2:tu-;-~~

.fdc _o ..:;t(:fd;_-_- .c11d .r) _
il:(td.-:. Tf'.'~:~1-t -~:r.ccr)

"~ f (fdc._rebU.i_t

:r~~~J:tn;

byt.B

-lo/

/ '" ": 'f'rru1

-7

""' /

~.3n1_;\;;;

1€'.·-.,,.;lt ~i- ...- ; : ; )

r£~:vrn.

fdc,cn' \fd.: __ ,>;,,:_,(~t;]);

? ·-~ /
B -;< /
/
?'
9 '/

:::dc"_0tJ."!:. (fd(: __ :_~nd.
._: i :h1::--

·~·~y te

Example

nrne FDC .RT.
tC"'.; cut (fdc_ err.cl mf!:t ! 'fd?: ,t+md, sk ! c::1_d),,
if(fclc_r~sult errt>r) retur11
fdt: __ out. ( ('fdr: --~:rnd. b << 2) ~ fdc. crnd, dH.)
if(fdc ___ reEult.error) retn1n.

a track
byte

r ~«ad

/'-i!

JESUI?

issue byt1? ?. ··;
/~~- e:-r1:-:ir ? '!-/
/* issu.e byte 3 ~,
/--~- errnY' ? :;;.:
icr.u.e byte t:;,, ;i.· I
!' er-ror

fdc_aut(tdr_cmd.c);
ifUdc. __ r;,sult ernn) return;
fdc_nut(fdc_cmd.b);
if (fdc_result.er·ror) ret11rn:

fdc_out(fdc_cmd.1):
if(1d(:_re511]t erroY} ceturn:

f-~

issu~

bvt1~~

/""' e:rrur

fdc_mit(Jdc_c:md n):

>:--

i.ssu~

fdc .out(fdc_c~d.ogpl):
if(fdc __ reuult.crror) return:

byt.e . .,

iBf1.U.e

/ ~'

e.r:r-cr) rcd.n:·cn;

t
;

if(fdc __ .resulL.crrt>r) return:
fdc out(fdc cmd.ect),
i_f (Jth~ ___ r:e;;~t~l t

~~-

'?
byte 8
error ?'

-PY.T'O:t

-~· /
·.f. /

~-/

fdt:_ont(fdc_cmd.dtl} ~
breai':;

cas"-~

FDC _SHE:
caae FDC _SU•.·
Jdc_~cutffdc_c.md.t\t

!JC(!))

I :fdc_.rmd.rnfnt

lf{fdc_.result.error) retu1n;
tdc_out((fdc_cmd.h << 2)
if(fdc __ reMult err11r) return;
fdc_out(fdc c~d c),

~/ "· scan equal ·1·
'!
high or equal ? ~;_/

/ ' scan: loi..,1 or equaJ

I .tdc __ crnd>sk

lss~ie

I :<'.

e rrr:r
i 8Sl.le b_yte 3
;

; ,,_;

r~turn;

fdc_out(fdc_rn.ci. r);
J:f (Jdc ... J"tH=niJ.·t, e.r:r;)rj return:

fd:r_outlfdc_cmd n);
:.f(fd<;_:r.,sult.t,rnn·) r«turn:

fdc_out(fdc_cmd eot),
if(fdc_resu]_t.crror} return;
fdc_out(fctccind.Rgpl} ·

if(fdc_result.error) xetuxu~
fdc_out(fdc_cmd.tttp),

byU:

byt;~

,.. _/
/'

error '?

i B-sn.e

-.-

! ~;

if (-fdc _r:e~ul t <error} rr-t.ui:'n;

fdc.out(fdc_cmd.h):
if Utk . rom11t ernn)

•-;;.

i cmd.} _:/·,-: byt~:! t

:;• J

"k
,;,

.';

'
;

'
/
* ier:rr1r 7 /
,. is au~,
bV te 5 "i;/
'
i ,, l"l"r'!Y ., "'.~ /
,,,. iB~lH? byte B ,/
i
f
er rn:r· -r -1,/
;./;_

.;,~

itH.rue bjitE· 7
,+
/ ' t:·rro:-c
''
r.m.ine byte 8 ''c/
?
·• f
.f'~·ror
/
.;:~

. -!: i."su.e byte 9

}

Diskette Drive Crmtrolkr - Programming Example

ll. - 41

{

dx·ive not r-eady

~iror

}

~ni_t

f f>r ccrnmand coMplPte ~;
/t. die.play 1:·esHlt ;;Jtatu3 ·--:.·

}

~l!itialJ.ze

~iok~tte

~cntroller

-k /

/
fdz- ~Jni.t()
{

~n;.tpf&pfclc-->dc-.cr

fdc_.,,cnd.dc,-;·r:

".<~

)Mh __ "!.t·iT_~_[;f--,).

D~·lA,,_ Jr-:T-.ON

ogit~(&ptrl~--:d~~r.

~d~

: J?D( ... Li::

r&eet the Irle

c~~.d~~c)

/-·

alJot-:

~''

fdc not r~Bet •I
o::-.:::rn.mnni('~ti.n:nfJ

}

r~st~rc

cutp(&pfdc
.1!1Hi sk ( !J.

t),

>d~cl.

diak~tt~

controller

a~tl

iz1tPrrupt

VPct~r

0 -~

.1~ ...

d:;.u~hle

T'JG -Lnp11t,

,i,/

/-4· fd,.: nnt :r.i;;:t;.t>.t
cutr·\&r-f~:k: <~.-; "J".~

j_-1,r ___ L"t:-Ut (G.":(=e}.

all.rJw c;ommlini~ati_one ~1

fdc_int. _trnnd()

·fdc interrupt handler

fdc _Htt l1an'H l
{
1~

HLSE;

fdc_cr..d. busy
enl \0);

no longer b11sy

fdc menu

fd;:: C)
{

fttatk MESH,11,GE mfdc [J
{
{
3 2'l "Diskette Gontrollet fY.ample" }
'
(
s :~-7 "Fl. Tnrn d:ri.v~ A motor vnl! } '
{ 6 ')_'( HF2
Turn <h 1.Vir! fl motor off" }
.l
{
' 1 F3
2'f
ll.eca1ibra.te" }
{
8 ?.7 ''F4
Se~~: tr<l.t;l:.- -40H }
i1-p5
g
~-~'i
{
F0rr.at d.u.1kette'' }
'
{ ,lf) ?.1
"F6.
Read TDf' }
12 2? ''FiO R~tur::n t.Q Ma. tn menu:ll }
.[
n
0 }
0
}

I• to hold CMOS byte read r

ur:rnigner! <hat tir.p;
u:nei.gned char

to h.old calculated choe-:t::!ntm */

ffllm;

dvu- line[Eil2];
-thar •-)lir1e rs1:r1.
int i
.1 t1t

to hold input Jina x/
+./

~ t::) hold output line
;~

to hold meru1 selection
/;•

"· ;

FUC_IlASE::
cha::: '°PC
<:h!<r f a.r "'·!pc ~ ollt1e;
fpt:;
Tong 1 = (I
.i IYng l 1

!'DC 'P1'<k

long 12
pr ;
int pa;

i.:1.t

~dtl'i i.ni:~

GOL 1. 7

Dislwtte Driv<:· Controller - Prog.rammlng

temp v:.?..lU.lf'"

:-r/

dl sp_menu {nrf.d·~= f :
= 1 l 0~0000f·ffl;
12
'•> Hi'
12 .:,: ~ .,,
]1

_...,,.. hu'lld. ndd:tl!f'BS

o~~

dis.p.1ay· :.hf'! frlt !ll~nu.
for DM~\ control ter

-~/

buf"f·-e1~

,l - 14 ~ l, '
11
:•> ti';
~,,

Uut) 11,

l. t Ox0000ffff;
{~_nt/1.1;

~1H!-::-J.fy~),

J.:ine[(;} = Q:

whi.l.&;; Cl)

~nrever

(see Fi0)

<lJap ~tat1Js(ifdr __ ieeutt, &fdc_cmd):
d~splay TAGUlt a~~t~s +/
l~n~[C] ~ get. ±key()~
~ get a tunction key for ~~ou a~l.e~tion ~:

t<lc_ia~~e{FDC.hECAi~.

O)~

~rlc_ls~ue(fUQ_REGAl.,

OJ~

fd.;_·issue(FDC __ SE~K) 01
0)

fd~. :~u~ue(FOG_!J,

l.l · 44

ha~d forma~

a diskettP ·-

iuterl~a~~ ~

adect.(O)

fdc

iBBUe

FDC_RECAL, 0);

fdr: . imm" FDC,RECAL, Ol;

fdc_iosuc FOG.ID, 0);
O; i

fcn:(J

;: 80; l++)

{

f de , cm<l _c:

i ;

fdc ieeue(FDC_SEEK, O);
tdc:_cmd b ~ Cl;

/.;.

~ide

>.:/

oJj ne;

pr:

r < 16; r--1·,.)

fo:r-(r
J

" +pc-"

(char) l;

·t

·-f:pc+-----::-

>\ooo~~

''p;·

(ch1n)r,
'\(J02 ~ ;

?·:-pc+-1

}
~

(int) (l >> 1.6);

d:la_tr.an.nfer(2 pr par
fdc IBHUP(Pnc_ri, O);

fdc crr:d h
j ~

"T~c .__,._

ooj 3);
/

/·• a<;tup DMil
f OJ_·tr<i'i. t 1: Ul ck:

1.;

't'

< i 6 ~ !:+ t)

+·pr_·r •

(rh:n:) ;
'\001 -

-.;:pc;+,

\CO:!~;

build sector tal1le i/

}

(iut) (J. >> 16);

daa .transfer(2, pr, pa, 60
fd~ lGeue(FDC~FT, 0):

t1 e t·up f):-!;t.._
/-i- for.r.:.at t.r'1<::~.

:~·. /

b:te.:!.1':".

! 'j

2el1-~ct. (0)
Fnc~.Rf(.f'J.,I

•J);

:!:de _iss';;.B f[H. ~~)~.Ef!AL,
.

id·~;

0);

S8'J.e

fd(~n.i8~Q~

FUG_ lD

O);

f d-c:,

~~-:::fl. !~.

-fd~·

..iB:~tI>:"(FD~:" S~EK, 0):

0----

i.1

4.G

return ta cnllex· {main menu)

~ 1

disp_atatus(prPs. pcmd)

diAplay

FJlC_H.ESULT +pre,;;
Jll)CT_CMll 'P"'lld;
{

c:hax oline[50J;
spr:Lnt.f(oltne ''E:rro:c statuB,
disp_st1(19.
J, aline);
sprintf(oline, "Status reg 0
disp_atr(20. l, olinP);
1

Ox%04x 11 ~

pres->~r~or};

sprinti (olin(~, "St,at11s ::reg
1, o1ine),

Ox:71i0?.:>: 11 1 ptt-~~i·<?-st.l-);

sprintf(oli111;;~

Ox%.02>~ 11 ,

diap_str(22

~~statu-s r~g 2
1~

sprintf(oljn~

oline);

''Stat:us reg 3

disp_stt'{23_.

Ox%02x" 1 , prep->st3);

'l. oline)-

aprintf(oline, "P1eaent Cyl Num· Ox%02x",
disp_str(24. 1. ol.ineJ,
aprlntf(uliue,

"CbanRP ~eg

dia~Btr(t9

4l. oline);
sprintf (o}j rt(<, "CyJ inder

djsp_str(20. 41. oline):
sprintf(oline. "Head (1-l)
disp __ ,utr (2J_; 4 l olJne) i
BprjntHo1.inr., "Secto1 (R);

0:<~,02x". pres-:>r) ·
disp _Ptr(22, 41, ol1ne),
aprintf(oline ''Sec~OT~ p~r track (N): 0~%02x 1 :. pie5·->n);
1

oJjn~};

disp_Bt.1'{22· 1 41

"Lagt cnmmaud '. o~.:- 11/ri04x:· 1 , pcmri >"hH~t ..J·;n<l)

t.-tpt·:Lntf'(ol:lnt~
djap~R~r(24 1

oline) ~

Atft1,11s

Chapter 12
llard Disk Drive Controller
Introduction
t ht:· ~'VOrk ~~t~.rd.on
fe;·lbJ~T~
,·-1.

Af·;-t);i' (hi~f.l J-Y:t~J1. nna ~1.r~:. g-bit

.EC(: •.:...-.1rrc:r:tit:.;.n

llard l)isk ControUer R.egisters
~tahiS

H"-:~Cf'HlO:::t;·y

infrn n.L1_Uon ... fhe~~f;
i/(J ~:H:Jdrt~~~se.~"- 'T~1bic 11- ~

PdmMy
Addre,;;s
<llFOU

iJJFlH
OlFlH

O!F2H
O1 F:1 H

ouqn

C•.ff5H
OJFt_JH

:\<lrlress
Vi701I
Ol71H
Oi'l!H

Ot72_H

on::n-1

Ol74J-i
0 'J :JH
~)l 76J~

!)iF7H

(J _,_ 7 71-i_

OJF7tI
0~·1 -Ffl l-i

OJ'77H

O~! F~J f. l
u:~FiH

0;17Gtl
O~J-77l-1

r>
"'

H.
IV\V
B/\V
H:\V
JV\V
HJ\V

Err-nt H.(~gif;t~:.:r

Sect\tr (::::runt
8ccJ-l'.if f"'hn:Jber
('.viindet Nuinber
(~_yEndr~r l"4t1rn}Jer
SLH·t {st·~cb:::r :s17.~?, rln$1e. and herH.:-0

Dat.a Register (01FOH/0170H)
15

DATA REGISTRR - HIGH BYTE

., .. c·-1
8

_____ .-.-L._ .... _1 ______ _L ___ --- __ J__

I!
B\t

DATA REGIS'rRR

H./\\'

The datH

LOY BYTF.

Dc<;er!pt.iou

provid1~s a

Hi-bit daw path to the sector buffer. This regist.cr

during· exx~cution nf f1 reiJ<l or v~T.itf 1• c-ornrnan.d.,

fur the four ECC

ot a re11d

('(llnrn;:md,

an data

trnnsh::.r!,, ar~~ .~ G-hit trn.nsfer.~

the d:1t;1 ol a 1.c.J.d Joni~ or write long t:.ornmnnd. the four
transferred one hytc <tt a time. The ECC
are Lrmwfern~d
byte The hard disk <:ouhollt>r requires a minirmrn.1 of 2 MS
bet.weer: ECC bytf' transfors. To transfer an ECC
tlw rl8ta request i[lRQl
sr:nus bit istntus
bit :.\1 1.miSt. he set. Tlw stat.us
i;, defined latPr
in thfr,;;

Hanl D.isk Driv!Y Co11tr11l!er · Hardware Description

lOLF1
!

r_,

·--· __ j ___

-· ........ L

Error Regiister (OlF'Uf;(H 71H}
6
]!---~--

!BAD

ID
NOT

HCC

\BI.OCK
jDE.'l'RCT

ERROH

. -r·
'1

COMMf,Ni) ERROR

DRTECT

-·· L--···· _

I ABORTED! TPJ\CK 0 OAM

·-···r- -----r--·

!N.o.T.
!FOUND

.-L·----·---·.!

No error
block rnark_

~;;

ECC EHHOH
No c1rnr
_;\_n 'ECC

D
"~

-t

IU NOT FOi. ND
J\l'·--~~ [;rror

0
'!

l..

=rt-H! li..::1.rd di:.;k. =-;r)irtrfJHe:
hc2d1 sector, <)r -~ize

-':°E:i.k, nt· .an !f) flrdd
.,

.'\BORTbD co:vftl.!!\ND !H~J'CC1
O c. No iorror
'rhe h~;:ird di::.. k c~Jnt.ruUet ahortt,.:~d a cnn:"ln1;~nd
If a cni"r~n1rtnd i~_; is(,ued \.vhHe the ~tat~J~:~
is \nan,ive nr th; stf.•tu:~
\VHJTG I':\

iJHT\TE tlE1\£)Y L1,
LT L is <:»:tive, the

hnrd rlisk ~--'.~_·,intr-:",dler st~t~

I ·.: _

"'fhr; bard rUsk tontrolh;:' cxerutr::d H r-c~tc•n;_'. ci:,nnnuuHL ls'.';ut:.d
204 7 ~h:;p
,-:i:ncJ did nt,,1T. dct·.(:f';t tr;.\t,J: 0.

11.'\M f\()f FU\:ND - Ur1ia ,\ddress ;VI.ark '.'l>Jt, Fc•Un(i
0
;~ l) ercfJf
fhc h;~rd cH~.k er,E1frcUi:~;~ read the· cntTt'Ct ~cctoc f} fhJ(L but
it tJ.id not: c~JHtJ.in ;:~_ d~:La ad.dr('-SS tnHrk.
0

r (ff the

;\tter a
(b:t 0.1
On p•.iwcr~up or
con.1nHtnd.,, th.e hard di!.;k c<nttrf•l!f~f
{Jn cornpMet~on nf t_.ho-:;~). t-c:st:~, t'he lu~xd
exe~-~-ut~s a set; of
rli~k !~untroHer pL:H'.CS a r1;s~Jlt- cudt: in this
ohe of the cndt·s li~ted in 'rablt~ .12~2, fo!~
t.l'.i: e~~ro~~ hit (t)I~.- 0} is

04H
t)fiH

Sector Count Register HHF2H:Ol 72H)
0

7
SECTOR coum·

Rl'vV

~I hf•: sccttJr coant fqr an

oper:Jtion

A valc1e of 00l1 indirates n ~~Gfi ~P-ctor tr.1nsfer,

Fnr· d rt~nd. '1-vritc. ur re1-:id
C()HHn.anrt this
sectors tri:1n~ferrr:d_ For t,hc; tnrrnat. cou1rnand~ this
nc1rntK'!' cif sF~!.ctnr~t tt) forn1,at IJuri.ng ri
~ect.<H
secfJH" is rr:i.nsforred or fnnnattHl, Uw hard <li'lk c<mtroller dw:rements the
°'e(·r.ur count

Sector Number RcgistN ~Ol.F8Hl0173Hl
7

:?.

- y - · · -·~··-,_------~--·_,-·· --- ----,-- - -- "-·-1-·---- ·-· ·T-·---- - -

·1

SEG'fOR NUMBER
____ J ........--.--L·--··· ·-· L _____. _____ L ··--· ~ .J___

Bil..

R:W

-~---L-_. ____ J

De~cript.inn

tirst si::·_('U_ir of nn (iperati.orL

tiw
sector t_1perat.ion,, nttr~r f'.Hcb sefj~or

i.s trtu1f}fcrrc::d tff ft1rrn<1tt~~cL the hnrd disk contrnhcr htcrernent:::. the sector
~1-U r~~l:c~:r.

12- 7

Cylinder Number
5

'''•"' ~'i-,,~-·~~

CYUNOP.R NOM.BEH
(LOY .BYTE)
c _________

J_ ~~----~- - --·~-~ -. -

nurnb.::r

75H}

Cy Ender

CYLrnmm NUMBER!
BTI'E)
!

..u.. ,......... ,.... .. ........-1___
B;,

R/l'V

Hard Disk Drive ControU•.'r

l'!Hrdw;,1re

SDH Register (01FBH/Ol7HH>
3

r·--.
RCC
SELECT

HEAP Sl\Lf',C'f'

DATA

SJZH

!I,

-L~----

Hi\V

t•:cc SELECT
LCC uH,d tfl check the rbw f.i<:ld of'' sect.or \HO!\f !:HOS
ECCi

HJ\V

;;

Hf\V DATA SlZF:

0
record~,

i."i··ead

record.s
4

H/\V

f)HJVI~ SELt:c~-r

fi.~rd cH~k~ th.·~'/(~ 0 sclt_:et.cd

l i21rd disk drive 1 selected

The
bit :1 of

value in bits :5.() 'i':'ii"cts th.•c.

tickL the FNAfH. . E>HE

the harG disk re~ri~tr 1Ti rr1ust
and bit,~ 2~0 hav(; a t~11.gt~ of

head. To DS»
.;{ !hit :1 uf

1 ()tber..,vise. bit J I- i- ~n.eff~3cti\:(:·

H.nrd Disk Drive Controller · H!•r<lwan;

(OlF7Hi01
0

reg-Ist('L \Vht-?fi. ~.!--:~?: l'•.;1.:-'"d. disk: c~"JEt.roP.er def.e·ct.s g ·co~n.nH:n1ct (zr ro.r {'.(~flf11tion. -:h~-~
b;:~_::d dfr;~-;: f-0~1t~·oder :·tb~.>rt~~ th;- ~_;on\1T:_gr;;d ;-::nd z.;fts th~; /·\F,-()R.T-F]J) C~()fii!I\.tt\N[)

\-V H.l'l lJ: i~'/\ Lf L,I' is r1<.t~.\:E:'.
f)Fti\-'E FiE,'\I)-'"-/ ;,~ i.~-1<;-~~:tiv·-s

sr:.FJ( ('{.)f-l!JPLL·rr_; ~..s :ne. (.t]vf~
(~,~:111c1s;~od f'.(_~d.c V/a-:; ~~;_·_..~~lid

s~_::~~k
~
·!)

12 . Jli

H.(~[.:(. ~~~>~'c:·H~

vv ;-it,r; s~~~:~~))t
f(;nr»1L ·rr,'ck
He: d V•cc·ify

Restore- ('mnn1and
l
~---,r-·

6
- ..

~
~I

···-----····

HE STORE COM.MA.ND
0

STRP R/J.TF

RESTOHf'; C01\'ll\1AND
STi<;p RATE
0000
'.l ~•. 0 ;is
uuo j -=· O,;J. rn.s
00.lO
LO ms
00 l l :::. .l .{; n!'i
0100""' 2,0 nts
010 I. .c:c 2.~) n1s
O!Hi"' :to n1s
01 l l ~= :~, ;~} rns

0001.•
1000 =1001 ~

4.0 ms

10\.0

5.0 n1s
t'- 0- rrt.s

1011
11.0U
t l Ol ""~
J .'. 11J 'c

4~ f~ n1~

n.o rns
o.~)

n1s

;J,~~ flS

Ull = lG.O_us

lJntli ~1 terrnin.:n.inrr c(1nd_it:-ion occur~·;~ d1c hard disk controUcr tssues
tel' th

1::

select.c.d drivf'!_, ·11H:-

.
Sll\T!'Ssful

t.n:Aler sets
'"

from tbP drin• becomes active, whir:h indkates a
of Uw cnmman<L ln this rBse. the ho.rd disk con·
CO.MPLETE istaal'• regwter tii.t 4! w 1

The hard disk o .mtr•>lkr is<.mes '.:'(lrt 7 -otep
·rlC\CE n ERROR \f•nm·
bit :\L
bPcnrnes in:Jctive, vrhi(:.h cunst:;;s nn

"
"

conditions are'

DETf;CT h:rror

Tho? \NfUTE FA1)LT
COl\'lM/,NP DETECT

\Vhik '' ;·;:store 1.coinmand is in
the ~~t~_~p rnte.

ua~ driv~~~ tontroLs

h\t ZI

bcw.otni:f, 0r:tlv1:. ',vhich <'.HH~es an AHOHTE:D
bit ~'.i.,

the !'EEK CO!vlPLETE
from
a--0 St:-~t t.be irnplied set~l{ -S:tcp r.ate. ()n

b~n-nirtath•n uf this cnrnrnund1 thP h:'.":rd <Jisk cont.roHer g't::nerat<~h

n_n intf!rrupt tn

SE-RK

t ___?____

~- -------- -------- _(

01 l .1)

:) .. ~-~

STEP fi . ;\'"fF

: i •GO

onr~J ~:

~1 ~--Lo L'~~

._::::

U,[--: rn.2

(){~~n =:

] 1-:~ rz·i~

•y;_ {~()
~-; 1 (; -~

:) {'! ffiS
'5 ff~f?

'. i l i $
1
l ,, ! i -

DOO.~

- i 00

1
:;

)

dl.ct~t(~~~ ~-1 ~:t~J~:.-~c.::s~·~Jl

;n !

~ 0
J 0

'Th~c \VB_rrE

F'.-\'UL/r

C:(}~V1fv~-/1J..~~) ~)L-'_!~_Ct :--~-

Lt- ll

0 ~l'" ;-.;;

1 [J ~rs

,- u jJ:';~i
:} ~';

rn~~

:'l~.S

6 ;--:. r~.1 ::;
:·~ ··:

:,•

fnJin the dr·i·,,,--e Ln_)e. d1Yi<~-H ;-H~ti\'€, \vhi~:~~ Jn°'
of tb,c.~ -~_;_Hnrn~l::::L Jn th.!$ c;~~i~;. th_f: ha.rd
~.:It 4-' tn

(h:s:~~ rent.:··,).\;~" ~Pt::~

<i.ctiv~~- tvb;"~h \::a~1s1-:N.

t.i!f: 2~

...

r1_n i\ J3(JI{1'l:=:J)

0
____ .....L. - ·······~-

RE/:~~.J t,r~~rc~

/:..fter tn· n;.;fp:·dr1ff: f1 s~~ctn~·- c'ff df~Ls tbJ;c h~~rd d.i~d1:: t,:n~:tr."Jlk;_r
(hit.H fi:.::Id T:;:;('C, 1f f>Otn:J(ta~:di:;
;_:_:rr<ff (!C.('nrs. the: h,.::u.·d t.Hsl< cor;t:rt).~.h.~t ~:;(~i:~! f~{)ll H E(:'TE:l)
f:~-"!k·ul:~u};-: ~1H.± rhr,eks tht-~

u'!_t~~

bL!f<l di:::t~-'~ ::~qnt.i·oH<:·]- <;t~tB F(~( E'nJU.)R, ~fiTOr
t-_-~it Of. H f::-~ ·u~·1crff:n2 1:~:; ~b!.e
..

r~ F~T·-r{f LS

i)JS/\ t~r __ ,i:-

_B,,~trV:~ f _ '..r~J~bh.;f.i

~ l ;~ ~·.r ;r~ s

o r~·Y.d
~ir·F.:t fir:(i

cL,':'.kt.b h::-d

~~;:~~·-ro:' fr .. }ff1 "·h·.:- b~:;rd ;Ji.qf:, :·h';.~- hf~.c~J di:~:~: ':'.'::rirn!!er
t-L-;-; -~<"Ct··H', ·rn i'.iri.d the cccr.--e::t ;,c~tt·,.~· the h~1~~~-~ .-{i:':!k c~:'?n

l.:!.

{f ten·f,~;:, nre enabicd and the ht.ud thsk (~t'.~nLr-oHer falls to read
~,,~did HJ fie!d i}-.'ithiE Lt·=c attcrnpts. t!u:•. hard disk ~:nutrnHer
n:~t fnlto·~--t.,,r-~t: and an ~ato-sc;~)n. ~l the b.it.rd di;k :·::nntro!~er
n::ad a '/t.-tlid. fL~ field i.vithin dri <~dditirn1al r.(~n atJeH•pts, the h;,_1d
disk corlt.rrdlf:~r ~ets lf.J .\.ot .Fn!.ind ferrCIY
bit -4·1 :utd 8.i-tR{JR
~.s.tat_JJ:--; ;:-eujs!-.=t:i

l f)

~Jct

bit 0!

I\nJ.:-1d lt:·rrsn,

bit ~.H. f\_~:':!G, t.hc hard

the bard disk cnnt.r'l.J]k~r sets
4J find t~Rt1(ifi {status
fl'E'tf(:r1n ;-:tn o.ut.o-seek

:fhc reud :1t>~tor Cl:1n:x1and t.ransft:rs the
~ek:·i::-ted dri've it the,. bcBds are not
trnUer pt:~rf:)~_~rns in irnp!i€:1i sPek t.o the pcoptT c,yiin!~cr, 'fh.0 :srep r.:1t~~ nsed i~
tbnt ._;f thP. rnost recenUy e:<<~cut.r;d r(•sto.n.'' qr sieck cf.'•rtunar::t:L fv1uttipte ~e(.J.or
~·cc.~ds t'flll crns.:.:. ht\fn::l :.Ln(j l_~,·~d.inder lX. HHHt'ir~,es. lf t.be rH·lJ\Tf; JlF./LDY

,,.\fhe-:J f:ri.clr ~:f:ct 0 .~:- i~<:< :(it:Ored in th·t f~~~'l:tor bufft~c ;:~nd ti::;~~id.Y tfJ: he re-ad
t~v:
c:pt_1, tb.e h,1t(1 d~~k -~~(_H1trnHer ?t~ner-!:tte;.; on int~;ri'npt; ff·q_:_H~st: t:::r.1 the (Pl}. ~r:t(~

Write Sedor Command
7

i--·

T --- - -- I

L_ 0

_,,,

j w_rr£

T/RJTJ;; SECTOR co11MAND

0 ___ J_ __ 1

_! ___

-r--------1

------ , -~,--- ---- -~' --- ~ -

o____J

_J~ON~~ __

RF.TRIES
IJISAlH.E

\VHJTE SECTOR C01VUV1l\ND
\VHITE LONU

0 --~

The hard disk controlk)i- caku!ate~ the d.::i.t11 hdd I:~CC ~md ,o;ppend:; the EC:C to llle data field
rbe hard disk c.ontrolkff doeN not calcu};Jte th~: ~JatD fltdd
ECC. /\ft.er
a senor nl d<Jti1, thr; hard disk •:ontro'.fidd F:CC b; tes_ The four ECC
are t.rLn1sferred une at a tJrne in the 1;iu:-h
nt thP, V•·(ird ~:;iz:ot~
data register_ Uni.ii DRQ istatl.ls
L n;J
FCC bvte is not
for transfer
E:CC bytt· t.rnnsfor$
7

HETHIES lJ!SA,BLE
0 c"- Retries em1bled
1 ::;_:::
R,etries di:~~Jbl.ed

·re, \>;;rite a Sf;.ctor frorn the t1Jrd disk. the l1atd r-!i~k (·nnt.roHet -~~-.nJ~;t
first find i he st:·ctnr. To find the r:onect sector, chc he:rd disk ('.(lD'
trnller se!ect.s the tndicaf.f:d head"~vait:s -f1,Jr the inde;r.: ouisr~.

(Jn

disk controller bcgir;s sc;muing the track for
/>,_ valid sector IO fleid contains the cvlindcr_ head. sector nurnbec
and size infonnatiun that. the hard disk cnnt.miler is
for,
The hard disk <:onu:oller ctHmts each index
'JS iin attempt h•
read a vaii.d sec1_1x lD.
if rer.ries are enabled_ .:u1d the hurd d-isk cont,roiler fails to read o_
"·iBlid !I) field \-\'it:hiH tf'ft atte1npt.s~ the hard tH"if( :,~:nnt,n)Uer
an auto--s:eek and mi crnto--snm.- [f the harrl disk c«rntrniler foi!s rn

read H valid Ill field within 3ll additkm::ii ten
disk cnntrnller ;.et« i.D Not Found forror

U1t• hard
4¥ and EHROH

2- lf)

v,·1Lfi

!T.' flt;l~::.l ·;,-,,-iLhin t,.:;'n

If) I•Jnt F'u!.:;:;d l~--~r:r~·n

in.

<·:~~<:.

~/H:' ~-.{1r~-~ tf;.~_~:-< ,->_;r_:_t~_-;f.re:' :;{;::;$

~ ::·:?!.d EH.~1(-_!f-~ ~-:~L:-trtis

tJv·· i1~··1~·~:i d;~;;,-_ r:_·1;1L-·G1!(~~- c~)(~S 1:0~· ~-~ :r~:-;r:-j·- ,::i~l -<':.t1t-u-s~ (·-)" -:Jr

::~·ti d~:~-~)~~c~:_r-

._~.,rr!te s.e: ;'~-Gr (~·:~rn.Eit_~_;·:d hd~: \('('·~·1 i.::.'7i~.H~d.
t~;c (~~~t,a

;rn
bnff·_ _':r {;{·::·.;rili/r trn<) ..~;;~.a~ .~s

·_rbe ~H:i.·,.·:. d'is;.._ ~'.or;.t,~,1~ifr~1 !~;f!i_·;~. 1·~'---:~-· gr:p_(;~·;;H:fc
ct~rnrn_h.1 td

Format. Track Conunmi<f
l
l

l
l
iI.

r-·

1''0RMAT TRACK COMMAND

l
0
1
. L .. _. -· __L ___ ··- ---.l ---·-·

1. .• ··--·~! -- ~ __L __

De,,criplion
FfHHvlAT TRACK C01\·il\1AND (Always OHll!;O()(ll

r.h1t11 from the inwrna,l rt·g·1.stl'fs and the secto.r lmffoc the format tnick
trnrk at: tht\
cvHnrler and f.1ead iocation.

co!Tn1u-n~d fun.nat~~ B

Bdore
a harct dislc the SDH
must he i.nw:ied and a restore
conmrnnd m•n<t bt: i:oMH>d. ;\&suining- that a S•:•ries of
format t.nick
cornrn.an:ds .:s.re 1~s1H:d· to h.>rHHH; th_e herd disk,

(Hl8 re$t-ore cornrriEHtd

l'3

requin+d. F·rinr to· t ar.h {orrnnt trBck CJH'nrn1:u1(L the ~ect.fn· count r~~gister rnust
1

he lntHlcd \\'ith tbE:~ nnrnber -nf sect.ors per track ;ind tl-H~

h(': 1oui:Jed "\-id1 the
fn~t~~~ad

n1.u~1L

~1qir1_b(.lf.

nnrrr1ai n:·nd/v "°ritt· drita. tht" sr~ct{1r buffer
1

1'\l~o-_ th~-~

.s-n1'~tn1

nf t!T!s S(~ctor hetH:.if!r l.ntorn:ation
~ipt-.:c.iflfls r.he ~lectcw intcdJ:~£:\'('. 'Luhk::- 12-~.-~ lists th.e d~ita \i_n t11c•nJ.ury order} thnt
l'.i
for nn interlc~n...oc fBck;r flf :~- 'fb-e dat;_1 txnn~fr;r
this table i.s
tht~ OOl--i ~n(111naJ block
!nad-·.? :,vith Gl:.n 801-i' H.1ild blor:k rnad~~ rhe ::;crtor irlterh:0\e t.HblP ~s i,<,~adcd intn
tJw· sect.ur buffc~-- in the .sarne rn:.u1Uf't a,~; .a :,;,..f.-~ctor ivriJe. ~rhnt ~s. the f(lr1nnt
bcad(·r infr.irn:Dtfr°.Hl

bu ~fr~r to z1:.~t~o," ~.ind i~":;Uf\S -~~ cnrnrnand
fnrrn:.~t tn\ck con1.rci:1:.nd~ the St:Ti.or buffet r:nu.st_. be _r_·eio;1ded.

St~ctor

Nutnbc·r
fffigh Byte/

non

0 ll-1

02H

O.\H

041{
li>1H

OJ~ll

08H
0;\ll
O(~!J_

OEH
JOH
l2H
HU

!6H
lRH
JAH
l r:I--J
1EfI
'.l.!JH

0211

0:1H
OU!
i/tH
O[Hf

nc:l-t
OEH
OGI I
OfH
07 f-i
lOH

OHf-{
l !H

OUH

SiHf:US HlllH "" Gnod. 80H ·--~ HHd1
lLnw Byr.ei

001!
OOH
OOH
OOH
O\.iH
HOH
UOH
OOH
OOH
OOH
00.f-i
!.H~H

OOH
OOH
OOH
0011
OOfl

FTH

V.FH

_F"f'lJ

fTH
FFH
FFl--!

FFf·!
FFH
FVH

Read Verify Command
l

r-·---- -,- i

I
L

____ __J

,-:~::~lFY C~~:.:--,-

-1~~~:~;~1

.__ ! ___L ___0 - _L_ -~l- J _ _0 _ .. L __ _r:_~I ___ ~ ___L ··--- __ j
__

READ VEHIFY COMf\fAND
n

-- ·.

0 l 00000!

RETHlES DISABLE
0 = Het:ries erwblr:d
I. --

Retries disah!ed

To read a. '.><'Ctm from t!w twrd disk. the iwrd disk controller mu;;t
first find rhe sector. Tu tind the 1'tHTcct. sector. the hard dbk con
trnller select'\ r.he indicated head, performs any implfod seek, and
wafrs for the inrlex pulse, On refx:ipr. of th1" index pulse. UH• hard
rHsk 1:omrol!cr begins scanning tbc track for u valid sector lD field.
A valid S1c:ctm· Ill field contain:-. the C\ Enrk·r head, sector number.
and si:LC information tilat. Uw hHrd di~;k <:ont.rrJlh·r is searching for
~rhe hard disk controller cnunt~ each index pul.~a~ l:l~ an attf-:rnpt to
rnnd i\ wdid secto~ ru
!f n~triet, are enabled and the h;;rd cli<-.k cnntrol!er tails to read a
valid ID fieid within ten 1.lit\•rnpts, the bani disk controJh:r performs

nn <Juto··seek and an a11to .~can. lf the hard disk cnntru!Ier fails t.o
read a valid fD field with.in an additional ten nttcmpts, the hard
dli~k <·ontroller 1;ds ID Not Found terror
bit ·!\ and E:HROH
(starns
bh: 0).

If retries Hre di~<~L]:k~d and t.hr- hard d.i.~k contrnHer f;:~Hs to read it
vt.:.iHd if) field \.\,'ithln tv"\I'!'.) al.tc~rnpts, the hard dist controilc r sets
ff1 '-Jot Found i0n-01
bit ·P and EltROH 1siatns ,...,,·,.«·1«· 1·
bit 0), /\isn . t.h.e hard
~~ontroHer does not uerfor rn an Hnto~,.,i~ek
1

bt;(:.()r1·i.~.:,:.:; inaett\-'f-::. or the \Vll C'l'.E· Fi\
L»r
beton1e5 nct-i-vr:. the hard di0i:'- c;.'t•ntro!_ter ten··nin.~~~.;~'.i- t.ht; ~;ornu1and vnd ~. ,F{.,

1:;

1.2 - 1!:~

t\P~\)H]'Ef)

(;()fv1I\l:\J'.'-Jl) J)E'fEC~l ~';;f!~ur ref.d:1U..'.'l hit :~) -nnd L-I~Jl(l-ll (s:t;:jt:us

bi.~- 0}.

1.2 - 20

Diagnose Command
6

---,.

COMMAND

__ L_____

Dl/'iGN!JSE l:OMll:J/\NI>

-~-------

HlAGNOSH
....L

7-0

---,---

--, - --

_.. L _____ . _____L __ _

1uu .t ooon i

On n~u,ipt. of this cominand. tfw bani disk enntrnller t'xecutes a set uf di<lW
nost3c T:e!Stt~. Tl a problein exists, the ht1.rd dish: controHrn' report.i:.; the resutts in
th•~ n-ror
\see Table 12-P. Th·~ inttTnc:d HO.l\-L intern11I HAT'vl. ETC cirp;:1tJ!: circutti·y are te-sted, \\'ltf~tl th1~;
t.Psts 1.~(1rnplcte,
th0 hard disk conu·ol.ler loa.ds the ;ippropriat•: rode Into the error
. Tn
inHlc;·tte curnrunnd
t;hp htJrd cH~h con!:.roller (_s·cnerateti an lntern1pt
reqtw "'= t n th\:' \' P [T.
cornrn~uu~L thP code· in

Lht.:; error

thrln uonn:tl error

I.1:!and result cndes.

\VDl O l ;);Wl);:'.(l](! contniller ernH

coin-

SRT PARAMRTRRS COMMAND
0

l_ ---- - ~---1--~·~ -

·;o

0
__ ___j_ --- --<>- _J

SET PAHAl\LETERS COMlvU\ND

'Thi,s C(Jn1n1and st-:ts the dt:h'e p~~raH1ete10 hn thf; nu:iy__irnurn nutnbt:r rJf hendn
~n1d ~H.:C:.tt)Y:::O per t.r~-1t_:k F;;rior to
t.hl::-: 1~(JOHn.(n1d. ~-1"~~'.'. d:dve ~'-~k:edon tnust
br:: s-pec~_fier~ h~ tbP Sector Size/fJrh·'C: 8(:~·ecL'l{e;1d Sr:!ect task
. and tJ1c,
(tndtlple ?.t·ctor {Jp~~-utions ~:.n-~
-·ru indic~J.te cornr:n.and
ht;rrd d~sk ,_'.o:nxoi_ie.t
~H; int·~-rrupt req:_tC$t: tft tb.t:~ (:f1 {J,

'fl

the

Status Register (01F7H/Ol77H)

.lr-.Bl.!SY

D~:~E-rl· ·v:~T·~··1~·::.~· -·-1· .DRQ

RF.AD1 . FAULT

·------ ___J___
Bi!

Ri\V

INDEX

ERROR

STATUS

·- ·--·- ...

Description

BUSY
0 -

}ford disk ;;omro!ler is ready to accept eomman<ls. The
status and error registers contain valid data.
Hmd disk controller is
The error
invaUd data Only this Btatn;;
bit

This hit nrnt't be polled before reading any
DlUVE HE!\DY
Drive is not

Head. write, and st:ek rornrnands are

inhibitec<L

fl rive ii, re11dv. H bit ·!
<.:omm:mds ,J;.~, possihle.

L retHl write, nnd seek

WHITL FAL'LT
O :..:·

No crrr;r

Jmprnper opernt;ion of the drive. All commnnds wiH b1'
tennin<•t<•d with ;m aborted <'(nnnwnd error.

SEEh STATUS · Senk Complete
O = S•X'k
dirert or irnpliecL is incomplete.
l ""' S<'ek opernUon is •.'ornplete !read/write heads are in po11itlonl.
.R

DHQ

Uat;J

0
l ""'

Do not reml. or write the sector huffor
Read or writi~ th;.i sector butter as indicated by tho klst
C,f)nl1T1and. lRSUC'd,

CD · C•irreded Datr:•

n -=

No <~rror

The S<cctor rn£cid from the ddve resiilter! in a correctable ECC
error. Corrc•ctable errors do not •·ausi" multiple ;;ectnr
trHnsfers t.rl te:n:ninatr:.

Hard Disk Odvu Conl.roller · IfonlwnrP Description

12 23

:··~r;_d ;~::t c\;t.t::cted

te{2
L,ilF((.JU
u

!'I:-~ e·:'.'~'f.Y"

/\. .:~.0•1n;~~G\,-':'..;n:~~:il:.; Br!<~r f1?.B r;:~_('.i_~.rrf:(L
t~i~ns th~-:

2.rror :~t.:;n·-~_u:

bit:.. Ii U·;.::=: f'"'~~;-,_} rE:.;:;k ;~~«_ :n!.f't'~Ecr ~(·t~ ~,Li.~; bit
tr~·:E.~fe.}:-. ~.hf;; b:-;;:1.~:,;~·cr ];:; ~·cr-r:tiii~7.re~l

-rl·;e ~~n·r.-~r l'f.:_!{;"iStf~_;· (':f.~~:

Alternate StHtus Regist:er (O::tF6lJ!0;>,7()fU

Bard Disk Registe1· (0:3F6H:037filU

ENABLE lUAO SELECT BlT ::!
H.cch.H·;r:d ;vdt.t: turrcn.t enat)i~;d

HFSFT
1~/Vhen

thf.; hnrd disk controtic~r enters th~~ rt':,t::t- sb1to .::-tn-d.
qn~.n. thi-~ b!~ is <:.~e;'.lrt'~.L ~i 'hi? ~Jit n1u_r~t stay" SHt
tf;r ;;1 nununurn cit b J.-iS, \\- he.n U1t~:: Int 1s 1_·-~earetl tta:~ h:xra

~f;tnnins. .

tJ St~t (n:

tJ'~~ts

I.t-rrrtfYr E\LABLF. Interrupt En;:,lbie
fLu·d dL:s.k cnrlixuUer
bufff:T i:s ennblierL
bit d.ot:s not f k~.1r the h<~td
cfJnt.n)Her int.t~rrtt~1t. output_
\·\iheo thls hit _!s cicnred. anv pend1.ng
·A.·HI n.:Y-ur
Hr1rd d~sk f'{n1i.r0Her
bnffer Ls

o ~

'fllis b!t: 1~:.:1al:-lt~s nr dis<.i.bh.~s a buffer bet. 1;\'t.~(:n t.he hard fU:-;k c(nJtnJl
ttT

ou.t.put anrl th+~

cnntn)!Ier :,-~µuL

(0~lF7H:0377HJ

Digital Input:

HKAD

HEAD

SEUX:T

SELECT

SIGNAL

SlGNAL
0
-- ·-

--~-------

is acti-'\~e_

i.s ~:l::f.(ti_ve

2 t~ act!v~~),
2 i~ :n~J.rth:..:'._

n
i

.H.(·~ad sei~:·ct

-.-

i:c; 'K!-.ivP
i::;. \.rH~r.ti.ve.

J-I~·an selcc,t,

l{ L/;_ I) SI:·~l~ rA···-r Sl () 1\1.A i {f
tr
~-I.E::~H} ~-elc!:.t
0 J~ ~-1C!)\-~t:.
Ii<::B':'.:}_ t11-cl~~ct
0 iB ina_{',tive,
l

fJRI«:,_tr,~-.

,_.

SEi .• f»Cl~r SI(, %J}\L i

f)r~ ~c'f: fA;k--;ct

1. is {_-.;_ctl_·'i-'"~"

oanm

DRIVR

SELECT

SF.LECT

SIGNAL

Programrning
Exa1nple
~.

•

lnitializirg the hard disk controller
Ilt«:alibrnring the hw·d disk drin;
a hard disk

CAC'flON
Im1.1niper prng-rarnming or improper operetion d this dev.•ce c<m
crHJse thf~ \!_;,\):,'_1n11te \.Vorh.st;1tion to rnatfunct.icnL 'The scope of
the programming example i;; lirnit.1.;d ro the (OnLcd
ia
t.h_it:; ru~n1nnL No t:ithxH~ ;..1&11;~ ls intcndrd

t2 - 2?

C·.r-4.G

and 3.. lt~rn~t~

adrlr8~s

/·,J,

~-:EC/

~nultl :J~~

d~git~J.

.EGG

{;-:[r~::i:r

~tat!la

r1!gis~~1

i.nput

teg~flte=

·;,_,

di"!.t:i

?0(~tq ~0r=P~t

_[9

·f:'te~.::

~...--/

!iel~

1./

#defiue STAT_BSY

Ox30

#define STAT_RDY

O.x40

#defi.n~

ilddinB SfAT_\.IF
STt\ f SC

(J-<20
OxlO

#define STAT_DRQ

O.x08

#dt?f i ne STAT DU~
#de:hw' STAT ERR

0.>04

OYJ!l

#def Loe SR :3bU8

0:\00

#defin<> S!t 0 SMS

0Jd)l

itdefixw !ill 1 OM:;
#defj.n~ SK l. 5~8
#d~t tne SR 2 Ot"iS

Ox02

#defjne SR __ 3 .. 0MS
#defjne SR_3_SMS
#define SR_1 _OMS
*dt:-'f in~ Slt_·.t _Sf-1~8
#ttefin~

S OMS

hdc bu!'!y

drdy pin -t./
1~ write fault ~/
/_,_ seek' (:omplet0 -.i-/
/~-

!• data reque&t •/
data was <:orrocted
I~ nonrecovArable er~or l/
1~

!~ step rate ~ 3h ua *I
/* step rate
0 6 ma ~;
/* ~1cp ret.e
1.0 ms *!
!~ etAp rate
5 ma */
step rate
2.0 me •/
1~ step rate ~ 2.5 ms +/
I• atep rate ~ 3.0 ma

<h03

OxOl,

(V06
Ox07'
Q;d).]

/ -t step rate
/ ,; step :rate

o·,.-09
0-<0a:

ntep :tate

O:-~.Ot-1

#~efine

SR_6_b~S

#'.def 1 :~.e SR __ ~.:;

atep :rate

i:r..

3tep rate

/ :.- st'.:.'P 1.-at-e

:·us

ildefj ne SR _l _ 61J8

O;,:Of

#de-f J nB Cit:D _I~

0:,"·08

#def :in~~ GMD _MS.F

(J'irO;l

#det ilH~ G'MD JJ'il

/ i

11t.n-p ·rat-e
step .t:a te

l .6 HB

interrupi; ~ontrol ~1
sector 11ag ~1·

~11ltiple

trde-f i ne CMD_RE.fil
(t~~n __ Sf<Er:

0}.1 ~)

ifth:f .i.:'.Vj

0·-!_7(\

GMD _REAi}
#detlne C.91D __ 1..JHI.TF.
#defin~ CM) SCAN

O.x?.O

0-icJO
(j:-._110

c;(t _FR~·!AT

(Jy50

~lde f ::i.~1"'~

3.2 \l(l

/-k lG:n.p; rr:ode Tt'ad and ~rite
dieab1e re1,ries

tfd£:f i,~:te GMii_ TPY

#<l~f .~_1.1~

4.0 ::ia
-4. 5 .ms -!:-/
5 0 ms
s, 5 In$ ·+ /
6, tJ ma . . . ,;
6 5 ms :-1< /

/:;;.;
/

\>,'.t J t ..f!.

cotm!::Dilil -,. /

cormn.and.

furmat

·t= /

~ommand

com1t~nrl

O:dJ1

see~ command */
read com~and ~!

''f

)j<~

"'- /

/w set parameter command

.Ex.mnple

12 2n

lH18 ign12d

.-,:;;,;:1 !:

t:;.~c: _.t~L~:f'.;

UtH3 i~n-ed

chH~

~ ! :t -· Wj)f~ ;

/'"~

se~ tor buf_lfc·x

J'.:"f:~i

or:/

(R)
;~

t:;_neigned cha::t

(R.li·!J

(WJ

f'.Ci'OT

wri~P pr~~onjpensatio~ ~yl~nder

4 /

(f\/h1) Reci~Ol' C(tt:.. f!'t) -t'/
! ;f
(.R./H) ?-e-ct01, :r;o.umb'1i1:t'
/""· CR1W) l!:-~,,~-r 8 hit:~ of \:-;1in14?'.r 111_rn:bF>r ,_,.,
/'f-' (tiJ'i.J) :.t;:.Jpe-x , ,_ _~ bitP Df ;,-.;'l i.ttdi::~r _ttHrnl:-e:r ..g_./
.i:;.:

:_;<

uns1.gnerl ch~l gn;

unBignec cn~r ~vl .lDw:
unsign~d

char ~Yl hi"
eha:r sdh;
11nfiJ.gned r]1ar c~r;
nus1sn-~d

t:.dh :r-egt!<~t.~~:r

(R/W)

fR)

J-'itaLu~

-r-~!~.

~,/

(W) C:C:"':;mar:d. rr-~g; -1</

} HOC;

int-

r~-··r-

J~!·~~~ry

a.l&ctndte

L~Re

address

r·y _

u.nrdg~t>d

j_Jlt

~ontrol]~x

reR

/.,.: bui::ty f1a.g •·/
+: .-r·r:t-:.~v con.nt i/
c y l t~1de-r nu.mt'l'f: ~ 1-:. /
0

cyJ:

·ci.he:ignP-1

ch~x

:.iu:.~t ___,":--nd

u~eign~J

cha!

Rr~·

i :-:<
!*

la~1.

~ea~

to !:d(·

sectc.t

n~~her

C'U'~

~:n,.-:::~7.

c~mmantl

una 1 gr1e~~ cl:;o;, :.:· rh.: :
:.~nsign'0D

o-.:.ha.-r~ !t~"

u~slgncd

c~ur

s~;

un£~i gn<E-d ~b.0.r

d!l;

f0r~a~:

/ ~
tP'"t·~:tg_TE;"d

;:h.JiX 3-h

\.:l'<G ~.sn:~C. <::Hit:"

} F'DC ,., CMC•

f";f

g~p

lAttgth
mod" ··-'

ri<>E <WA

typedef

ut:tu·~ t

{
!~

~yJj11der

unnigncd int cc;
•~nstgned in\. wpc;

w1·it~ preca~penaation

unni.gned int h<'
in-t spt;

count ~/
cylinder */

/+· h.ead c.oun.t *. /

Hn1Ji.gn~.:d

Rectors

p~r

track

} HDD;

/-L cyltnde-r numb~~J ·T'/

an£-l'lgnetl irrt c;l;
unG-j gn-ed

f~ha1

~1·xor

f;r:r-ox:,

unsJ ~nt~d cha:-"

cnde/atat11s

11nsigned chars~:
rir1.

unsigned ~ba~· edh:
u1toigned char stat1~s;

sector count i·/
Hf-ctn r- nnrnbe r
·!:
s:dh reg1Rter ·1:/
~t~.tus registc1 k/

} !!DC" R.f.SIJl.T ~

de~·lare

npacP for hdc

para~ete.r

data

HDD hdctt2J
:: 6 i 5

' t~· j s

30·)
300

.,4

l 7
'!
17 }

,-r.Hn:T..a.ncl da.ta "'

result data

/·.., hd.,·: I./!J bu. fte-r

~. /

-~' I

12 -

')3,~. i, . .J1dt. ( .1

{

/+-

bGn.\c

bii_. r;htn..t1d.

ifCi.n?f,'2".phct< ;~~~8r} &. STAT. _ t:HRJ.
hdc._cesu}.t.0rr0r
inµ(&phdc-~err .wpcJ:
~ise htlc_rPsu1.t.~r10~ = 0:

wai.t
bB

un~il

interr1Jpt o(·::ura

c1r:ar, but Just tn

Ct\BC,

jf e1·ror condition *;
x·nad urror regist~r ~1
1~ mark no error ~!

{STAT~Rr~

I STAI SC))

S'f!~.i.-_SC))

}

hcc_.t~suJt.status

r~ad

ft3L11s

tl.i$plai

rt~fH.t

r~gio~~r

:":<t<jt~~-S

;c·/

HDC ,;·phdc

hdi:: ,,c-:r::_d tn's'"';;

<~h~r Z}lj.n~[2D];

{

:' :~- !°'il."a.d.

UJ ? .. /

P-1'.:an ld c 'Jr:::!1:land

~'"°'" CMfi ftFl\O
a,$1_~

c:1D

~!R

ITF.

re.t:id d.ata ?

i_,.;x-i t-€ dnttl

}

/-i~:n;.t-,p ( &:phd<:: - >c ~' 1. ~,1..;;,.; ,

:_.,-T:- :1 ;:-ie

.hd~:: "" ~-- r:ld. ~: y l J ;

,:!utp(&phdf.: ·>c·~J., hi~ hdt.: ,c~fad cyl >;. 8);
hds (} ~

t· ti~:- Beet ~~r r.\.'_::.rr.be-r
~Tit~

s~ lee~.

~s·ite

bits

2 hi~h b1.tA

lo~

:--2ppL 0pr ia-t~

wri. tr~ tJ:e

d.:r i Yf<;.

~- /

{';-::mun~n-:.d

12-- ;n

·~

h.dc ~- :i Ii-~ 1. ()

1~~ .inl~.(Ox7fl)

iniL:ial:iz~

the interrupt
.. ,

hJ~ ~0t

zeu~t

~.na.b}r-

aijd a.t.tow

PJC

~Pt:to~

jn}'~lt.

-~'/

iEter~upt

}

/ .•: hJ ·: _ 1.- er: t ( )

hdc __ rest ( J
{
;~

i·,; __ reout(0:.:.76·;;
-:~utp(tiilH_ J.:SlL

;

dieah:!

tcstt:-1.-t_'- th{:-

hJ.c ;:~Gt

rvF.et J:IJ:1~.1

PlC input

·lr·.~-~~rrwp·1;

vc-ci_.~r

t Lr:.i\.J

J.t:t.e·-~.-z-111.rt

controll~.r

rcgia~era

{
l~DG

'phci:"

pclntur t·o

:+. /

_,..

hd.c(}

"xei:ul.e hard disk ~ontroJler exa~plea

{

f_
{

2T
27
2?"

"llllrd Disl" Controller Ex.amp.ti:• J-.
11

Fl.

Re::.:al1hrat1::1! }.

'2"!

:,:·r

1-~ 1

}

2'!

'"F5

Seek_ - 'i

}

{ to
{ t 1
{ l2

:rr

"F6.

R>cad UY' },

r.?T

""F7
~t Purnat DjRk ~~ (Erases data)• },
"FlO. Return t~ Main menu" },

{

'' } .
. "F3.
''F4.
St-et
H~'1Hl

(; },

};
d1<1.r Enelfil?,].
char oll;w [512}:
unsjgned int cyl,
un.signed 'int ht;.~hd,
HDfJ *' phdr..: ;
i.nt ··Fi,
-:tnt. -i
di~'."ip_,,f;lCHU(~..h·d~);
hdc.c~1.base

h<:k end t~ (::".'[;
.hdc .CHJl :;-s

bdc .-:.·md d~.i
hdc

(

(HDC ~lPRJ .DASE;
SDH.EGC

to hold inptti> tin€

·c/

to ho]d output line '"/
!• loop contra! */
ft loop control */

dj splay· the hde menil -:.,/

/* cont.rolier ,;ddr<cBsed al: p:runary

egsign step rate

para~elers

hddf'Ol .he,

hf!

hdd[Ol .spt
~

hdc. crcd. ;irt

S!l_ 1. SMii,

pbdc ·• hrlr .ci•d. baRe:

hdc iss1Je(C!MD PARM);
hd~:,

crr1-d, <-v-J

set

hdc _rRnult.. cyl;

d5'p _hdc _ ~t;~:J.t (_

hdc _cmd. hs

():

l 2- :15

gB·t

~n~t;j_on

key f0!·

~~~u=

s~:.e~1;io~

•J.~t,i:~.;-·.c,1.D.{"i

:-t:.f;~·~u

s·::J,t:ct;i_~).::J

Gt!L.FG;.:~;

hGtl[ho:h., <:11;r;:;,d;::d

ep~:

);':.

:i -=r {h:~.•~ __ -:tnd _
:.f {}F~5._ <:111.d. C\' !.

Lf!.r~[hd.(-

d.Aj .CC}

·· ::":; ,;-~;"' .C-:.'.

~G: .. ~~d

c~·i·t·•·;

\r:- -::.-.1...:. ,7_\·1····

-~gl::

... ,. __,,. r-=;t_. "" G;

:if (hd-: __ -:~:d 'c.y

h<lc. ~;md. s-u --= i.:
htl1: __ tseu.e (GMD_SCAN);

bd,--: __ ~i::~3n~ (GMD JtEST}.
·~·:ai~, __ hdcf);

"'At1.t.t

.fcJ

-'.:t.::;nmctIPl 'l.'O~iplet,e

._.,

int.Prleitvo(i1dc_but:f. 25Bt 17, 2. Oxffff):
;;iJ l c\'linders

i::,dh<:aJi
-f

he;ad,

Em'l E\'C

h<l~

i~s 1 1.c(C~D .SREl;);

-•.;l:I, i_ t. ___ bt)r: () ;

tt~*;h

/, wa_lt

SDH.'EGG·
.bk .. c:ccd _r;e_ '" hdd ! hik c·cd _d.2 J c;pi.;
trtc cF_d nn ::. · C·.

h•k i. '"""' ( G1•,D ... FE'>'A T) ;

WB.17: ... hdc ()

;

to <_:nrrent cy1 inde1
fnt

commar!d (·anpl~~~

!1~ad

< 30:

h~ad•+)

b.! eak:

}

dF>p_hdc .. n~atC:
{
HD~;"RESUL."T

>Lpr•::f~

-, .khdc~_:;:~s<..tlt;

cha·i:- ~--: l:u1e-fE·G]:

:'3-pr·:t~·:..tf \' r·lJ.Jr~{_-,

Sec+_;0y C<:Llnt

rilRp __;~'Lr (21., '+ 1. . c·1 Ln.~) •
sprJ::;tf(r-1 ~.Lr:e,

di.sp __ Ht.:r(2f.,

1 'S~~c-:t~:;:--

Nu.::;Ler· C::-{:~~,t2·o:·'

Hpr-ir:~·=' ( ..:;_; ir:~.-: _ ~'G:~' 1 ir;ut:":r

d.:i2r·~~0t;1·\£2.

;i1

£n;:r::.::tt l·"':)i!.r;_P

n::i.n.E')

'SDH

!1u,,~n

i~Bf!)_::::,ter

< 1 St.::.:.t.i.1~-~

'~·.:

epr~nt·f(vl}_ne,

d·i!1p _:-::t.:r{?A,;

l
1

Bf'I- ·iri-:-f ~. .:~lJ_uoe;

rfi.sp __ r:tJ (~~,?:

pres·>Rn):

1, vi..inr-::):

Pc~

r;_LJ.!~:f_:,.·;
'~LAC'!-t

.,__ Qr:ar;anfi

t:l:~_.:t-.;:J .:

}

Exnmple

int~rl~a~v(pb.

size.

~nt

J.l, ti.ll)

1_nt -;·pb;

:int

pt).i.nLer

Hi?~,

int 1__:nt~ ~
J nt1 i J:

buf·fe-:i::-

: "

i·• si.zc of but.Cex

•,,,, rn.i:r,t>e:r u.f ttectortr-

1 ·,- ·
f U J byr.e ' I

i.:!i~erlca;.:e-;

1rtt:!-:p1;

1.r~t

-;:;

*-p:f;

int
f..

pb + cnt.
c.;hile(y.··) ' p i ' ' ' ' f:ll'.:
E

}

/.~-

pi;;..;ph"'"~r;

if(p1>p·f

""'"' 8;

,~-p.i.i+

for(y

tf)

< il: y++)

p1·t·~;

~-.emp

pointer

$.tart d t i u
te"1p ct;unt.r·r

)

~
;..-,

i
t

/"· -fill Bi7'.e
oftset. tG ftJ.} ,./
set. fi1 J bytfles ·l:/

Chapter 13
Network Hardware Interface
Introduction to the LANCE
Th<·' network hardwme .inteifa.ce is locat('d on the VAXnwte workstMion 1/0
b•.iard. VI/hen the ba.d: of the \'1\Xmat~: '\'Orkstatfon ls open und rw optfons ar·~
in. the UO buard ls >isibl~:.
V/\Xmatc workstations may <·•mu.in different versions of the L'\NCK ·>11h\<:h
exhibit subth: difforence"J t•n
nntworks ""'ith high levels of traftic The dif·
ferent vprsions z>f bc:rdwJre
special treatment by 1ioftwllrt!, Digital
rncnmmend:-; tbat. you avoid
the hardware
Instead, appli··adons sho11ld ww the
scssim.1
ievd interfrH:e. DECnet-DUS s;;ssiun level interfoce. and thr Data Uni; imJ>r·
fnee to ncce~s the net."vr)rk, For additionl inforrnatkffi a1}01...1t tlit~1 se soft,~:are ins1~e

•
1t

•
~

B in t.hi~: rna11u.a! .

rrran~rni.t

Ntt\c~:ork h1terface extc.rna! interconnerf~
Nn .•,mrk Interfoc:r :;vsten1 bus intf:n.·1.mnect

r'\dditional Sourct~ of Inforinaiion

Fu:n.ctional Description of the Network
IIard\.vare Interface

~u:t:Th·var~.:~ i":dS(: ~=.·-1:~".L1tlr~.o;; fi

:;;;1

:sn1aO rn.unf-:0r nf discrete c~.,r-npn11;;-~nt;s:~ ~}-,&h~:!i!t bus n1~

r{e\:i~_,C7->;

;}n:J :1 f(::rdah~ ·n1.,.~{:; C{rOT1ec-ter n~0unt-c(i din?'i:t1}' ~Tx \l/t.Xr:u_att~
:rrrint:c-d :_~Lrc~_:.it: bf:oth·t], ·r he EE\JC c(1ntH:ttor f'.OPHt:i_:ts t!_h\'; .Nett~;<)rk

In.':f:rf~1ce t;"? tbt-~ ~--:~t-~1,-t:ffk,

Coax

Interface
~t:L!-(~

,,,

.•

CU.;_n_,; ;on CK"\f~t.~:, ~U nCUC'-'~ ~~

l_;;cla:>.;:::d fr(nr1 th{, otbJ:::·

an ~~ob~ti:Jt'I trnnsfo;'r!1e;-, 'i~!_··~~; Si)\ per··
nf ti1t di:~L'.i ifa.r:.sf(:rrpf~. cv\Jr
\\7It.h tht: L/~i..tJc·.F:, 'fhn Sl/\ fi]t,,_;r;:. J1(Jijt'
ccL~-'-~l.J~~-;;; :-~::i the_~ LJ\l~C.t~ 1)rC.!.i~t

l . ./,_f,Y\.~l~~- cc;n>/<'~?"!S ~.i~:t=> bett:;c~n !.~1e n.~~t..,,,,·~:>rk :'.}t:'-rt~~; frv~nJnI. ~;~-a.i th~~w ~.y~~tcrn
f:.:~rfn;~·Jt: T'h~~'. L;\!<(:8: ];9 ~.. he n~i~nat_r- i.J:tetf::~c.(~ h~-~tV:/f.~en f.I)i--; .af_~t.v~·urk
h..::1 ..n:iv..·a· ~~- i~_:;d th(;: r~_>-St ;.'Jf t:hr~ \./i\)Lin~~.te ··\"P~.-k-~r,at~nn,
.-~t·~-~

''·

Herelves in formation frnrn tht' SIA.

Cnnverts the sPrlaJ network bit. strernn into n
strenn1-

heck~ ~tnd removes the

rn hit wide!

enc bits

PM}S direct nwmorv 1u·ecs'i and a 24-hit·wide
the lnformti.tion \n ;nemory located in the

,,.

Pao;ses the dtii<f pad.•~t to thf' SIA for t,r;ini;;mission nn the Thln\'l'fre
8th torn et

Prog:ranuning the L;\NCE
The LANCE is t'.ontrolled by n HCL of four control ~md status
!/() addrPt;+;
2nd three dnht strurtcnek, The CSHs Are accessible ·within thio
spaci• and Urn duta stn.:.cr:urcs lo<:ated in the CPU rnernoiy address s:rnv·e. Afi.er
!.he LANCS b en:.tbled, lt.
ad<litional opernl:ing" pr1rnm12ters
the dota :struct.Ut(;S. ·rbe l~i\N{'l: a.cc(~s~es S;,'.':/~ircn1 tncrnor~r thruugb bus .;n~bitr.n
rio:1 l.:et\veen tht: L/\NCF_ (~PlJ n1ernor:r· rfffr(~:ih controller~ gnd the fH\,t,:\
Aft.er the LANCE

r.nanagt~s the; da,ta, st!'tH>

on the Thin \Nim t-:rhernet.
the ;_/,.NCE~ Jre:
•

•
•

inidail-z.ati.0~1 Bl1)ck
1Iect~i vf: and 'Tr-arJsrtdt
lJnt~~ BuffcrB

Jnidalizntion
p;:1.rarn_ctcr.s in. the ic
prnlifTH:~t'i<·~rs. •.vl1>_~h it!'~

d~:v~cr: i.:pE:cBt;iur~

the L.A._N(;f:: n-:-~-~.o~] !-hf~ l.niua1izr1ti-on b~nck. 'rht:'.-

hl<;.~:k Cf>~~,;jn"-.; ; ;·1-t:'

and Tnrnsrnit
rfh~_-, ~-e'('..e~\'C"- ;-~:Od Lt~E1.Sn:!t

are- t-wc1 ri.ngc ~t,nicti~n-~~: r;n€ -fr,!- u-1~
f:;;If.h t~nt(y i:u the

a:J:.i t:b"-~~ ot:1~:1 h:·•r

p\)ftions t..~f .rnerfl1Jry rest3rverl h.H' tn:_fff·ring p:3ckcts_
hnunti~.trie.s,

E-ntrl.t:H i~~ ~Jl~ l\c:::~~-iv~~ a_n(l

to the ((;;t;; buffor:-;,

L1_1rd C:SH..1 ;_~n-d < :KH2~ r~·hi!.'h '.dr;,~nti.fes th'~~ lcr(:£1 ,iqn of nn. ~niti~tH:z~n:ion
blnc:;, in :1;,;nu:'y,
S-:~t ~J1?:~- lf-JLT {Uld ST'f1.~i 1 bits in ('.S_HO.

vd1Jrh c«~n·;;.f'f:? the Li\i'Jt;1;: to
io;:d t~H:~ ~_r;_h\,....•;;Hti )~.i fror:<.-:: r.ht~ ir.i>'-_,lrdl::aUun hln(j~ unc:_i t-f• ~;fr't~'SS t.he

l\.JtrTrr
~i~:~_e T'::~;_r"'.,,,Vire E::tht:!TH~~~t .ct.erh~et~ ~·c~ni~:ir~11s

tn f)h-; rt::El~: 301))

~1cr~~!r~1cy of :t~ 0.01 !_:7:i.

:J.:t::! ~f./\)(1nEre net.v.:ork t_-·~.ard.~ti;d!.i:~ ~·c.~

tn ~lchi·i.'-Vf'- :::.:: ] (F~) c:.rceJn::f·.y·, dnd l. 0
'Tl:.~:ref•.Jf{~, thf;- r,-::!t-;vf·r-_k i:n-

10
ti.;.:n:::

Description
.1S ff;.:gLster~.;: tv1n-r. 1n ttv_:

~fju"~ ~t_:t.·Nork Interfa4~f.~

nscs thrt:e
LA.Nt B. and !Hlf' ir: tlie interface

in ti:f· LANCE

-iu:ld~t:s~ p(Jrt {ll,.-\l1 f, ?i.nd ;1
d.~~ta p(!=tr ~H..LH.-1 ). ·'fhe i_ntc::.rnai
Hre n_ 1 ~1d (nr ;-Y:ritr:t:~nJ in ;:t tv"'O st(~p opcrH~)(frL 'rh(; ~iddr~ss of thP ("-Sl-l .is
v,-rif·f)'.-~ll into tb-e ai.h-J!~f:!)S P(fft ~.RJ\ r1 r 'l'ht:-n the dat(j i:~ f(~~~d troff~. i'n~~ \.Vf.itte:n
in.Lo! HH) seh;ct~d t~-Sfl throu.gh the HJ)P {)nee ;,.;;,rith::rt~ the addt(~S:;; ;p rt~\r

( 1 SH~

Pritn.t:~t~}r

/\tij;l~~

~ /()

VO
i\<lii l\·~::;;

/\df.lr-!0 ~~

Por ~~ ~ HJJP~
L.,\NCE
Port ~RJ\.P}

HJ\V
H/\V

H:Vv'

1 G~ blt,
t +.;"~!it
t~3-bH

lH-biL
g-bit

t"l\\~':::E (::·srl o

t_,-A.t...:-t-:E: r:s11 }
L !\t·~·c_:;.:~ ( :F;rt
_L,f\f-J('F: C~SI~ :~

NI CS.H

at :_:_;~i.f-) L./\ N(;t~ Hf~P' <H:kln:..ss on the t_,.,... '\.X.rPDt.8 J./() h~1s .
h-;~~t~:·:d
t.hf: ::... F1.t~·n.ts <.~f L/\~.J(:F llAP t.• its -~ -~.L

_nt~~~diJ-~('.! futLJf} n·:'."\'L1izn1s- of h_ztrri;.vare 1nav nr;r
n_qJ1;t;:es, _r;r::)gTJ:-~·~.s ~butdd n.nt t~:;c. the aii;·~_s ~~t~G.rt-s~~-e:-:t.

Dnta Port O:tDP}
12

I
l,

------~~- "l~-.~~l

---- ··-- 'T

GSH JJATA

l
., ~t __

di)~t~~ int(~

H.!JP ~srites th(~ date luto r.ht C'.S_H ~-:::lcrteri. in
the cizita fnHH RDP rends the rhit:::t t~·on-1 thP r~~~n~
CSHL CSH.2, and CSH::J an: aecessih<e rmiy ""'hen
ttH~~ srr<JP b!.t. of (~SH(} i~ :::eL

if t.hc S'r()P bit i~; not set lr\·hih~
C81V, 11r CSH'.' Uw L\NCE rePJrns
tioo :etl~nv~ ~Jndefincd datcJ -~~r:d ;_~ Virftr:-

_ _L _____ _L __ -~ ' - - -

____ J_ _ _

.L __ . ·- ___J_ -

···--~~---

The

rnv

_____ _

CSR

RES

~-0

~L.

-· __ ...L ... ·-

f'SH · CnntroUStat.us
Sdt'ct
n
('SHO acccosed through ROI'
CSHI iH'.Cli5<S!;d thrm.•gh RDP
2
CSH2 access•'d t.hrmwb HDP
:1 ;. csrrn <oiCCE'SSE'rl throug:h HDP

STOP or fks BESET.

L3 · 7

Control And Status

0
9

INTT

t~ ,,.,,_,! ..~

I;:.; rr:~,c,~J;~;k~::~r

ti··;e ~;rr·(.JJ?

Bit

R'\V

Oe,.,cript.ion

1CSRO · cont.)

CEHR ·· C\1llisi<•n Errrn
0 = No collist(>tl errnr
1 = Collision error

Tlw collision Jnp11I: foik;d to activate within 2 us after i:I
trnnsmi<Jsion. started
tlw controller. was completed. Collision
ofter transn.1ission iH a tie~t f~aturc of the transceiver.
W

·cc,

!'fo effect
Clear:> this h1l

CE RR is HEAD/CLEAR ONLY
CEHH is dearnd by Btis HESKT' or

the STOP tlit

fl·HSS · lvlis<>>'d Prid.Pt
O ,. Receiver owns a reccivo buffer or th~; SILO bas not
overflnwed
:;;::: --rhc rocf:ivcr Io::-:•..::s :~ naf'kPt. bF~cattse it dc1cs not t)'WH a n:~f·-~ive
buffor and the SlUJ 'irns overflowed. indicatlni:; !oss ol darn.
:_~lLCJ c1\:prfl.oi-V is not. report.ed bee.Huse thE:re i~ no rr~ce\ve
in v.;hif'h to 'vrH,t~ th1.; s,tatus.

ring
\V

0 :-:~
i

Ni) c-ff.ett
(Jeo.c.;; th(-". bit

lf lNEA equ;ils l Ci!id rvnss P(jUHiS L an

l\USS i~; ftEAD:CLCAR ONLY. \USS is de•;;red

}{

MERH
[:rror
0
f-~; (~ n:cmory e:tTfJr
L/\.NCE is the Bus J'vfo'>t»r and has mY r•xEoivPfi HEAlJY
v·:it;hin 2GJ) tu;; after
Lhe addre.ss 'H1 thP l·:L:\L Ii.n.t'!S
\Vl-h~n ~1
Errnr i.;.; detPttett t.h~.s rereiv; :r r~nd
transrnittt:t arrj f)Jrnetl oft and ;n1 fr1l errnpt Js g·enerated !f
i"'JEA c:: .l.
1

v~i

n :-.;. _

Nt) t~ffe(-t;

I ::-:-::

t ~h-~rrrs th(~ ~.Ji_1

MEHH is HEADiCU:'AH ONLY. ME.RH
or
the STOP btt.

fHNT · Reo•:Iver Interrupt
0
l\Jo recei·ver i1:terrupt
flect:l'.-'(.'.r
\V

l\f i;) (:fff·ct:

Clears Uw hit

H.! NT '- I whcm Lhe status lor an
fling: is updDted.

in thB Heceive

ls
HJ!\T i:; HEA.D:CLEAH ONLY
is de<•rcd by Bns RESET cH'

!V~\T

the STOP bir

T!NT · Tnm!,mitt.er l:Jt.errupt
O
J'·~o t.rnnsndttcr
\Vhl_~n the statn~· f1Jr nn. e:.ntr,v In the:~ "Tra1P.in1~r fJB~:.:c~--~ptc."lir
lS

t\o effectClt:ar~ tb~~

i:-It

IJ!NLA
TINT is R!:J:..D;CLEAH ONLY

th(: STOP bil
0

l niti{}lizt~tioa
nr)L
L/\NC:E hrt~1 ~~f1Cnpleted Lhc~
~t:;:u~r.,ed. hy
ch<:; i.NIT hit. \Vhen IDUN !~; SH, the LA.NCI': ilar;
inii:iaEznz-.irHt b1cJCk frO!D rneiC.f)f~i ~--•nd stfff{;d ?J~e nev:/
1x:i. r ftrflvter~..

U lNEA -

'\lo <(~tf~:c;:

C :ev~';-: th(: t:~t

h~·~s ~) 1_-~c.u~---~-t:~<t

1_!\if~i\ ~~:1

B _,_'\.JJ L~

:uJd tt..:-rn.

the STOP hJ l.NTft "

Bi.t

Ri\V

flivV

Description

ICSHO - conU

IN EA · lnternipt Erwble
0

The !NTR L l:O pin will hl' high. regardless of tbe state of
JNTR
lf ! NTR = l , the l NTJ1 L I/0 pin will he low

!NEA ano ..vs the !NTH L J.iO pin to be driven inw when tht;
luteaupt. Flag is set. U !NEA =dJ nu-;A J,., deared
Hus RESET

r1r setting the STOP bit.
llXON - Heceivt:r ON
0 ~-- Ileceiver disabled

R.\JIN
0 wiwn IDON "' L if DRX ·~ J in the JV10DI;; register
or a memory •.)JTOJ ~MEHH "o]) has occllrred . RXON ""' l wlwn
STl\T is set in CSHIL lf rmx 0 in the MODI'~ field of the initiali·
;uifom block [5 !DON ·:cc !..
RXON is de::ired
4

Bus RESWf nr setting- the STOP bit.

TXON - '[nmsmitter On

O
I •==

Tr;rnsmitter enabled
T'nmsrnitter disabled

'When TXON = 0. IDON '"' l. and DTX = 1 in the MODE rngls·

tee an Undel'fl•>r'i or Hetrv error has occurred dutlng: transrnis;;;ltrn

or a nwmory error lMEHH.i hni:; O<.'.nirr~;d.

TX.ON '"' i when the lNIT bit- c~ L and when STRT = l if DTX
:·. (I in the MO.DE register in the initialization hlock TXON i;;
cleared by Hu~ itESET ur setting the STOP bit.
\V
H

TDMD

Trdnsmit Demand

The

i.s sent subject to th<) l .6·milli.secnnd polling· in-

P;1<_'Kt't jq i.rnwm1itted witho\lt th•;
h1tervaL 1 IJ mi.lliseconrl»

delay of th-.· po!Un;r

f\o effect
'I DIV! D, wlmn set. 1·auses the LANC I~- tn ;11;cess the 'Transmit
i.vitbrnit waiting· for the
<'lapst'. TDI\HJ need not be iwt ·to
it. n1cre1y
hosrens r.he LP.. . f<C'.E: re:sponse tn a ''frnnsrnit ''"'"''ini•rw Hing
h1scrHon by th(: soft\·V-arC.
TDMD is deared
Bus HbSET or
:i.s cie~~rcd by th·e LA.N(:E: aftt'T t1v.::
:tK~.f'.i'.:'~ :-.:ed.

(CSRO · nmt.l

;;

H/IN STOP
n

No offed

l =

l./\NCE disabled frorn uH e:dernal. nttivit;y a.nd internal
cl8Hred

STOP set ls t.hc
o!
LANCF; remains inactive ;ind STOP remains set until tho STH:T !•r
INIT hit is sec If STln. !NIT. and STOP are an '>et togcth•~r.
STOP will override 1he otJwr bits and
STOP will be seL
'.viH tern1inat,e £11! L_,:\ NC[; ~ictivitit~s
! N lT or STHT.

STOP is ck:,·lred by
WV1-'

STRT - Stiln

STRT eiwbl.8s t!H; LANCE tr, send £Jnd n•<;e\ve
d;r..,ct P1•'1r,nnr U''.<>1'S" ·1n'.' do b«ff+·r· "''·'lrl'll!"''i1Pni
ci~~~rs. t,h;~ Sfr.<;1~·- t·~it.'~ S~rrtrr ~~,d- irii;r ~rt;. s1;t ...
function ;,.~,ill bt~ executed first.

STRT ;,, R.L'l.DiWHITE 'WITH ONE ONLY.

bit has no dfe".t,
Hu;; HESFT •.H'
{}

ll/\:V .i N l'T

I.uit:i.nE:u~

{_1

.No i.·'ffect

1 ~

St~n ts

L:\:'1CE ~nitiaiiiaUon and reads init13Jj7,;nJ(~D ;;Jock,
Il'~rr ~Jear;S

thi:J ST(JF"' b~t

the S'l'OP bit

Contrnl And Status Regish~r 1 (RAP ::;::c: 0
14

r ·· --, ·- · -r- ········ ' I~~:;,:~~- r
!..~ --·--·- ~ -

6
~-··r----

-·r -

--1

_ L ..- _ ... _1_ -·····-·-·_J____... L _____ ·-···L- -·- _ ..L ______ ....J. ...•.- ··-- J

5
--

·-r~---

_,___ --r---

~~--~--r----~---~r--

IAUR(11)

L _____ _

Hit

T!w lnw·order l G bits nf the addres'l nf the first word \lowest. o.ddres.:s_J in ::J1e initiaUz.ntiun hlock.

'vlwn the STOP bit of CSfl.0 equ<;h t. lt STOP = 0. an accPM;,
rt: turns

tk:n is

. a Head opcrntion returns undefiued dat0 and n ',\' riti.c operaCSRl i5 urwJfoctcd
Bus Hf.SET L

Control And Status .Register 2 (Ri\P = 2)
15

___ L __ . ···- ·-· l_~ -----L---~ ____ -1.. ____ ...L

]

~~--L___

.L. ···-···~---'

JADR (l:U ts 23 -16)

7-·H

z'\.ecessible ooly \Yhen S1Y}P MQnHls l ((:S1lOL ~.f S'f()P
0 an a~.;i_~e;~s returns
rtE/\J ry" a R.ead opt~ration return~1 undefiaed dat~'}_ and a \"'/ dt-e (~pf-!rnti.nn ;.s
1

ig~lHI"t:d.

l3- j 4

Control And Status Register 3 (RAP = 3)
15

~---~--1-------------,-------------r----------T--

-- ----------,-----------

--1

RES
---~----L

___________ _j __ --------- !_ _______ l _________l _____________ L ____ _

RES

Bli

2
BS\IP

__ L_ ____

UCON

HiW De!'cription
RES - Reserved {Alway" 0)
:Hi\V

BSWP - Byte Swap

0
I

The LANCE dues not sw;1p hi!f,h :md low
The LANCE swaps the- high and low bytes on Ot-.!A data
trrmskrs hdween the ;;;!LO and bt1s memory,

BS\VP 11llows thl' LANCE tn operate in systems that consider b!t;s
58 to be the!enst: <iig·nifksnt byte and bits 7-0 to b~ the xaost
significant byte. Only data from Si.lo transfers is swapped, the initiali_zatl.nn block data and rhe Ring Desr:riptor <-'ntries are NOT
swapped_ BSWP is cleared hy Bus ftl'.:SET or setting the STOP bit
in CSHO.
RI\V ACON - ALE Cont.ml

R,'W 0 =
J ""'

:\LE is a:,serted high.
1\LE is :_1s.-.ertcd lmv_

ACON defines the nsscrtive state •1f AL_F: when the LANCE is a
flus 1Vfaster

ACON is cleared by Bns RESET or setting the STOP hit in
CSHO

13- J 5

EH.ON
0

i!O P''• .h
B!~1 1 I~

Bf\'t n i

B:.ISJ\f{() !

I~ ~r·11_~L

J1(} .Pi.n 17
HOLD l_
L

11(~().N ~s ·~h!arr-~d

CSI!.O.

Bit

C~-BR~{_ -~,,bkh aHo:>.~·/3 r(~defin.it-i<~n t:rf t}:r·

bit:~.

bes H'HlSh:f rn~,erf;:;+_;~~f}~ rontains t.iu~t:.:;
hilfchvrtrc

an~.; u:;~.;d t(.c Cl.~Stc•n1~:u:· t-t;rt.~·-dn

t:-1e L:-\T'i(~E ~-;;hen it ts iii hus tt~a~t. fn n1.t';ir_fe_ 'The

~-"-';i~n th~·-~

S r'(H-~ .bi~ 11f ,C'.:df{t) equei::_: t ff ::S'T()F ~ 0 . an ~JCl>.--s~
r~ttnn;.;.; undf:finf.d dtrte ~:u1d a ""t.<~!rite ~;pfn-.{i1

flESE'i'

csrt3.

NJ csn {OCH8H)
]

RES

SET

Bit

LED

INT

RES

CI£AR

CI.EAR

H:V\/
!\lo effrct:
l 8]) (iLi

\5./

I JLP lndk:ato.1· Cknr
!.ED CLEi\H
O .~__: ~~ (J (~Hee~
! :::: LED oH ll1 ov.;m on defoulti

::.!

(Pnwf'r-on (fofoultl

RES - Hr:cW:'FPd 1.1mddinedi
HES - Heserved (unclc1foh2d)

indi'.1idual bit-;;et ::tnd bit-clear
a bi!, invokes its Pfffti.e.uisr s+~t or ck.~nr
u 0 to H bit does not invoke rhe nr.n.,,-1,,
func.rJon.
0 tn botb ser and -:Jcnr hits
k~t1l1/f~::i tht~ stntP- of tbat function
end ck:n r bit~ of n
ta;:1.i::. tunct~on.
J t-o both t1J(: sot and cienx bits i.:1. not
1 ec>:;rn :n:lCn(~{'~d

Initialization Block
inizializatinno the- f.:,;\f~CE rends
Vlhen ttH~ JNYf bit Ln C'8Jl0 is ~el"" t.ht-. L..~\T\!C.J::
re2ding dle initi.nUzation
;}1(1"<;k. Tu t:ffJ,...~11:-T~ p~opet rnu·fn11ch.~r ird~·iuH:r:nt.ion n.nd Lt\_;1<.J(!E oporut.h~nl the
pr<;gr£.~~s:1 .shcn:dd. ~(~t the J NIT' bit and thtin set- the S'rR~r- hit.. Aft~-~r
n~;,ds the irmiaU:i:aL!on blod;, the
~-r I!,,~F~l\ t~q~1ai'.':::

L·\NCE ~'.HS IDON !n CSHO and
L t.ne I1t\.N(~f~ aJ:.;1, generat;e.s sn ~nx,errupt .

1'LEN '!.ORA. (23-JJ;,
TDRA '.Jll<\101

H.LEN-HDR•\ r::i.itn
1tDJt/\ i 16--00~
LADRF WH8r
-L . ·\1) HJf ; . ~ '7-3 :t
.L/\.L~~HJ' ·:~~ l "-i ;:J~
_f

1ADH +22
IADfl +20
lA..!.>R +HI
L\DR + 16
J_;\IJR -+- t..-~
IADH -+ l 2
lAJJlt l·· 1.0

P/\l)R.147-~i2!

LL>}.fJR +og
IADfl !-OB

PA.DH:(:>,HG;

[:\[)!t +():).

PAilH fl l!-OGj

U\DTI Hi2
IADf{ rOO

J--01\f)H}~ {Jff,,00!

l\10 n L: '10-001

1\'lode Field
(Initialization Block, Offset OOH)

-··--·
14

PROM

13
.RES
_ _l_____ ___ L~.--- .... L

RES

DRTY

COLL

DTCR

LOOP

DTX

DRX

B\t

PHOfVI - Pro1nistut1H:<>
0

n1;.itcb1ng-

(;!'e

AU im.:oming packets ~;H'~' "'···•~''".'°'"'
14-7

RES

Hr;served

INTL - lnternil.l

11\TL i.s used wir,h tbe LOOP \bit :~i to determine w!iere the
b;,K~k .i~ to b<' done. 1niernal k>oplmck allows the Li\N('E to
its fHVn transn1i.r. t~:d par.:kct. 'The 1rutxirnurn. transrnit
!.owed
k1onbr1ck is ;y2 dfJta
The
add~- 4
of i;nc t.o H1t•
if UTCRC""·O and therefore rhe
1·eceivc
contd he ;i(}
!NTC l5'
valid it LOOP '"
otherwis"' it 1.s i.g111.1.rt:d.
!NTL

.x·
0

LOOPB/\C'f\
_r.; o
, nor.rn~~l
extcriw!
i.nterual

Lf\_N (-_:I;~ ~-J_tt.e;110~-s 'r_ t> rf~tt;JU.8rttis~if}D8 1J-t 2
fir_:;-t. •>}Eis~oii l;c_·forc
~f

tr£~nsn1iss~on ;1tb:~rnpt _ a

there

R-etry Errnr

'lrl'R.Yf is
ff\'1 Lt~--~:

("\J~ :L - l· '::~fff:'." r·oEiF-~ffP
r~

(;;j :£8!t~;I~

1:t)~---

frJi (·i~6-

rncde ·vvhc11 f:t)LL
:--c:r_y ~-~-rot if:<

to tht~ rec~:I-ver ar:d Hf) (:jl( L~
r.ran:'iff1itt*.?"cL

.:1 C.flf~ o.n-_ th(~ t..r .~:ns;nlt.t(~d
a_nd ~,he Ln~nsrnitter~

flT-Cjl ~ 0
·"·~·.,:i,f·ri

·.; -.---·•. ,...~.!- '-~
e~H1ri.(~f; J-~·~-;i-'-i::r.?t--t:: ::· _ -.. :_,·,.,·. ,_•..:_·/•_:.·_;<'
f,_
~

tc1~t:oi"~'l::t d::.;~-;:::

n:.~ceivf!r

"1F

I;_<. . !~-?

f_'.

--.."

nt. t:he t~£HYr.f: thn8, ~f_tvert~frire, the

LH.; Cll('. (:heck. The

v,.-'" it.ten iTtc1 nJ.-~~:-nory i_nd rfHJ be cl·HJi::l~ed

(;_fl(; ,~I-~:d dot~ an-:-,
thf:~ so+'f:v;:a1e:-

jr)rJphack. th(J r:-:oft-rvarE: n1u:...;t

data in t.11(~ tTansrn.it: bt1fh~r.

a CH..C

Bit

l>escription

I.Mode Fl.dd · r1mt.1

L(IOP · IA)opback
.~
LANCE npenites Jn normal mude
LANCE operates in tull duplex rnode for test purptrnes

LOOP ~.1Hows the LANCE to 01mrate in fufl duplex loopback mo<ie

for t~~st purposes. The maximum transmit p~H:ket size is limited in
32 data bytes. The received packet may be ::rn byte'l becuuse t be
LANCE
adds 4 CRC
if DTCRC=(L
[luring· loopback. the runt pnc!let filter is tfornhled becnuse the
maximum JJacJ;ut is forced to be smaUer than th•.o mi.nirnum 'lize
Ethernet pricket of iJ4 Bytes.

LOOP '' l uilows simultunenus transmis;;lnn and recepthm for ;i
mes8al!e constniined tn tit within the SILO, The LANCE: waits
until t.he entire m+;-,slig·e is in the SILO hefore st:rfol transrni'lsi;m
'Thf~
data stream fills t.lw SILO from behind as it
is
emptied.
the receil·ed me8sage out of the Sl LO tu
memory d(tC'S not bcr;!n until recept.ion b11s ceased. In Joopback
mode. tnmsmit dato
is not nossiblc Receive data
is allowed,
of tlm receive f;ulfor
In normai (>porn·
tion. not

the receive buffers mus1 be ate least H4

long to a!low time fot bnffrr lookahead.
DTX - Dhnble •.he Tr,;nsrnitt1c~1
LANCE c:m access lhe 'frnnsmit
l
LANCE; docs not access the Transmit

thereft.H"'~-~ no tran~rn.issions are

the TXON bit in CSHO ;vhen iniLaliz.at\.m is complete.

DHX

Ois;.;l;h~ the

Her:elver

(J -

H.t--cPives

LANCE fl'J•ccts irv'.oming parki'ts m.id does nut access the
Receive De.scriptor
DHX ~"' I cleMs Ow HXt)N bit. in
c:sno when initiblization is complete

The Mvde fidd allows <literation of the LANCE ope:·atlng paranwter'7'. !n
nnr1nv.! oper;1.ticrn. the ~1·1(14:il!
cleHr.

Phyi::;ical Address Fleld
Hnitialization

02tU

PP1I)H'., th(:! t~FVNL~?_·_k Phy:>:i".":t1i _•\dd_;:·f~~I-5~ }.S, t.ht?::;ci tt:Jt~ l:/\ t-\C:E;_ P/\.I)llH)f rn.::.r;:;t, be zt~ro.

Logical
Filter Field
ilnitializaOon Block.
08H)
LAD RF.
-r!1"H~

.:\ddn:s~:;

F'!iter is ;_., t34-h·it nH1sk that iu-_-,cept.s
i\.ftcr nH 48 bits of V.1t~ n.dd_ress h~tYt
iJ bit'.< of the iesuitunt enc
_in
Add.r_-~~::.V·; Filter:. l f th~; sel.{~cted. iiiter hit e-qu.ais 11 th.t· ~H34!J f:-SS Ls
vx•d tbe
is put i11 mr:niory. The flrs<: !:.M of Uw
ad·
rite.SS
J.Jdd~·eSfL !f tb_(' first bit ~S 0} it 18 a
dtes~; .and i·~
tbe
thE Lc-~t-l:Jiiz.1.ti\_~n Hlnck,

Receive Descripto1· Ring Pointer Field
(Initialization Block, Offset 1OfH
31

r - ---- -----T- -- - - ----, --RES

RLI~N

_ t ________ L ______ l ___ _

' - - - --- t -----

r--- -----.------- -,--- ---

--1

l8
-r- ----

RDRA

L___ ---- _L ______ l
]~

___ , ___

-------~-L

-.:--~--~

_T_._ ___

_________L ___ --~-L ___________ L~---------L
12
11
10
g

~----~-r---~·

-~--1~----~-·-~--~--

-~~-----,'"------

----,·-~---~~~-~!

RDHA
____ L__ ______ J _______

L_ ___

)

- .L ______J_ ____________ l_ _______ J

HL[N . ru:;CI:;!VV HING LENGTH
'Ih·E nu1nb0t< of entrit::. in r.h~~~ H.ecei'/C

nf 1:. .\--c1.
ftLEN
N un:dJer ot _EnttieN
0

4
7

Transmit Descriptor Ring Pointer Field
(Initialization Block, Offset 14H)

r ---·31

30
··1-· - -

29
. .,.. - - . - -

··r··

26
25
24
·-··---·-····r ..···-----,-·-----··-- ·1

TLEN

L. -·-· ... L.
23
- ·---r--

RES
j _______

. ......L..•... ____.L_.

22
21
20
19
18
17
16
-----·r- - ·--,----- --··r···--------y ··--· -r· --··--·-·--;--·····-

·-··1

TDRA

. __ l. __ ....... --1. _ ........ .....L ..••. ___ .•L. __ " ______ .L ......._____L _____ ... J ___________J

7
I ...... ----,

___ L ..

L. ____J _____ ---1 .......~1.. .. __________ J __ ···-··

T!JRA
!!j

L __ -~-- _.

_t_ ·~--~-- ----- -- t ----· _-~ __ ~L-. ---.--~--~ ,.....l____ -~- -~---~ _J_ .~ ·- ·----~J.-~_. - ,~.~"~~- j~-··~~ ·--~~~-

iT-rnnsmit De,,criptor Ring Pointer Field}

Bit
TLEl\

TLE N is t.he nurnhcr of entries in the 'frnnsrnit Rlng·
as H po-vver of tv.ro-

Number of

'T_LE-N

Entries

{)

:-i

28-:!4

ru::S - Reser·vpd

2;',--0

TDHA - Tr;tn~mil-

Hing .1vldress

TDRA is the base l:'ddress Hov.-n:t address) of th<i Transmit
Ring. Beun1.s!' tlw transntit rings nm.'lt bf' alig·ned rm
qua(J..yord h<xundari_es~ these bits i.?·-0 n1ust bf;; z.cr~)s.

Buffer Management
Huffer
org;anized ;H; ring strurturns in memory. are used for buffer
inanagcmcnc Tbc buffer descriptors, also called message descriptors, are four
words Jon?; and point to a buffor. Two rillg structures am 1Jllocatod for the
LANCE-: 0 ring of receive message d~>srriptors IHM.Dsl :md a ring of transmit
niessage descriptors iTMDs/, To transmit or receive packets. the LANCB polls
each ring stn1ctlm» 'T'lw LANCE also enters status inform.at.ion in tht\ descriptor entry, The LANCE is limited to looking only one descriptor entry ahead oi
the one with whkh tlw L/\NCE i« currnnUy workin~;.

The location of tin) descriptor rings and their length <ire found in the initial.iz.a"
tiun block, which the LANCE accesses during- tbe initialization procedure.
\Vriting a 1 Into the STRT bit nf CSRO camws the LANCE to start accessing
the descriptor rings and enablei;; the sending and recei\'ing of data p.:.ickets.

The LANCE communicates with the datn link luyer program through the t'ing
structures in tnemory. Each entry in the ring is owned either by the LANCE,
or the dat<• Hnk iayer program. The ownership hit (OWN) in the message
entry det.ermi.nes wbn owns the m1try, Therefore. ownership of a
descriptor entry ls mutual exdusive, To g11in ownership nf a descriptor entry,
the .:ommtmications partner iLANCE or data link layer program) must wait
until the owner
owner;;hip to the comrnunicati<ms partner, Between tlw
t,lrm' <l communications partner relinquishes ownersbip ol a descriptor entry and
rhe t imc tlwt cornmunkations pnrtner regairni ownership. it nrnst not change
any dB t.a in dm descriptor entry,

13. 27

Descriptor Rings

IVIernory

13-1 show" receivt: H.nd tnmsrnit
de:.;cdpt.nrt< e1Jeh.

Higher
AddressE'.S

TM!J(127)

M
1

I
Hase Add:n:~.ss
of

TMD{O)

•fransroJ t

IU 'fhf'r
Addre.sses
(

v
g

N
G

Receive Descriptor Hings
li:ad1 descript(Jr in a rini~ in nwmory is a 4 word t:ntry. The format of the
nx·eivp dcs•:riptor foJlows.

Receive 1\rlessage Descriptor 0 (RMDO)
1 :i

--r·----·-·- ·-· r·-----·tJillR
..1 -· ·------J.~

-·-· _ _L

B.it

15-0

-~.L

.. ____ , .. t __

()

Description

LADH - Low Order i\ddrnf's
The LA.DH nf the buffer pointed to
t.his rlesrdptor. LADH. is
writtten by t.he ~,nftwonc and undrnnged by the LANCE. This is the
rnernory location lo plm:.e llw nex.t received nwssng€L

l:l·· 29

Receive Message Descriptor ·1 (RJVIDU
15

OWN

! ERR

FRAM

OFLO

CRC

BUF'F

S'.l:'P

ENP

r--··--- ·r--

IL _______ IL

HAD.R

Bit.

OvVJ'<
0 ··"

eutrv fn.vne<l hv the, dt?_ta link lave!-- f.ioftwart:
emr}' owned · th'-' L.A.NCE
··

The L/•NCE dc<•r"1 the (Ji;VN bit ilfter fUJin/£ tbe buffer pointed tu
the desa.iptor
The softwure sets the O\IVN bit after
emptyim~ thi~ huffor.
the LANCf; or sohwnre has relin·
qutshed ··
buffer. it rnny nnt chanp;e any field i.n the
entrv.
f~HH

.. Error
Thf.• fom· b1ts. FHAM, OfLO, CHC or BU FF ar':' all eq1wl to

One or more nt the four bits. !'HAM, !)FLO, CHC or BtTF,
. . ..--~
to- one~.
Fll/»M ·
0

l ~

Errur

No fratnit-ig- error
'l'h~~ incn_1n{ng pack.et containFd H non

bits nml there w:is
A CRC error on rhc
Ff{_:\tvJ to eqn;il

bits in the
the :1nftvvafe,

13- 30

Cftf: error.
is a nec·os5ary condition for
rnultipli~ of t°'ight

(('Ven if there \\'BS ~1 non
fH,_.;\JVi is r;e~
the

~nd c.h~z~rcd

!RMDl · eunt.I

OI ·u)

Overflow Error

No overflow error

1 occ

The receiver ha~ lost. all or pan. of the incoming packet be·
tausn it cannot store tl10 piicket in <.1. memory buffer before
the internal SILO h<is overflowed.

OFLO is sHt. hv Uw LAN('E Hild dei.1rcd lrv the software.
ll

CltC · Cvdk H.udundancv Check
O "~ N<) CHC ernw
.
l '"'' The n·•·eivcr dctcncd a CRC Hror on the incoming· µw::kct.

enc is set
BUFF
(l

.·o

t ""

th<) LANCE; an<l deared

the software.

Buffer Error
No buffer error

lhe IANCF: doe;; not own the next buffor while data chain" received Dackct. Thls condition could occur if the OvVN
nf the nex!."buffer was zero or the LANCE coulr!. not acq11ire the next. 81.atus before silo overflow occurred.

BUFF is set bv the LANCE~ :.md dearerl
STP · StHrt; of P;01dwt.

O
l ~"

Thi.s is not the Jirst buffor the LANCE uses for this ixickec
This is tho first buffer LANCE uses fnr this packl';t. it is
used for data chaining boffers.

S'IP is set

the L!\NCE n.nd cleared by the softwani.

Et\P ·End of Pac.kn

0 1 .··-=

This is last buffer LJ\NCE nses for
This i." the frwt buffer used bv th<~
i" used for data
buffers.

nc1th STP and ENP set indicate that the packet lit into •me l:mffer
and there was no d:;t3 chaining. ENP is set by the Li\NCE and
rkared
the softwnre
HAUH: - High Order 8 Address Uits
The HA.DH of the huffor point<id to by this descriptor This field is
\Ydt.ten by the snf!wnrc and unchang«><i
the LANCE..

Receive Message Descriptor 2 (RMD2)
15

10
9
·1·-···--r ···-·-··--,-------1
BCh''l'

........L _______ J

I -----··-r ---------,-

!L_____

--~~-,---

FICHT

J ----- - __.L~-----L ____ _j __________ j__ ____________L ____ --·-~·----..---·

BH
Must !w ones. Thi~ field iA wdtten
by the LA.NCE.
] ; -0

BCNT - Ruffer

the snit.ware and \1.ndwnged

e Connr

BCNT i::< ibe
of the buffer pointed io hy this descriptor exprn'>"ed <is a
coniptmrnint number. This field is written
ihe
~of~w;u·e and. unf'hanged by the LAN('f:. The minimum buffer site
lt' h4

Heceive l:Vfossage Descriptor a (RMD3)
15

-T--~-

MCN'f

RRS
L _____ - - ,.L ------

HCNT

Descl'iµtion

lci-12

rtES

11-0

MCNT - Message Byte Count
1\1CNT is the iengrh in bvt.es of the received messa~re. l'v1CNT is
valid only when t5RH is <-~lcar tmd ENP Is set MCN;f is wrlt.wn hy
the LA.Nt~.F~ and cleared by the software. \.Vlwn data dwining,
Rl'VlD3 is oulv loaded bv the LANCE wlu.•n tlw status of last buffer
is updated. dnly tbc st«itus word is updated for the other buffets
in the ci:Jta d1ai!L

Transmit Ilflscdpto.r Ring
u.1 rnernor\/ if~ n 4 \-VOnJ entry. l~ht:: fo)rrnar. of the
foUoivs_

Trnnsmit M.essage Descriptor 0 (TMDOI
15

-.~.-I

LADR
_j_ ------- - _!_ _ _ - ----'--~--j

LADR
i
t__ - - __ J_ ~-~---__j__ ______ : __ -~--- _L.,____ _____ "~

The LADH uf the buffrr
to bv this
'lv~·it:tc:~f
t-he ~,;oft1.,_:art:; Ptn~l 11£1el1::111gjid

--~~·

Transmit .Message Descriptor 1 (TMDl)
15

1_·.:: J·-..~·~1-~s

f -·-

6
T--···

5
··r·

___ T __ _

UADR

L~---~ L--.~~-L
Descri pl Ion
!_;~~

()\VN'

o eoco
I ~

Owned bv !he L\NCE
Owned h}' t!w datn link

software

O\V"i lndh:<ites whether the descriptor entrv is uwn;;d
wnrc iOWN :·~ Ot or bv the LA.NCk !OWN·= 11. The
Um OWN hit after filling the buffer pointed to by this
Tbc LANCE dears the (J\VN bit <Jfter transmlttlng the contents of
the buHer. Neither the software nor the LANCE may alter I.1
entry after relinqui.shing ownership.
i.4

EH.R - Error Sumrnarv
/\!l of LCOL, li'AR. UFLO. im<l ln'HY equal 0.
J. "'- One or more ol: LCOL. LCAR, UFLO, or HTRY equai L

u "'c

EH.H is set by the LANCE and cleared by the 8oft·wgre.
l'.I
.:2

\1lHlE

0 -=
:. =

Onf' retry m less was neerfod to transmit a packet.
Mon) than one retry was needed i•• transmit. a
the LANCh and cleared hy the software

ffJ\lDl · conU

ONE

ONE is set

the LANCE c;nd cleared bv the softwar~:.

l)E'F - [)e·terred
0 ·~ 1,fie channel i.>:t
for L,:\J~(~E to trausrrdt a packet:
T'he c.h~1nn.z:~i ts bu.S'i/ v-..·hcn the L1\J'-.;(~F, js
to t-r£u1srnit a

s1·p ~ Stnrt ot PntkeL
No1. the flr'.<t hvffer LANCE
l ::::: 'fhe tirst buffer r.o bf; u;:ed
is c1sed for d<>tH

Fr~ P - End

n
J.

of P£ickr~r.

f\iot the 1.ast buff.er Li\NCE
c.:

The hst bul.for to be
;~ us~~d °h)r data

H both STP and E:NP are
there· v. 'a~ n.q data

fit inte! tJDH huffPi' arid
the ~nft\vare .nnd 1u1~

8 Addi"~"" Bits

H!\DH is the high-nrder fl addn;ss bits of the buffer
this
H.i\DH 1~ written hv th<c' software

Trans:m.it J\:1cssage Descriptor 2 (TMD2)
15

l 1,

r·------

,-.- --·· ·-r ·---·--·

a
~-l

{

BCNT

1-. ·-··~···-·--L ·-- __J

llCNT

Bit

l. This field \:+ set
l J.-0

BC \T i:.; v•ritten
the ~;oitwarr: nnd nol a!.frcted
The rninlrnmn si.r.e of the huffe1· .i.s 1;4

the

1\lessage Descriptor :J <TIVlD:l)
12

1.5

---- --:·---------r-

_~: LR=,_·_ _,_ ______·_ n~R- - ---

BUFP -•--t--r'"__
-·1_.o____._ ___ I_?_E_f_, --·--''----I-.c---o"l

-·
I

r__

TOR

BUFF - Huftr>r Ennr

0 o-'
l '"

No butfet· error
L,-\NCE. :.hning rransmissinrL doe~ not find t}w ENP flag in
the current butkr and docs not own the m:xt buf±er. BUFF
= 1 <.Jso if tbe LANCE owns t.he next buffet· but can not
read the m·.xt huffor'i. status panm:ieters btefore the silo underffowecL

BUFF is set
the LANCE nnd deared
Buffer brrnr occurs. un lJnd_erfhrvv 11~rror
occurs because the
trnnsrnitter cnn:inues w read data from the silo <.mtH empty.
i4

UfL(\ Underflow Error
0
Ntl! uxv-.terfkH-\ error
The transrnhter h'is tn.Jm:ated a message due to lack of data
frorn memory. t:i•·Lo 1ndicat-es that the Silo has emptied
before the flnd of the p;icket was reached.
UFLO rn set
the LANCJ<; and des.red
the snft".1,-an:.

LCOL Late Cnlli:';inn
No collision
0
A. collisifm on:un:ed after the slm. tlme nf the chimnd has

The LANCE does nm reu·v on late collisiolls. LCOL is set
LANCE ;md cleared

tlw .sofhV<irn.

the

fl'MD3 · cont.I

Bit
1l

LC/\.R - Loss of Carder
0
RENA cloes not gn false during transmission
l ,-.-. The carri<~r presence (HENAi input to tlw LANCE goes false
during a transrni.ssion initiated bv the LANCE. The L.:\NCE
does !wt r<>.try upon Loss of Cai~ier.
LCAR is set

the LA.NCI::; :md dearer! by t.hc software

RTRY · Hetrv Error
0 ·· No ren:v error
l c;; The transmitter ha.s failed in 1G attempts ti< transmit a
message due to repented collisions on the nwdiunL lf DHTV
co. l in the lv10DE regit-;tcr: RTRY sets after 1 foiled
trnnRmission r:itt1~mpt.
RTRY it:1 set by the LANCE and dearcd by the software.
9-0

TDR

Time Domain Reflectomct.ry

The TDR shows the stat~: of an internHl LANCE counter that
counts from the start. ot a tnmsmi!lsion to the occurrence of a ,·1;Jli.
sion. This vnh.ie is useful in determining the approximate distance
to a cahle fault. The TDH value is written bv tlH~ LANCE arnJ is
valid only i.f BTllY is set.
·
TMD:3 is vnli.d only if the LANCE has already set the ERR bit of TMDL

Network Interface External Inten:onnect
1"-hc \I A..,Xn1;rte n1:.twork bardwrt.rt: Ci)'fHtec-ts h; thr~ nt~tvc,.,-or};:: cqRxiHI cab-1£ through

a BNC' ,.f-Ct.)nnectr_,:r. ~rhe 1t.:/\.Xrn~te netvvork ha:n:.h·v<:irt~
·rvith LE;J~)E
iJ02 a 10.B/~~sE2
1 he Cflb.ir:;- shield is i~oiar-1£.~d frorn the, \/,::\)<:n1Gt:f:
ksg"it~ :nnd chr:.1.ssis
by tht.~ jn.t-en.'.~.!nn~~ct
equ.ipn1_e1n T'ht" V_._. \);~wJ11t.:t:'. vvurk(it.adon ·does noc cont.Hin a GO·"()bfn Jh-H_'.: ..
1

ter:11_in.aU~Jn

The 50-ohm line tern1inator ntu},~t- bt-" ~uppHed
by th(; r:onr..et.U()ri_

:as re~

Bus
-The~ hrrn.hv:1rP i.nterfact~ uses the

J Ci-bit hnd
It. c~~Jt:r:::..tti:,_:·s in noth hus ntasb::-r nnd bL~s 0h)v(""
r(·f':-1E:~(S
r,-_} J/{)
'fh~? L1\NC·E

t.hP: >.H c:·~.i(,

hti!> for data transf1:rn.
bus ~ja\-~e n-:!(r(5e, t.hf!'

reQuire 1f3·bit If() nnd
network mterfact'
ildch-t.;~s ~p.:_·;~·~e of tht~ \'1\_.Xrnat~:: ;.vnrkst-1•3:.t_i_-a)n
car1 c~:n.1~(' c.xtrtj I/() <:--i.'&it ~t~ttt!'s.

d~-1~;; _ cDrr-n:1a.~1d~ ~-1:~1<.~ p;,_r~H;!~~t~:;;1-s to .und
\1 /\}~!~1.::j_L~-· \-~'iJ~-kst.:1tI(..!~-1 .Stjpnf.~r-'~s

frorn jY1a~~1 s~,;sh!n1. mf:n10~.'"y, "fhe

brrt-h J(~·hi.t .and

rJ~Jt, th(~

V/1i.:'{nJot-c
1r:tert~cn Si.1pport~.

unl5.. sync!l;·onrni:J
of

f(:,·;:-n}~:i I)~Ylf;_ tr~~n~;fr;__-J-·'..;; ~~r ~~h(~ rato

TLie r:-:_·::t:,-~'i.)e:k h.;.1rdivare v."~~ri.::~ v,-·.it!·1 ~t:f;H,J;·1rcl S\-''?Jt-r:rn ·f11~Hi1.:rv .n.::~irtc~_<Jt -~~n tt·ie
V_/,,XLl~.it>} f ·pt~ ~n-;)d:1l~.::, ~.:nd ·.,.vitb the t/j\·x:rnBt~ rEt~r:torv on::i~:1!1 ]nI_:i-Jt-~d !n thf'·
;"«:·:;r~:--;;~:if;tici~ !119~I~ b·:...~~: ;\..::-{:f::S~t~ t::; g~bH- rnen-r.ory :n the Vi\.X__n1;1~,e
h~)X ~ire nnt,
b:·,r the ni::tvvr):r ~ hnt-dvNtrc. }"f the rnernnry
the ;1~~t'\V(;irk t-~,,}:·d\-v.;:"1.~··-:i
third pa.rt_y ttLhi~. I.l':ternc.r_y ;n the
!.;J-.. f:a!~:~~I_;c ~~1:;7>::_ rnay ~"·'°{;rk

Index
802.'.:l Comp<1tibk mode lB fj

80287 error interrupt li•-151
r,. l

,'\11onialies
keybC'ard prot·esslng l 7-1.1

.\t,SI Uwrader Set 17-74
ANS! functionc;
82i1BA interrupt nmtruller
in.iti.ailzatlon conunt1:nd wo.n::h. 3-~;
in~ti.nHzation sequurtf'i::.~ 3~b

purt.s ~3<5
con:~rn~J.Hd vi:<rrd::~ .~i 1 J

not supported

7~'lH

.:\NS£ suppnn
insidt: V/indntv i 7'" 7D

'\NSLSYS ill-5
C1crHor control. functkms Hi :1
L-!·a~;e f~;n':H·tl~)nH

l f) .. 'l

111 f>
l\«yl.K1ard
tion 1.G- ! ?

IJ<;!fiO keybtJard responses .~ .. ;]
,.;\cti ~,/i:_: !.~)--'C]e

DMA. 1:iJntrtilh.>1 -h1

rt-5.t1didon. -fu.J.1ction
lJ)-8
S<~;t .n1od(· funcdnn l ti-JO

Set

/';,,';\fJh:hr(~~HJGS

co.rn.rnunicatinn.s: f~-1
Addn;ss

ffi.t~·:rrupt .15~-70

D\VIA cuntrolh•r 4-[i

requP;;;i" 18·1':1
seriu1 conur1.unic.ati11ns interfnce

Button position 1 il.:3

Attri.butn codt> 7·6
Avto·initinlizi'

Dl\1A controHer 4-,i

Autnnuitk LED control l'H.OS
Available (HlQl5t interrupt lf>-i.6!.

lrmf;"'.tage
A-.i
(\:dl functi.on for tH~ssion LS-lOr~
~ubroudne5

CEJU-hack

for ctat~1ink

BAChSPACF.
to ubort compose seq:imwe 1l··<':i
B;:ise and c1u·nmt
addre% register 4-7

word

i\ne suite
u:scr tj-8
t-'-~tncei

;ilann hmi·tion 15·1,iH
!unction for session J S·fl7

4-8

Bask interrnpt F•-.1.82

c.ascad(~ rr1ocl~_:i-

Baud rntc; 9- UJ
n1ouse 10-~>.

D J\'l .1\ controller 4·4
C:ase convc:~sion tables H3-29

Beep function d-18

vfrtua[ rrH._rde function

5~Hf1

Character

Bits
IJMA comrnller
write all 4-11
write

(l.Jdf~ 7 .13
ccnn~·~, -i_7,,7~;

cnun1: :-.met.Jun l ':·· JJ 4
patt(:rn 7-D

Block tr.zn1sfer rnode
OMA cnntroll~r 4-3
Boot

DIG!Ti\L hard disk

lnnt
11·74

Buffer ov01.nm
LK250
Bus !'.)-3
l.t3~b!t expansion 2<~
lfJ.bit lHcal z. D
8-~bit

func.titnl J;).J49
l.,/Vr :)e-:;sion .1.H~G7

dJ:v-i~.'.e

2-~~

arbitr~t.inn l3-:~

rnaster rnode l ~3-.-4 0
1.ilt}Ve rn(H-le l~:l~40

aPd strJcturf:t .~~9

2 fodex

Ci\'1.()S
updated :t.J . lO

reacL keybonrd··interface controll.er

CJVIOS RA,M

shutdown byte rend during hard
re-:>•~t H·U

Co<ix tnrnsceiver int.erface J;1<2
(\11or

map functions Jr,.g:;
select:,

COI\J J .lseriHl interrnpt 1 r>-G

COl\12!modem interrupt u;.[l

Combination kevs tfi·lfl'i
break 15-ifn:;"
.
extended selHe;;:t. l fJ·l08
pause 15-108
print screen 15· J. 08
i r; HYi
systern n:quest
systern reset tfl . 107
("omrnands

counter-latch. tlire1H~hannd
counter and speaker fi· 1'?
disable lu;yboard. keyboanlinterfoce rrmtroHer 8-l.2
diskc>ttt; drive cont.roller i J -.H!
en<.Jble keyboard,
interface n.1ntrnHer 8-1.'.'.

incremental sr.noam nvxle 1mousPI
iQ.;J.

interface teBt... keyboard·interfoe1'
cont roller 8· ! 2
invoke self test 1mrmsei I 0-8
cnntrolkr 8+1
m•mse I.table} l 0-2
prompt mndp \rnr.m~ei 1 O<~
mit.put port, keyboard-

intert.ace cuntrulle:· 8·12
re.ad port l,
eontroHtJt- R-12

read port. 2,
controller IJ-13
rettd test
l1Rybn;;irdiniotace eontrolt~r 8-1 ;3
re;.,d-buck, three-cbannd cntwtyr

and

G 1:1

fHO
;,dttest 1'·12
vendor rnserved fundion \mo1isel

to.::>
write port 2 8-18
write status register 8-:t cl
write. kevhoard-interfacc controller·
8-H.l

Comnrnnd and n·sult register sets
diskt3tte drive com.roller 11-20

Comnrnnd codes
disable autorepeat 8-24
disable key scanning and rnstorc
rn defaults 8-28
echo 8·2G
enable autorepeat 8-24
t•nable key scanning 8-28
enter DIGITAL extended scan
code mode 8-2:1
exit DIUITAL extended scan code
n1odc 8-2;1
invalid comnrnnds 8-23
rnnde lock 8·25
mode unlock 8-2;,
LEDs owoff 8-2i:l
LK2f10 lwvboard 8-22
request
id 8-23
resend 8-2fl
t8Sf.TVf•d 8--25, 8~26.

8<·!{l

n·~wt 8-2~)

rest t i<f~ybnard ied 8-·24
1

re>,tore to defaults 8-28
set znitorcpcat defav and rate 8-27
set keyboard led 8-:2 ::5
set keyclick volume 8-24
Cumrn~md

keyb•>nrd-interfoce cuntruller 8-i),
8-"9
Ci:.1n1rnand sta.te

diskette dri.ve eont.rnUer
Cum1nunlcations l 7-G l

connector ;.li.rrrn!s ~J-19
extended seif-te~t luopback test
H!O
full <1synchrmwus para!le! l 'Hl I
fu!l
Modal .1 7 '31
Li\T ~mpport l i G2
Cnn11uunications fonctlo11s
ClearComrnBre<Jk 17-E'.5
ClnseComm J 7-04
EseapeC(mmt Function I 7-G G
FlushCornm 1 7 -G5
(ietCornmError 17-GG
t}etConunEvpntl\lusk l.'1-()f,
<JetConun.State 1 7 ~G5

OpenCornrn 17·6~{
ReDd(~ornnr

7-3, 7"41~ 7...13

Ci•ntrnl

sµeed !ndi<:;1tc•r 9-17
spet:;d S(dect. ~~~ 1 7
Control WQrd ,.,,,..,,,,,,~, G-l l

ContrnHer
functions J 3 "2
keyhoar<l-interfr>.<'e 8· 1

(:o\111ter
('ounter·1atr'.h l~Ornrr::snd

t!-uve-chamwl counter and spe<ilffr
G-1 :?.

17-G4

Set(~rnnrnBrcak

n:g-ister B 7-4:\

17 ~-6ff

SetCommEvent~. fa.sk

I. 7·G C·
SetCmmnStMe 17-<)c:·
Transn1itCumrnChar l 7·-(H
VhiteCc•mm 17 !J:l
(~on1pose :seq_uencc0

1fi .. 2:1 . .17""4

! 7-G

defa.ult set 17-5
h,~ndling 17~4

bO\V

poEntt.t taLiln
f0rrnat lb .. }4
use 1.tJ· :.~4

tnu:slation t;:_lt:;l~:~
forrnBt L6-.2:t
llS~-~ i fi-2 4
17~G

1.4-·l 1

C-On$ole. SI-'r\.rer

Const<uJ.t va.l.ues
D MA ;crmtr,:iiler
exv.rnpJe 4-1-:~
Control l':mel l 7-6
('.ontrP~ rr:gisti_~r

11 <~

A. 7-4.l

CHT Controller 7-:3
C RTC '""~"~ ...

Jnde:Y 7~~::J
reg-b~ter RO

7 .. 28
7 -i;8
Hl (l 7 ;33

rt--~_gi~~b}r ft~

/:H
FU 2 7-:J4
j{ 1:1 i -::H
Rl 4 l-'.35
Hl f~ 7<H!
H [(} 7-~~ (i
HJ 7-:i fi
rU 7-29

R:-l 7--2}3
HA 7-:10
H,; 7.. 3{)
Rn "HJ l
B.7 7.,81
RB kl
H.9 '7<Fl

Ctrl and Alt
Del
used for soft r1ccset 14-12
with Home
for diagnostirs
i·HO
Cursnr comrol fonrtion!l 10·6
interface
Custum LAT
Ii·6G
12·8
12~8

.DEF files l7·10, 17·72

:n for LAT J 8·5G
Data
conunl!er 13.:3
link interface J 3-1
stn1ctures <itTessed
U<l
tnmsfor i'.1·40

hlitiaiization 18-1.fi

MOP start and send syst.em ID
l."Hi)

l\IOP stop

8·45

network boot request l8-~3G
open a port.al 18·17
read clJannl'Jl status 18-2 7
rear! ci:nmtern 18<!2
read DE:Cparm address J8<HJ
read portal. li.~t. 18·2H
n'quest tnrnsmit bntfor 1 tl.·26
set DECparm
address
18·40

Cylinder mmi(it;r

bigb
low

disable a channel J 8<18
di.sable multicast addre~s J 8-22
enable a channel 18-:n
enable m\.1.ltinist. address 18-:n
external loopback 18-·:!l

trnnsrnlt. _!.H-2:1
0'\.'(l:I'"V'}e\V

J8 .. ~:)

panmwters l. 8· 16

LANCE

Data exchange for LXr 18·f>8
Dat>.l registers 7·38, lH1, 12.;i

Dat11 stn1ctun1s
DMA <'ontrnHer
prngramming ex.mnple 4·17

Data tr;msfors
lHVl/\ controller 4·4
rate
l l·fi

port driver 18·fi
program <example I 8·46·
rnad portal status J 8·::10
receivt· 18·10
return cudes 18-12
transmit l8-H)
user call-har:k routines 18-8

Date nnd time; stn.irt:ure 11.J-:'!, 11>·4
Hl-24. 17·4
how
Deal.locate buffer for datlink 18-2H
DEC pri.vatc R.<\l\'1
powcrup test cheeks l 4-8
dcdunccidd

8· l 20

Dt1rngrams 18-U.:~
defined 18-8:)

dcdunr:cherk LR· l HI

Datatlnk communication bkwk IDCB)
18·7
funr·tions 18··1 l
close a portal 18·20
dea!lorate buffer 18·2fi

det'fnneddnume 18 .. J. 22

dff.lur,,:delall 18 -128
decfuneddnum 18-J '.! !
decfoni:readindcx 18-1'2.fl

fodPX

IHCfTAL
ftH1{~tinn

De;:GetKb<lCoi.HHtT J 7-8
DECri~:t DOS i>l?S!'tJ)n level lptcrfar:;o
j .~-1

c hPck tor· sessiou l >3~ 19

hard dfok boot block l fi-LH
12-·~!fi

iDpur

ses"iion cnnt.ri•l block i.DSCB)
18-bf), 18-88
:-;;es.sion functions 18-118
DIClfl',\L extt>n<led fond.ioris
t>:>~Lendx.~d rodes rn1d iunctfrJn:::

' :-,_ ! 1 !!

DecSetKC!ickVol ; 7-7
DecSetLrwkState 17-H
necSerNumiocklV!ode

7-IO

DECVV !N. H .i 7-85

1J1(.t rT/\.L cx.r:ensiun fnnctions
P.hurac-u:~·t' ,~01__u1t l 5- J 4
c.>:tcnd\;d rnnd.e 1 fi- t 7
key nnt3:'.'lc.<tbon. 1 tl 11 l
buffer l frJ lr:i

Pntr_y

18-12::
cx1try pJv-en H!)dc nur.1.JJoF:t rot
si~ss.\on J.8~3 2]

na!H('.) fo:r se~~si~)n

18·- J 02

nodf~ ,,1x:tries fo~ se~~inn

fC;Cjl.iCSt

18-1 ~:6

IJernand trnn~f't:-;r n1ode
f} ·~,l ~\ oJn_troHcr 4<~

rft~~.Y on

t.in1Pour error 15 .. ~~}

15140
::·et.urn I.J f(}!']. /\.L
1

'.VOYd

fh~urno;i;;e conunand 1:~·2.J

[ G- U!J

sii:::n_d break
:_.end to

fi .. 84

15-119

I)Jf·; rI A L t.:xten~~u1·1
t:o::dc .~ ~~-1]2
1

!.i'.le-_1n{)l'.':f s"iZ{:d

J -:i -l.<J

boot~~r.J ap 1~;,. ~ 3.:l

i:Jf'ElI area 1H;t1vnr ~:: r.nn.r-roJk~r

Diagnostics
e;(tt:nc~t:.d s~if-test

J 4,_JO

har<l reset i_ 4~ 1. :. ;

t,10vvcrup tf~st 1-.t~ 1-

11ANCE> l fi-1 J9
DirL"(:t rric:ruu!-.Y ;·:tcces.~ (:ff:.d Li\f~f~B
l ~~ q

14-:~

processor bnard t~?sl-~~ t_ ..i ~ "~
HOM ! 4-1. l .i-8
Hflf\:I e:~.te.nderi st.-tf<:e~t 1·i-.l.0
soft reset 14~ l. 2

Dl;,ahk
;".'11irort-:>pf!t:lt keyboatd~intt-:;rfnce ·::on-

t.!'oijer co~11n1a11d cnd(·':S j..,-24
ch~nnci

ft-,r dat~1link J.X-~18
a,nd r~:stnre tc•

pwgramrning example l l ·27

defaults 8-211

cnrmnand 8-12
multicast address for datalink

Disk inputioutput U/O! int.errupt
hard disk f'nrirs lfj-40
!.1Brd disk fund.ions H>·-10
hiffd disk param.i-:ter tablPs 15-4 I
Disk parameters H}· l '1

recalibrntc ll-2G
11-24
si~<111 high 0r equal 11-2 5

'lf'<Ui equal

scan low or equal i 1-2&

Diskette
t~rror~

seek 11·27
sense drive st.flt.us t 1-27
sP.nse interrupt statuB ll<ZG
specify l .l-2G

i__f)-f)9
functinns 1 ~:;~f)q
p:irameter tab!es J 6-fifl

interrnpt 16-14a

writ~' data

Disket.te drive contrnlier
l l ·t\

l l-21

write deleted data l L 22
1 J~2
m.suH state u . 20

11-:20

ref;ult stat1~

command register 11 7
cornnrn.nd st:; t.l~ 11-18

invalid commands U -20
SC 1I-lG
:srt:hut. 11-.14

commands 1 l··l!.J
control register l 1~a

star.us reg·ister 0 J 1··9

D 11-17
nat.l'i transfer rote
DMA m.ode 11·1
DTL ll.·Hi
EOT l l·l.G

H-fi

t:xecutiun state 11-20
oxrended self-test !oophack test
]4.JO

status r·egist.er I l l-1 U
2 U ·12
stat.us register a 11- rn
STP 11-17

status

Diskctres
ex.tended self-test use of i.t-1.0
Di<.:patchM essage l7 -4

Display

l. lB
H U-Ui

GPL

on VAXrnat.e 17-n

head/u.nit select
hltrnd 1 l · lfJ
internal rei;iRters I 1 ·7
~nHin status

n 1H»

ll-8

lJ 4

N 11~1{)
NCN H-17
l 1 · l8

processor 7 <l
Divisor latches 9-15
DLL.EXE 18-fi

dll do!>e 18-20
dll deal.locate 18·26
dll ,_disable·- r.han 18-38
dH disabi<''

18·22

fodex

4-·~S

reqltt3<-;;t

tran&fer rn.cr:h? 4~3

sn:l tns ~1~ '"-~

[i1\'1A...n-~od-.: 1.J-1

Echo

[(?_:JJ)k'

g.2 .-·J
for d;Jtnlillk 1s-::fi

0.U to~::: pf:' at

th~1nnel

basi:~ and CGrrcnt \Vrtrd re~rist.ct

bk,ck tr-ansfBr rn.odc- ~<1
cas(~;n:it.: rnode 4-4
~!~~~

cnrn rr1Hnd

4'°8

1B 2 .~
E-t:ah1.c/di~£"1hl~
~:~~n r h~H ai~ter

t.iOE f ()~:3{}

d.a't.-:t trDH':ff(;f 4·A
dernal!.d tr8.ns fer n.1f)de 4-~
Id~e

4.<3

ruodes ond rBstrk.tions •f-i
open1.ti1);1 4-2

pri:1dti.c:3 4~5

progr.rnn1nJL1g
4-15
data s:nici.Hn's ~J .. J7
disabling [lfvJ/\ cb;;HuH~! 4-2:·?
iniUaiizing 4-18
opening DMA di:wne! l 1 9

LH£C i\todc 7~ 7H
.Dl(a1'AL eztended ~cfHi eodE

lrnrdw;ire l.!iitializntion I '~-10
hori2r)nr,at bar 14-J. 0
luopbat'.k te~t
on cttn1nturdcnt..ions 14- 1 0
on tnou~e he:nal ports l 4~ 10
(lfl
! 4~ .l 0

C~R-C hi:~ i:~-;i

i 3~:1

s_vnc 9att-ern ] ~~<1
trt:tnsrnissi~)n .1})-8

1nernnr.Y sized ~ /i-10
real· Lime dock I 4-J 0

.[xect;.te cor1troU(•.r iuternnl
nostics· b.J11ctin.n .!.f1~!l(i

-..·laf-;~) fa~-,~-1C8S l4~J.O

l.841

Execution statr·
di~sket.te drivt: cr.1r1tro}let J 1-2(.1
L,,:,t

f)t:(· ~/ic•dt:

1 ;~7G

rHtH'TAL exte:-1ded scar1 c(1dt:
ruode 3~2:)
bn:o::
bus t.'.onne.ctors

fih~ qtructure

.LCOU NTRY l 0·27

Firrr1Y\'are

2·10

t'f}'Of C(Hif~S 1.4.~8
(~rror

Vt.1h.1cS l_<-1~8
cxtendi:d s1~lf·t1,c"!b; 14-U)
!wrizomid uar J 4-H..14·10
1n-itih.liz;1tion pr-,occtlo1·e 14~8
HOM. BIOS and l 4·8

Ex.f,f;ruled
('UdE:5 and ftHlCt}011S J ~'~~ l -i fi
rnode fun ct.ion 1t)--'/7

scan •:ode mode 17·2
-functions
Extended
ct•t!es
c•nter DEC n1ntk~ 7 · 7 (i
exit DEC mode l7·7G
E:xwmled beyboard functions lnor.

z;;e~.f--tPsts t4~8

F'b:,ed
f) !\·i /\ cr.•ntrolkr
disk

:..:;uj}p{1rtr·d~

F!uw n.r1nroi for LAT 18·f)$\

'-~-h.c;;f<lct:er count· t 7 ~ 77
17~7H

1·i-77
l.7 77

for

request keyboard id 1 .7g
.Extended se.lf--tc~t
C.'.VIOS

FONT 1(;.JZ,

diskette drive controller l.J·l.0
double-sided. hig:hcintensity disks
U'.,cd

\4·1fJ

Fnnt fiJt, structure
VOJ\:T.COl\I 1G·l7

UHi\lTABLCOM Hl-18

fH;xt L:\_'r service nar-ne J f'.·-·'l"O

st11.tw. for LAT 1S»J5
7--9
<"'.olor rn:ap ::F1ppt\1t f1H~Ft:inn 1.fi,~31
functions 1. t~<i 1

( ~r:-tLatSer\.'.·ice 1 7""''! l
{;c~tLatSt~·t~.1[;

FO!\T C0!\1
a"ff1;:;-·t·t ou i( LY B (~(ft Iv~! 16 l (~
;~n~ect on SCllt1-,.E}~E Hi·lt}
fc~nt file

J--; .. (~f!

17·4

(,RAFTABL HklG

strt.;cttffr• t6~ i 7

GitAFT;\BL.COI\I

tont fi~e structure 16 18

lG 1H
Fonn;;t tfi::.Ck .l f>-bfi

•. ~i1atacr.et t..:::~}:iJe
1F.) 1. 4.fi
c:!c~ri(>f: ir:t·rn.--fa1:c- l 7-2

('OrG1Eand 12~ 1 ~i

:unctior ~ 6-4 7
rE:..;.k~~:tt:1:} dr.ive ec~1t;-ufk,r

forlni;lt ?.Dt~x:1nry ~Ttaps 7~10

"''-'t:-J l J 2•i

::T1>-id~~

F'un.cti("Jnnl

7- J 0

F:..n;,fhon~

d<.et.;olink liH.1

LAT l S-•;4
char{H:·tt:(".~

H11rd di,;k
ix101, blor:k DK>rL".L Hi-1)4
, ,,,_;fl l
~)<.~ra:nt~tet tahies
.15-14G

+-: Jnt g

buffer_,~ ~6
:~es::-;ic,J:

1 ~ .9 J

fJtrrrr/:L,-~~pecific

J d~ 1 8

-el:rtraf: t>t?-rs iii h

buffer

support :_er d:-uunpie pt Jg-r.arns
/~.~ J. 8
(~()!

1.7-2

c:·rh..i.t~ r-~1c1cr.i~ (!

f.-;~

curn:.•nt. ~:Ld.E-~ a_GJJ thr~e fcir S r"' 1H
1

I\1S-[Jf!S OEf\.'! N:..1nJ.hcr Function
1 F•

~'!

l~~-'~-J

r1-:.~~;e:: h.t11{~ i:i[)n. l fi--Ci ~3
type.'~ l.G~ l ;·J

i:llt 2rnrrre srat-t1:S -·"'-· _,•.....
rCJ:.{istt;r 12 .. J0
1

cr:rru~1and

torm»t track command l2-J 7

example .i2·27
t2· t:\
cnmm;ind 1~~ ( :J

St'Ctor COnlffliJHtl

12· I

restore c1.inmrnnd 12-1 l
SDH
l.'.?-9
sec.tor s:·ount·
J 2 .. t
sector interkuve l 2-1.8

!I()

v,·vit stat~s i.ntrodnced
LANCE 18-40

fCONT·Dl'l'.EXl"., 17·88
k:vns

sector m1rnbcr
Meck command 1

l<lie
D l\'l ,1, ,-,mn-11Her 4 :1

13·-:L l~i~·~
J:l 40

JEEE 802.:)

l ~~.;

vvritc scctr:ir cnnln:anli 12·1.5

}L:n-·d r(~~, ct .f. 4 1 -'·~
causes J I- J ;,~
shutdu-..vn
1-Ian.t;:\'.are

lllogical
ln--servic.(\
lndude fi!es
LK~~f>O

butfer tontrol "itnJct:ure A_. . 1 J
~t··uci.urn declanition A-8

•)Xtel1df'cd 5cl f-1-.2st 14· l I)
14-·A
onP~shot G-4
sturting' with Ctrl!Alt/Dd l 4-12
sv.<;tern tests at startup .Uk!
~ trobc f;- ~l

Harrhval'f' interrupts
H0287 error 16·1.fil
avaibble HRQlil) lf.1· lf1l
dock tick Hl-f1
COMLserial Hi-0
COl\'121rrwdern 16-G

di;;;k J;;.7
lwrd disk Jt,.J;::,1
keyboard .l fl-<)
local awa network ccmtrolle•
1LANCEi
; ;.149

fncxernental strearn rnode cornr!1e.n.d
lO<t

lndusrr1r-stai1dard fu11.ctfons
vi.rtunl ruode 10·9G
cancel n'Larrn 1fi~l40
do"F device I :Hrn
ciC\'iCL'. is
d_iski::~ttf~
(:rror~~

I b~f,H

funrtions

Lf~~fiH

pararneter rables J G~r~~i
t~nnb.lc/disable ? :JG ch~·ir.nctcr
font .J (1.;30
f·i<:~ecute cont.roller internal
no~t-ic.s

1 f)~t~H

muuf!c port .I 5· l ~iO

font H:\M aml ci:-lnr map ;c;uppnrt.

nonrnaskable
lG-:i 10-76
rnal-tirne clock 15 l 48

forn:at

OAH 16-148

i__

f~ ~::~ i

trark 1O·"-i'i J.G-66
hnrd disk n ..':~"!et 1 r.--~~~:3
inirfolize

Index

l l

cntirP disk ~1Lbsvsttirn f),..42
print.er _;_ ~-;. . .126
inter1 .Jpt: z··ornp!et.ion handJi:-~r 1 fi-·-r-}S

real··tinw ciod< t)-L18
n:.n. date lf,. J :CJ9
..::'v:~tt.~rn f'lofk l~:!i~l~H;
tc-tn'":dr1.Jdnn J ~)~90

}:Jj::_H;l "{ !~~ ~ i)~j

,v·c:d(r f.'n.e t)t n1ote disk ~Actocs

m""'"·''"" Sti-ite lf;·! i0
St~itHS ~ fi-)

fJn

rn(rvt: i> !:J:ock ~Jf rnenlory
crpeu devir~e J fi-89

J Z>-.H}
L)-~:!·_3,

!_;-f;(}

2~:!6

tJnc· fJl- tn<~rf~ d it~k sef..tr1r s 1~-~-~44
(Jnc o~- nv.fff: t_:r::n:.'.k se~~tors: 1.fi~rJ:-5
pL~:cf 1 ~~~ ~~4
r~~-aI~tlrr:.c-~ ckv.°.k l fr· l :.~--;
ref7<.1hhr~-~.te driv~j .: 5-b:~
tt'.?.c-clve c.h-'3:1fBCt(ff !. ;)- "/ ,.~

1)1(1 fT,;:\L e"::..tensions

ret-Lrn
purt t;t~~tn~ 15-7 !_~

stat11...--: 1~1--G8
z~ur ct~nt dr~... ·e p-~_u an1c.ter0

fo~"rr~Dt

st:-ttus (qJe ~xf l,;,ist 1/f} teq'.Jest
~ f!-.-J..3. 15 G2

H\/;·1~l:·tbte \Jfl~i~] ~)} 1~~1·151

,-f"~~:.:J:l'?ttt_: pl:E :·:i.rn.~tt:·r L.'.ti:d~~-s

l fr· t43

hard disk ]
hard disl.;: pDi'BJlhJter G-tb!<~s
brt.:;a k~ 1 f~-· l 41

B}'Stern reqt:est

;;.;.·t

GitJdia t_ypn Ior

'l :~~-G~-)

t :-}-;;.~

drive t;yp>:.? 15~;~,.7. 1:;-f,i'7
prf.:F.er st.at:Es f_}. L?.G
rrr r· date 1 ;5- l3H

:';(~r\:ict'

h~:·t (iri\"'e and

pr.ir~t

;:.(reFn 1,),.,4

l'\.'icd

:-(-:tid
t:un,eir pftsiti!°JU 1 ~}- ~ ~·)
(:ur.s:(1i type J C1-- 1. 2

ntige If.-I(;

l :.;

Index

rc:al~-ti.nii~!- cloc.k

redirec::. :u

fi-1 G
1.~-~-l.48

O;\fl l.b--i.~h

revecwr of inh~rnipt: laH 16-145
RTC alarm. 16-148
si-dal piintH port 5·1b0
timer tick JG-141
video p~,ranH.~tr::rs J 5~142
Imlu<>try-st:omdard interruprs with
DlG!TAL t'~~ten<:;kms

asynchronmis communication.,
5-ifl
uissette inpnt.,'ouqmt I 5-x!{
clock t1ck l 5-G
COM Lserial ! fH3
C0'.\112/modem 156

disk.

OJ<)} 1.6<18

g·raphit:'.S (~har:H.~t.er table
Jf,l4f>
kevboard 1Ci-Ci
keybo.::lrd
l 6-101
p!"int.pr outpm: 15-123
tir'{t(-Uf·da"y .l [1- l ;1f1

l nitia!i z~ttion for dnta1h~J~ l 8-.1 ~)

l G- G~
dt.{\'C ch.:1.r-actedsUc5

»ntfr•) riisk

1 fa-,!!J
i f;-1'.;

Internal
di<:kette dri\'e contrnli0r
c J J-:~:;
cmnrnantl 11 ·7
fJ l l - 1.7
DTL i l.-Hi

EOT 1Hn
(<PL Ll-16
H .l l-15
hPmi!tmiL select l l-8

hltind 11-15
N 1 f..,J.(;
NCN 11-17
PCN U l.'7

n 11-u,
SC 1 J 16

srb'hut 1 I l 4
status
st;itus

U l.1-~I
1.Ll.O

statuo. regiswr 2 11 ·12
status
STP l lTI
t nternat-inu.ai support
FOt..:T G· lil

GR!\FTA.BL HHH
lntenupt

lh1~:: ~tabJs D-10
n:odt'm s:tntt1s 9-10

•m terminai !Oui.rnt
;\NS!SYS l\J-f,
upt.1011.s, e~·~tli;-~nd.r•d self-t-est. L~·--10
ll\'T I JH support 1.7-8'.?
l NT l !Hf :o;uppnrt J 7 -82

thn!e·channd counter and
•,rn·'"""'~ mode {l4
[ni.ernipt
'2/\ 1_8-8~3. 18-!ll
Gi\ 1.S-H4

6U 18-1 l

1!\J'f 1 td-1 suppurt J 7'··B:~
!11terftJ{'t~

rnor lit.or 7 ,4 ·!
test: cornrn.~:tnd,

t:nntroHer H- 2

21H
furn:tion :JOH IH-:l
fmiction '.JS H 1.G<.:!

lntPrrupr

~~dd.n;~js n1v_p ;? fl
contro1lf'r

H· 4

Lndftff tnteriacr;,~ g_ 1
funct.ion 1f)~1. t [)

·hufb:-~r

cnn.!;nJl~erso

rnt-~.::~sH._g"C;':; .I ·z ~ 12
Functi1rr1 1f:}-J09
inptii'. inr,•:'.t.nipt J :)-10 !
_;x1t<::::tfact:.· ii ne~~ 8- i i)

3-2 i

IL1i::, mqio i.:i-40

inp1.~t.-

~·i· l .S

t H-t :~~

tuu~:tion

co1iti·ol.1er co-'Tlrnnnd <'-odes 8 :~:J

ta.yotlt
1-;F~

Ll\2:\(i 15- Hi'.3

J ls ;_ ·7 ~-:b

:ru:ip file struc.turt~ LG-Ji)
n·1-·Jp tables
(T(~d.d:1g I G· ~2 ~

~.-. !S-\Vi:ndov1'S t::xr'l~nsl.{>ns

anon1~tUc5;

1 '7-;--:~
l. 7~1.1

scan (.Udr::·'.") .1.~;--104
user
sratt:: tnnc:tio1_1. lf»,-1 t.O
st.l:itus fn:1c.tion lfr· !.On

1 ?~n

t-<:1h!c pnii:ters h.n1ctlon .1 r--,-120

l7--g

n>.1r>1r:a:,ion e~:111bk"d

F.c_v
l 5~11 ~-~

('.()!nbin.J:-.ions

7-7

f},~~t:Sct(_~:u:;-1p(JSeSt;:ttt:· ! -~~~fJ

J.G-10'~

f)~~(·:s~.:tI.<ockState ,~ 7-6

i~terSi;:~\Tucclierkiv1ode

l ;~- l Jfi

f;1~.t.er.ch~d -st·~If~t.es~.

l)c 1cSct,(_1 !if~k\'01

pnu.sf~ .:.t)-Ji)f.;

r;,:--c.urn

1 '7~10
l 7 ,.()
1- i" ~G

17 G

E_rc--·/I~.c·()\,~

1~~~;~-:

Lo;~.' ~d"fc;~::1.(~d

by f'{)N·r_( ()\J
i

,"':;

: •-"': ·} .,

u·~-} G

Kt,vbnanJ-.i.ntcl'face controller 8·· l
command b:vte bit detinitiuns 8-lO

to the CPll fH
to the keyboard 8-1

cnrn1~13n{1 codes

port. bit definitions i-\-;{
pulse output port !{-J~i
tTad pon l R- l'.'.
rt~11d. pt1rt-. ~1 B· 1:3
rNid tesl inputs 8- HI
selft.tost 8- !2
status n·gistcr 8-G
write port 2 8-13
write stat.u<; register 8-1:-1

Oisabh.;a autorepe{_1t 8-24

disable
scanning and restore:
tu defoults 8 ·28
echo g . '.?,f)
enable autorepeat 8 24
enahJt!
~~-:anning 8-.:J.8
onter [ll{JIT:\L C}~LendeU scan
cud•~ mode 8<!::1

exit. DIGITAL extended scan
code niode 8<.:':3

inv<ilid r:ommands 8 :n
keybmird 1nod1:; lork 8-2Li

keyhoard rn.ode unlwk 8-:~G
Lf:Ds on/off 8 ~!6
request keyh•mrd id 82;5

l<eypad

edit 17·8
numHi.c t7-J
f\eys.

Nurnluck l 7-:J.
under JvJS.~\Vind(nil",rB J7-:}

rt~ht.~rvt>d

re~cnd 8~~9

re~erved Jl-26. 8-.2ll~ 8~:!n

re£-~et 8-29

reset keybnard led 8<~4
n'stme w defonlt;; 8-'.!G
set autor·epeat delay and rate

COfilHldnd~ 8~n

LANCE
broadcast f1ddress 1.'.1.-:z::~
buffer d•:scriptiws. see LANC.F
mes.;;ag:e- descriptorn J:.3··27
huffl~r rnHnr~gen1ent 1:.i~j 7
ront.roJ nnd 7:ttatus regl~ters 13<3
(i:.)ntru!

CH.C 1;1 .. 22

csrrn i:H>. rn-rL .U·7. LJ-8
disable keyboard 8 12
enable keyboard 8-12
Prrnr handling 8~ 14
interface u.>st 8-12
responses
8-:)J

hnifer 1w1ernm B<lO
echo 8-30
r~}lf'.t4S€ pre-Hx 8--3 1
:-e;,;cnd 8-'1l
sdf-t.l'st. failure 5)-:l J
se!f~teBt SU(CC8S 8<JO
inter rw::i::

1:.Lrn

CSHO-CSHJ U-S
CSJU Li-4. i:.Hi UH!. Ui-7. 13-U
CSR'.' LH. 1:1-S. nE;, 18-7. LH-±
CSH;J Lt ·I, l:IG 1:3·7. 1:3-16

CSRs LHl
dat.<1 buffers 1.a<L c1 . J
datn r:ha_ini.ng lJ--27
data st.rucrnrns J::l-a
descriptor enky ia-27
18-4
Ethnnd dati;I stream. J'.3 :n
initializBtion block 1'.i<l. B·lH

base i:H.1d:~ess 18-}H
rnnd.e 1 :~ .. 1 ~

addre';'j filter fitid l:3-'.'2
;;;dtlncs'' mo sk Ll :I
n1f:ss~~_ge

1.-i."::~7

rnodo of onuratiun 1 :~-4
~-1ddres:-2 field l a-1 9
addTf,;s ;JH1SK l:l·'f
J.:3-'.!7
progtf'n1~ning J:l-::l
Sf.:QUf;jjCt~

l :)~4

recuive and ix~.HJ.srnit"
rings 13,;(. -i;_~-4~ 8~2g
Joca·tion of 1_:j-."'t
nu1T~')t:r of e·ntru~~~ :i :3-4

custo1n appJJcat-i.{:.<n. interfact; l -; . (JG
d:tta e;{f·ha1ige 18 .. fi8
fiovi.' cnnt.ro! 1H·-fi8
functjotH1 18--':14
close sei.;:Binn lH H7
µ:et n.ext ser'·yice· n~n1c 18,70
get Stf~t"US I8-G5

open ~-f~:;sio.n l.8-t30
read data ; 8-"f38
send bn:~ik signaJ 18 .. 72
send dat~j t B·fl9
~~r-rvic0 tt1hle n::~H-Jt 18~7.1
nver"i., i(:~~v..- 1 g .. ,~"4
pr OATH ft! C~'{arnp]fl J 8··7 a
~r~rvice d~rer:tnr_y 1 f.~--:-.G
~c~sinn f.:outxo1 b-lock J8 . . fi-!j
se~~lc•n ~L-u-t 1s-c)·7
:.;;t-ssion stat1ts 'lvord I 8-6~!

rr:-'ct:frve !TiC~E::a~f!~ Gesctiptnr ; .

rrqcd. 1 ~:l-;jO, 13<.:7

dEd<-~-

p- ;?'~. l ,~j 'L j ~~~f}

t :)~32

H!\HY:! .1 '.kl!'·
staLci<'

1:1 :.;

~-; G7
ncadf... ~J'" ~ 7 ·t.:~8

t_.ipi:~ci._,:<

:).--a5

~rIV1J):

'T~vUJ~~

_;3 <3 7

(f(.:t,[,;;~.S(-':::rv~~:e -~ ~1 -7'!

(;::~i.LDt:~r:;;t. us ~- '7-6!1

t- :-1nsr~·t_;t
d'f;~::.ri~EGr
r:~.:,..~::~sa~~Y:

Li\~~~C:E: ~ St.'':C. lA)~-~2~ _~-\r::-<.i

·: :J-!~7

!'..;et'\vork

f'.Gn((fiUer J ~i~~~

LC'() u l\rf.Fi "'{ l (~<rI
fBi::~ .·.~t.~.'ltctr::rt~

J.• E [;.~ .1 7

,d) g\vhch u~; :3 ;7~
iG ~;.vir:c.t1 18- ;:~G

rJutoui,:::.tic cu:1tn'il l ~~i 08

r-uiur indh~ati_fn1s _;_ 4--8

/H. :-;-y.,'it/_-h 13-GG

caH-hack rol1ti1H~ 18~58
a f:i(:-:ssic;n 1S~f~8
18-:)5G

co~n_:r:r;_r!nd lice

1f.i--<.:;7

l 8-.HO

j)~)\Yf'Tt!p t.~:..~-!~ 14~8

{/() bozlrd t 4-~8
HH::;:riG(y 1.Joard

t-.A--B

prnc,Jssor hoard J 4-"l

»up ported .l 7-4
LEDs on/off
keybo~1rd·intertace cerntroUer co1n~

n){-1nd codes 8~26

Line

]V[ain status
~vI aint.erianct~ <~pr:r<itions

J_ ,.f{2fi0
cornrncind (J)fies 8-·22

prnn:wot
st~lf

(on sole st:.:.rvcr

13.. 4 2

jonp sf::rvif.:e& 18~42

net\vnrk tHJnt request l 8r48
ren1ot.e rea.d coun!-.t;r~ JJ,r4~1

·~-untr-ol func.Ucn1~' d~-·8

error ltDndJing 8<3 -:
serhLI c-onnn. dr~\)~ce!:.t r.o

Li\T servi.•.:es J ·rg2
charact•::r posit.ion 7-"I
2-4

res ptHl~t;& g-:3 0
nc.kno1<vJedge 8-:~ l
buffer overrtJn 8<"Hl

etho 8-;:~o
YcJe~1se

durmg E'xtemled seif·te:,;t 14· HI
.,vithout, initializing 1'·1-1'.~~

S-:11

r<:scnd s~ ;j;,

use l n. real rnode :'i 4-~R

seH-t.c.s';· f~JUure 8<31
~11.:l:.. t1:;f.. t. SUtCBSS S~:~O

scan code>l 8-E•
P.nd
vahws 8-17
tninslated out not used S-~n
;;ystem povvenrp 8- ~~
translate 1nnde 8---2
R:
•)
lJ.S. and
-.. - •• !

three··channel ecmnter and
G-:~

17 i.2

Loadab.Ie d~:\.··ice driv~n-8i\.NSl.S-~{5

1 G--fJ

? lO·U
l\ lode-dependent vah..~e'3
~e:: r.nrso.r tvne tunrt:ion

\·Todern
nmnfccwr sig:uals ;1-21

lndex

1.7

9-J 7

'!\1Ir)nitor

t,r-::insn1it.
nnd receiv(; ~Juffer 1.0-8
;,'c·ntkH· .rt::served f1;Jl{:tk~n cnrnrnnnd
J"vhn~sc repcirt~

lntcrface

Ibyte l. \ G~""l
,,
oos!tic•n ~hyte ! ()-:}
"'
p1··_isit-ion
:J I ; 0- a
c

1\IOl' 18-42

start ami send ;;y.stcrn lD J8 .. 4r,
~top

.18-4:)

st:::·l-f-t.esr ~b.v·tr· t ! 1 0 f)
:<df-icst
-· I n G t0-7
" ' I 0-7

!v1ouse 10-1, 17~H1.

asynchronous ~f:riaJ iuterf;;1ce t O<~
baurl r~;tx-;s i 0~2. 10-.1.l
1{) <1
1 O<!
C~)lTIP.1\.lr1·ic<ttl~Ofl 1.0-::;
}.Jutton

I\·lS~lJ()S '!)att:~ <tt~J

corrnn.~_nrh; it;fr'llc!

\its Ner<-:ork

dat.-3 l1V1:.t-lS } 0- 2
encode~·s

cornpatibl(' R(';;~inn s~r\~~r._:t;.•:; t g.,f)~J

1 ti~ l

extended se·if-tt:st
seri;_~l po.rt.s 14·· lo
incren1ent.ai st:n~arn rnode cr•rn,-~
rnn nd .l (1-:i
h1\·oke seff-~etd.. cnu1n;.urid

r1n1e S:·xucbJre

hVi_\\H

i~<!-

~?t:B:<~inn ~t~v'.:.)!

interface L:J~ t

lVIS-Vl/indows

t-~n:-~·.v

;.\ ns·;_-rn(Iern i !'} -b5
()f-..:'(n·r( ..i\n~f ]_, 7--GH

progranHni{1g exa.:--nµl(~ !. 0- 1. 4
prornpt 1n.ude con1.n1and L(J--~:t
r£P•lrt°' l (}4
l 0- 7

rtisHbic 1t~~2
for~r~-_!_t ! ;:~.~ 4

rHqu.e&t nJc~t1se

ll}-a

self-test L0-,i
&erial H)terfr:ce
;·nndt
mode
st:=1.t;1s

1 e~no

tTijnsn1it
n;t·~i,-,,:·e buffer l.O~S
SC:f\f22G1 er:h.anc~~d
'"'····-"- ''"~ curnnti.111!.'-'atiK).t1s

interfacf' l (V:. l 0-S

boot r,.:_~quc~t J8<-H;, lR-4:3
hurdiN~1;-··c lnuo.rfa.ce 1 :3 .. !_
intt::rcun:¥;cr~t, C:SR Ll 17

c:sn. L5~t1
f~xtc;"ual ictet(l)Inv.~ct

l ::t-40

port retry funet.km 15· 1 :i l

!/O ports LH1
description J 3 ti
sy~Hr:~~n bu~ interconnect

13-4(1

Net1Nork sofhrnre 10· 1
components !. 8· '.:'.
ch1talink 18-n
nve1~v.te"v

J8 2

CSH l;i40

Nonmask:.1ble

Normal keyboard lunctinns
fotch next character input trorn
kevbo.ard 7.75
r(:turn current shift stat.D!j J 7~ 7G
wst for cbarncl:et ~·vai.bb!e 17-7 ".i

Nnt supporrPd fuiirtJons
support lf'>-\,ll

Parameters
cfok l G I. ·t

Periphernl interrupt 1:ontrol!er
:3·24

Pointer
diskdte p;irnmeter t.ables u;,.J 4;!
grnphirs diameter tabh> pointer
1. [i-! 45

hard disk parameter whles i 5 l4G
viden parameters 1t~,..142
Poll command iJ-17
Port.al
dose 18-<Z l
defiried J8~t~,

n'ad list 18 ::?9
read status lB-30

Nurneri.r:

Numlo•'k
numeric keypad 17--'.\

Pnwerup test 141, 14 ·8
Ll:'.lJs 14-8
H/\\l checks 14-8
self test error codes l4·8, 14· lO
sequence ! 4-1
Print sn:eui 1. G-4

Printer

Open

datalink portal l X.- l 7
device functi·on .l {1· 8H

LAT sE'ssion 18-GG
(J.pe11('~nn1111 17~i33

states
diskette drive mntroHer l.1 18

connt'.ctor s·ig-nHls ~1-20

extended selt-t.f'st loopback test
14-10

tlDl support 17-8::!
our.put interrupt ! 5-12~1

to Host mode C- l 2
:ype function lf.-J.29
Priorities
DMA cont.roller <1-5
rotation :1-1:)

Paralld
bit streanL rrrnverted by LANCE

n-:3

Pruressor board
testing 14-14

Processor nmdes
re:;t mode 1.J-8

Index

d.at.:t :··c.rrun.:•.n<l 11~21
d~;~ta fer Li\~r l. h~(i8
~~~;~ta~h1k counte~·-s

.1 H~:1 :~
:;:;ddre~;~

dule'".-~>rt data cnrr;rr~und
(~2UtHr;J..;

18- Jf;

11. ~·22

·c t·nrnrT_1~nn 11-!:~a

i.8-46

niskettf; l.idvc {·:cTJ~.n::1h~2

f)I\.li\_ u-.:trt.;J:~:~er 4~· J ;-)
-,,_;n:~;t;Jnt ~.:ahu.:;i:, ..:~ !

f:.

di{f:'.;-1 ~trui:Lurr_::s 4-17
f)f.i~/'";,. {_'.l~;).'1.!J<·;l ,:~-,22

~~i:~~·cs;/;n .1.B-1:2::~

LAT

nn.t:. ~.'r ll;ine c.t~.si{ ~;e 0:::.~Jr.~ ~\_;_n(.~t-~.--)~1

f.-7"\

Itl(E i5~0~ _l 0~ _: ~J

.':fBl~t:.1nl(: cl·--:h'k
c~r2(>:_··hannt:J

Ctr1. ;_:·:tr.:~:If-; -·ne_r fi-J n

C1\IfI i82bUi\~ !-)-2~

fu.:ncti.:_}c ·i ~~~~4
;;o:y t
c~:~n1;T1~~.:\ft ~" 1.:-:
:<'-~-' t ... -: -~.;L_.. ~.rn:::~:ld .g<t :.~
~1;:~d-~1s

for :~.:iBt_.2:·~:~1.~.:;

i c;-~ >thr:ir~ ('.)JJCh bJnct-.i_o:·~

Pui::~ :;i~tpi;..

·<yc:l.~··r

i:vr_c!. ='.:{H1_:;;-1~1;_~~J
L;:-:~;; ~:~~~ntro::e·

• -~

,·hck : J!;,:i•.:1 .i.f··, :;G

te5: inpz.~ts '~.·oc:J:T~::F}_d 8~ 1J
~;·ar:o.:~ ·.~(}lTJr~and. .i ~ ~2~1

'.·t{~;·.1d~b;~t~l-:"' ~-:~~:·-'1 ~r . {1nr:

~: h: e·~-c t ~~1~1 ~tei {~<.:.~:n.~cr :."-.1J(l
·~~/SV~'.; :''

p:;~ver-.. p t(:~.;t, .:~}v:_;ck'i

Lh-:3~)

~ fi'.~ -~- 3 7

·i-f.

alarrn
;,. ';.
,..~t.~::r:-~nr.~c ?~~}rn-1

dvt,u

nrnges ;-,-l .l

data

;'i-l 0

:~eek. \.~C1(n111t:H1d

1<27

sense dr.ive status cornrnand l 1--~:7
st:~nsc intt;tT~Jpt statu& con1n.J.a.nd
t 1-2G

int~rrupts

con1rnnnd 11 <:G

f1- l.·t
<.~xs 1n ph~ ~)- l ~-.

J 1-~" !
writ'-' de!P!cd dnto commaud l J-22

'AT.itc data command

c;-4

UAftT !J-'2
disket.ic drive 1;untroller J 1.-2
c~ l: i.r1
cnn tro'. l l-:'i

u 1 l 17

Recalibrate <~ommand
disk.ette d.rhte controner
set~ 11-20

cbu l l. -5
dntr~

transfer r~,ite 11-ti

UTL I_ 1-.1G
COT l 1-lG
Cl PL i J~-16
llil1f}

llt-:r.t:;:i"\.,,f:;

;cuiy tor scs<;ion .l H l ~
b~'fhld('ust, for se~sJon 18-J 17

lH~ad,.·u.nit sele1·~t

1..-S

hlt.:nd l l- l '~

buffer/tra nsl'nittcr
9-'.\

int.ern.:jl l 1"7
rna.in ::;;tH~tus

character fun('tinn J 6~7 4
fnr sr~r;,:.~inn 1X~ I 1 G
for dataiink 18 J (J

\J t l-i. G
:\Ct'< JI 17
PCN 11-17
H i .~ - l'J

-frn· SPS~icin 1A-11 ]

nw;;«age rJ,,~,:riptor, sc;; H.MD

S(~

1a-2!}

1-lb

~;rt/hut j 1_ · 1 ~1

function lfi~'l 27
[ ()-1-18

0 I 1-H
1 11- J (l
'J
L1 .: 2

stru--u~ "'"""'"'"<'>

;-?.-

.11~J8

~TPll-17

:;.:~ts

fnrmat rxack cornmand i. !-::;'4
read data c<HnJnand 1 l-~~ I
read <h-:d.cted dHUl r~ornxnand

read id comin~md i 1-2;1
re;id track •'Omnwnd l J-2:l
recalibn:n.~--~ ct:Hnln<Jnd _t I~~:b
sca1 i
cnnm1 nnd J J -2 4

s.;.::nn

St~.ltuS '"'"'"' .~~

st:an lr.n\' Ot

equ_al J .1-25
I, 1--2b

t~22

DM/•, contrniler 4-':
b;1s~::: anr!. (:urrent kJddres~ 4~r;r
bati(:_ i:n1d r_-qrrent ivord 4,.g
cru1-anand 4~fi
mnche 4-12
remiest 4- ! :1
~t.atus ~l~ l 4
lcrnpurar~;l 4~14

r·n:1hle ~~~4

Index

inte1·rupt idcntifk~ati{~rt 9~G

o.•mm.snd 8·~!
cuntrolli·~r
CO!Ul1H3ll(1

s-r;

dxta ~-r,
starns B-b
line rontrot fL i
1ine stat1Js 9-11
tn(JdeKT~ cnntroJ D~ ~-~
n1c~dent status LL13
receive bl1 ffe.r/tr!ln~;1n~t-t/"'f' ilnld.ing

n-;;
specieJ pllrpo~i~ ~$-1.~
t-11ret:~(~haanel (~{Jt1nt-e~- and !·;pe;Jhr;r

1.:ontroller corn ..
n;dnd r:odes 8-~?S, ~5<!G1 B<Z9
fte<:tei.
for scsmon \ 8··BB

controUer con1~·
:1~t.u1d codes 8~2~1

C{H]J.t'nUer

C(1nnnand_ code~,, 8-:-~4
n1udc t\u1cti(Jrt 1.fi..,_t
pr<WB~j.S!1f 14-1;{

G-3
rn:1 tn)i ti~ 1 l

H.esture tu det~n1Jts

&ystt~-Hl C--H

ir1 b:rface cf1nrr0Her t.f)i'(J-

\.'idco contn1!h~r
colfff ,~;f~let·t 7 ~::t fi

1~·10.nd t:ndeb

rr,int:~·ol

c·ontrol rcg·i.st.e1- n 7-4:3
st.a.tu(.; 7<17 7<-F~
'?i>-rite dn t[i 7 ,,.l H

8-, :Z 8

Hesi:dt ::;uite
dis}-;r·'.1-te driv-e cuntrollvr 1 1~20
Return

R.ele3se prefi-<

Ll<'.'.FO

line sta:t.u.s futh.:don 15_.r;.s
current drive paratnf':t.er:S h.Inctirrrt

Rcn?apping·
ke.vhoard lH".l.H
H£'.lr\(~ 1_;e read 4.:onntcrs

J ~j- :1-.l:_;

18--J

Ht::pr,?ahng i-;cy
fot:';JS ! 7-

Ilequest
iii>.>. D~vl.A ·.::;-cw

rni:-~s1n.it.

lf;#Hf!
c:;r'ive typ<-} functhn1 1.f) fl7~ 1r~-H7

buffer fr,,r dat:-1lin.k tH-2[1

keybonrd id l'i-73
func1-ion 15-1 J.8
(/.1t1tr0Hcr c~\;f~ ~

n1a ;d eodt~~~ f\-28

n1nn~J

Indt-_x

contri)ilf::r cf:irr
cqa_e& 8-2~-~

rn_c-1-:1ory s;.Zl' abnve oT;.(~
fun(~tion tr~,~)~~

1T1Prnory ~izc• irn,ern1pt l rJ~a7
sl..;:itus hmctim1 l5·l '.!i3
HTC da;y hi.nction lD-138
sL:itus code of l-Hst I/fJ rf"rp,__1n~~t
tr,- HJ: l fi-'"·"·L1

Ih~v,:1·tor of intern1p1'

\;JH interrupt:

t ;) l ·-lfl

HOM BIOS cass(,ttt' input/output in·
tcrrupl J 5·88

HOM BIOS
;:;vaitabie llHQJ 'i!
bv.sir: :interrupt lfi~l :-;~1
boots t.rt~ p
l 6~ 1 :) ;~i
clock tlcJ;;:
l f).,;\
Cfl\11 .'!».crial intenvp1 ''d3
C0!\1~hnodern interrupt 1 :} H
,s()ft reset 14~ I 2
firmwr>re diagnostics 2nd 14 8
initia tizBt io-n pror.f!dnrf::

operating systrrn ! 4 ·12
inea! dn.:a neb,\'1Jrk contrnEer
1L:\NCEI interrupt l ~>-l 4P
molls(· port l.nt('rn1p1 J f,. i i"•O
rJtJnr11;1skalJie interrupt. };j.;1, JJ1-?{i
-;rreen interrnpt. J 5· 4
read
inH:rn1pt J ;,.;{(,
rnaJ..tirne clock interrupt. l f>-148
wdired 1o inlerrupt OAH inL,:1·rupt 1;)·"14B

ren1rn n1en1ory sizf~ interrupt
re'vectnr of interrupt 1:31Al interrupt
15
RTC alarrn interrupt I f. -148
St?rinl printer port: lntflrru_pt 1:);150
ROM BIOS 8028'7 t•1·nir

RO!Vl BIOS

initialize
ti:)n lfi.-72

hegin ,·irtnaJ n1ode ·1 5~9(}
clo:;.;e device _l b-89

dc:vicu is busy J [>·98
e.ornpletion handler 15~!)8
sapport. 1 6~9 l
n'ln\!t?: a bloek of inernory t 6-::l3
open dt:;-vJ1·e 1 f:•-8~)
rdnrn DlG!Tt'.\L
·~\·or d J {1-H fJ
ret.t.ifn rnen1ory Rize obo.,fe c1nr·
1 G~H5
S\~rvice systr:1u request key 1 £~~91
~et n \valt intervnl l5~BO
ternlin~!t.itn1

1.5-90

ivait (.no return to user) l G<92
ROM BIOS 1Esk 110 interrupt

i5·:~8

diskette errors l G~fiH
r![skcttr hnwtions lf)-fin
djsket-.te pBran1etf:~r tables .1 ·~~-f}9

excc;iLe cnn.tri:)ller int~rn~d
nosi ics l f;-f;6
form~i1- tr;:ick. l ::;.4 'l' 15-trn

hard dsh
f'iTOf~

-1 f~-40

ftinct.Jons 1{1-40

rararnetrr tables i fi~4. l
reset: h11H.~tion 1 G~6~i
l:1itiai_i1,f:

con1n1L:ni

disi\:ettc subsystern 15~G l
di_·ivt· chaxac:reristics J fi--.j~;

entin' disk

('.at.ions
c>:t(~n(lr~d n'Iode

set 1x~ud rate l ;~)-B 7
set nloden1 controi l fi-8fi
tn1nsn-1.it ch;:ifactcr 15-73

u.>~4~'

lfi-77
port. fuw . ··

retry f1n tirn.eout error 15~~G

r0ad
l b~50
rend one -or rnore di~k sectors let~
.fc!
rensf onr· or n10H~"" track sectors It:,():J

rer:alibr a tP drive } 5-f} f·i

!ndPx

n~turn

drh·e type r 5~:~7, i5-G7

.ceturn ~ratns C{;de ,of k<Bt. Vt)

retruesr l ;~}~.J:), J fj-f;~
seek to sperific
set drive ::i_nd
forn1at .l (is-(HJ

t.e_.,;t drive ready J T:i·-G4
on~_, or n:1nn~ disk sector;~ \ .:·J~

J f;ll·1. .1
1:_~i1
lBH 1f>·I4l
iCH Hi 141
lDJ-i ifi~i42
!.Ell tG-i 4:J
40H fi·l4ii
ilB Hi·l ·!6
HH·l ! (1-l W

,1/\J·l

'j(l .. 14ti:

70f-i J~J-~!•LS
71H L)-148
t:'H i :·1-IA'>
·~vht.(~- kn;.f::;' Tfa~r1-;
v.;rite one or n.arire d ~.sk sef.·tt.H"S l oJ

7:1H 1;-; .. ; ;)G
~/4ll

lG~J.f.l)

7fd·{ ] f;)~'l 5 J

;,,vrite C.HH; {J;_~ rnc•re tnH'k se('turs

errors ~- ;'r-.f;9
furd:tlon~; J.f}-fi:.f

76H 16 Lil
7711 ![1-lfil
RO\.! l!IOS
en<1hte/dis;1h!t' 25G character
1~T;:q-1hic font J ;-_i -:30
font HAl\1 aad colnr rm;p support
I c)<l t
read charat:.t.(·-r ;:Hui attdbote ::tt

c11rsnc
read curre·n t videq s-r:Dtt~ 1;J·2 'J
rf.ad fHr~cff uqsitJnn LJ~ J. 4RUM BIOS :mnl disk
; f.-lr l
HOfvl BIO~ i:;if51iliza'.vn:
H·

HOJ\l BIOS
02 f·J

1 b~'.L

nsn 15··~
Oki·{ : 2i·t~l
OD.ti: :~.;~
fiBI-i l ;);~)
UCH J:i·''
flEB 15-7

~ 5 . . 76

<_:;('roll act.Iv•_~· pf1_ge d.ovdl 1b- sc.roU ~:tf.tive p~~ge up l 6- .t 7
ser, cnl.or paiPtL(~ l. 6---~_)::
set t~.t_:;_rsor
;..:,t_--d: ·:~:..:rsnr r-,ypc
::__.:E~t

Si.'t

L~~;~ 1 ~;

l_ C~- 16
n1ctde 1G~10

r~T1te i.:hau:H_~~.e,r ;~nd

\\'rite thaL:ic~i:::r
cn1u~nti>'.").!1

utt.dhute at

l(j-£(}

CU!"!--;Of

! ;:j-L'~~

t. ern~i11a.J

vnitc

P"<rended mode 1 f>-77

RtYV! Bl.OS interrupt i1H. l;)-:l8

diskette etT{H'~-i 15-~=·~::i
di~kdti-o firnctionq ! :1. 59
diskette pnrarr1erH 1'1bfe:; H•-59
•;xecute cnntroliBr internal diaµ:nvstlcs 1 ;j<.)H
forn1(1t ~l track 1i)~.J1, l fi~6G

hard disk
errf;rs 1 ri~:tO
h1netions 1 ~-,10

j !)~ r~8

reod one· or ff\(H~e di.sk -se~~t..ors
15--4-~

rend one nr n1ore trQck sectors
J.5~63

P'!(OliiJra.te drlve 1:),-{) C~
iitH.?' St-<JtUS l ;)~68
currt·nt drive paran1ctcr~ i f~-"Ui
drive t,ype 1f1·-t~'i~ 1fi-G7
statu~ cod_f• 0t lust I'/() requ(:st
1:')-.:rJ 1 :·:)~62

set dr:ve Etnd_ ruedi~J ~:.vpe ror
format l ~··HH

1.f,. 'j:)
•wnd break l tH:l 4
St:t. baud rate 1 f>--87

sei mnd1'm eontrni l fH<5
tnin"mit chcirm:ter l [;-7;~

virtual rnode l G~nfl
r·.lost device l f! .. 8 H
dr'vfct: 1:~ husy J. t1-98
~'on1pletion h;:n1dlnr ·t 6~}J8
joystick support l 5-91
nH1\'(! a biock of JTH~rnt)ry J5 .. D3
open df:vice J [1,. 89
retnrn
confl~..n~ation word
lG-qn
n·tun1 me.morv sb:e above one
) ;).:Jf>
requi:st key 1 f.i-91
set a \vait interval ;) .. fJO
b.:~rrnin.atlon 1£)-·90
wait 1mi rntnrn h.i user\ i;"}-~12
R.Ol\1 F\[OS

characr:t:-•r f~onnt l :J.-1l4
t;;xtt·'nded cod~s n.nd function~
1 :-j- l i_)
nut.ificD ti on l.f>· l 1 l
buffer 15-1 J.5
l[i-[l);)

statu<; !5109

.l 3~4 (~
nrv-~ or

retry on timeout error Jfi-86
return
port status

lHJ\'1 BJOS interr:J.pt i.5H .lfi-88

panuner.er tables l f1~4 J
rc·set 1 ~~~<~:3
inibal.izc
diskcttf!

f'f'.F:ld i·iJn~~ 2 6fi byte be<. tor
read
1b-50

initialize il'>ynchrmwus port 1:>-72
receive charar:ter l ~-'i~74

Hlo:.'n:e ~-rack :-:a~ctors

2. ;1--nr~

kevl)oard tubie pr)inters l ft~12(1
neqnes'
ID .li"J.1 !8
send to keyboard Ir,,. J \!cl

HOM B!OS interrupt 17H .lfi-12;}
'/"t'l'ite u11e or n10;:1:: tra.i.~k s.f~ctors

c' fie\

pnrt retry l
prmtet· type l h· l 2!)
red.itr:ct p:Jn1ilt31

'.\ l

; ;<·127

R{)f\II BI{)S int.PtTupt 1 /\TI I L~-J ~~5
::~·\:H1cel 2h1n;.1 1f;-J4!)
re~:1d reaJ-~-irnt! t··l·:)ck l ;J. ·t ~~ 7
r~~sd s_y-sb:rr-, •:lock. t ;~'.- i ~{L

·sin:_:e-re.ad ccdn1'/~:· t ~)-_:; :H)
d~~t~;
s~t a:an11

lfi-_L_,jh

lf1~1_39

ser re<i.!·ti<'nc d1wk i :.· 1 jg

1;,.14\l
ret_.u.rn rt-r (late l G~ l ;-H~
s+::t <tl.a.r1-~1 J 6-13fi
:'~~r rr~ai-t.lrne clock tb-t:·t:~

BOM FHOS ti.rue: tick iLterrup'
~ 6~ 1Jt !
H()t\<1 HJ()S \ri.d.t::.-,,~
r":"1oat-:s ~-ti·~ l 0

HC!!\'l _P;J()S ,:-id.etJ

:inter~

P..ipt j_:-.,~s

1£~ ~i~
rJ1dr;J(.t_-~-~t ".:.:'.(E)l~t

1. ~-)- L 14

f(•r~~ H.i\!\'1
·;_ S-iJ 'J

Jnd color fft~:i_p _{iupp•.:nt

iunr~r1~_1n_:s

1f,;-9

n:~ad (_ ~h_~-:rac:;cr ~u1d

r{'.:id

b1__;_ ~fr:·;'"""'""-'···~" hip~_!t

i ;-:;_ ~ t G

c1_ 1rrc:n:. \;'idfn st.at.(• ·1.c~·Z'?

ref~('.

r~;aid

l(;-JI)~)

nnr:.ific:-_;_~ion

att< ibt~;:~" ..:~-...

JG-1'!

r... irsi:;r

~> ~-] l

state .Lf7 110

read p\

"'"! i f,. :) I

~;;c~-ur ~H'.i:Jyt~. .

p-age d.iJ\·Vn

j G~ J 7

Si.TOH ~-tct.i>v·~ p;Jge up l.fi~I.7

~ct ~:u-,·s:·n·

t,ypc• '· <-;-1 ~

; :_) 1r;

fVJ!\:i B iiJS pt ,ntt~r cut.pu~- ~.ntr.;;:T1~_s•t

t ~-;~:IO e

.l f}-J20

i ~-; -1 ~)

\'vr;.tt c~·!;)J a.ctcr £.~nci dttrihutt' .:~H
v'vTitt; ch~1ract~~r ~!.~.

c(:tun~ prLnt,~r ~~tat~!.:;;
t~';,~n;r,;rr:;_t ::h~!.rr~ctc;·

_,_ 6~ l.2€3

tf>-1 :.?<-i_

C{:~nc~.:~ D~;.-:;- n, 15~'! 40

1:J ; J 7
tr::1a ~rvstf;rr;_ clc(k J.Ci· ;~G

r~~c n_~Ed-t:~rie c~orJ:

1t::.. 20

t.~Jrsor

pr lntf-T t:)ipC t :')~ .1 'lH

red;, e.·t

v,:ritJ: t:hJrt!1_:~tc·r
e:.nuk1rl«"H1 1fi<::!t~
\-Vt_iT:~·; pj~"t:•j

j ;)<~;3

DM!\ nmtrolier 4-5

break signal for LAT l 8-7:L
br(l11dr·ast for sessi.on 18- U G
data frH' L.'\'f l 8-fif1
for session .18-114
double for session l.8-l IO
fur session J.8-10;)

HTC alar.m intnrrupt \~,-l 48

s
Scrn1 (Ode~ 15~102
LK250
8 Hi. 8 I 7
t.rctn~iated 'but not us~tl 8·,2'1

Send b re:i k fo nction l ~1-t\4

Scan eqna~ co.tnn1Hnd

SendLritBre£Jk l 7-70

function l ~'~ l 1 ~~

Send to

Sen-,.(;

diskette <ld\-'t: controller
register sct:.'1 1.1·24

Scan

nr equal r)rJmmand
dishd.tc d1.frc omtruller

Serial

sds I l-2b

data !l-l

prmtcr port

Scan J.ow or equal l'rnnrnand
disk\'t.b> drive nrntrnller

hlt stn-~;u11, conve·rled b~r LA.NC:E
l :).;j

StrIJil Bt:":tive page do·wu tunetion 1 f>l7

int.erfoc(~

S+"rver nlessage block

g, l27

Sc:rv \.(t'18,-fl(J

t:Jb1u reset for l..-lYr 18· 71.
S)·Stt:tn n:nnest l·;.e:y function 1 f>~H J

Sector
l ~~"--;

COUJ1-t

i ntedea;:E: 12- '! 8
nurnher
t :2--,;
Set~!-~

st<•rt for U\T .,fH,7
status word 11'.. ()'.-l
fo1 LAT Ui ;)7

con-1rn::1nd -1_'.!*t~:1

rrotifict1tir)r'< routin{~.

diskette drive controller
Seti'i

1 J ·27
J.svnchrqnuu.:; requ+,sts J S~f;f~

Seek to

fl.11:.ctlons 1.8-91
,Kld a nod(.': J .s:-.-120
,,c]d n:rnie 1.8·!01
•.:oi' i 8-l 0!)

•.··ompusc
niJnr1nc.k

7-G

('£-lticel 1.8-97
1 ~on.trolfr:r

b-12

Se1f-t.est fa~.htr0

Ll\200
Sett~test sur;ct-:ss

Ll\:'.fiO kevb•Jard re•;fHlnSes s-:rn

Send

cht~ck for pre.senee J 8-HH
delete uH node entries 18~ 12t¥
(k•k'.t,B cnt.ry
node n.arne
i8 l. 2:~

dtlete t.:·ntr_v .~dvPn node ntunber.
HH2i
....
dtdetr-: nan1f) 1H~lt)'.C

lude'.'I.

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h~::n~::;up
listc~--1

J-8-Ju.g
iH-J07

n-iod.f~

runT\ 0 s t.n ~,,;) ~ _;,_ .'j ~ .'. _ ;J ~i
rt~Hci ::1odt~ '~nu:y

index

l8··]2b
fL~Eli.C· ~ 8~ J 2 --1
:-ead node cntrv g:n. f::.11 node
nu::YiLie~-- .! 8- t 23
l t~~.>:~'rVC : -\;< l )-_
1

•,:oiurf;J; f~-~~4
fun:·;:.ion tG~ 1U

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page fuu~:ti.nn l r~ . ! n
p;1nn~1eh-..~rs c:-r-Htirn;·Htd J :;~~£:2
re.'.d-lirnc clock fuaction i ~)--J :~ B

frrc t:k1t;t:i funLth,;n l ;), l ~)9

sy~>tPtn I_'lock functJuu

1 G~ l 8U

\··ide(; tnr.ld\~- h.ul;;·t.Ion J :~~~ .tU

·:.:end lE~J 05}
scn\t l1t1_~i±dt.:'.;_ist ~- B-11 G

S!A - :+::to. Smia!. !nterfoce .'Vfaptc1
: :,~ 2
cccrun1n~icatl.r;ris <{)nJh:ctor 9~1 !J
r~1()dr:rn

18-f52

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o\·e~:vic .,~,

j. ::-:t- S~J

rnt:J:":1 ~-~nd«":::B .ts-n:~

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field~

bk:{:k. t.SC~HJ l H-8f~

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LfiH1SfC>r l1'Uf)(t0

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get '.,~t_;rn::irc c-L~itc r~nd tirut: 13· -~ 2~~
ov•:~r·.'it:·~v
8- .1. 27

·::::.t~~_nr:.l'}'

code fut~cti;."?P l G H
('Ur~.:-Jr~ ;xnit.io:~ h.~nrt·lon J 5~ 1~:;
c:~r.r-<ur type- fu~1_c~. io(:
V~iilH?-~1 l ~J- >~

t")oft- 1-":.Tr(· in:(~rrupts
asy~';t'-J 1rnnou'.S i.''.O~l-, in nJ1;c.t;J·~on:t:•

I ~J-70
bas.le '1 :~}.

a::

k€.vbo;n~d l1reak i h· :1 41
ke_v~".!'CK1:r-ti input l~i~LOl

ret.i_~_rn

;1113111.ur:.: size· 1s~:j7
i:1te_rrupt 13h .L-:~-1.4[)

Hc:.\·'tJ:t.fir of

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t.l1 r et"·~r :-~(:.t ~-~1~f:':'i. ro:.zn.t-1.::c ~.'lti.i:l

1rrc; nI(l'_~n1 Jc~~t4~
;~~1.;~fi

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v~deo

s pe;,:i.f..::e~·

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1f~-14 1

J.;:}-B

S0Jt¥var0
thr(;~::-<-~1DnJ:1~l (Od.;·)ti:-;_1·

and
SYSH.E~-~

SOHT.CXF.

o·:nvci dp A--4
H :\ fv1 pt."?\'-i{~rur; t~·'.;d ~·,¥»eek~~- l 4-8

~re~,t~i.~.r~11 f;:r;ni;-~titY1
.'.~UJ~t

Sou:1fe './i.t>t·vt;:! ntudf~l
~1.~n-;t_;vch.annci t..'.f:-urj_t,(:r :;:Jnd

size ~ !~?,-)

St.~tndard r.on1tcu.ni,_'?1ti1:-1\ of ~_.h('

\-':11J(rn~·1te v/o-rl.-~sttttinn

; ~~.~~'
·-t~r_sc;r ;~:··~-f:

~~UL";(¥f :~:L?.:.t.;

~~;ta tu~

bufh~.r f'ni- se'.~s~on 18~ 1.00

"4. .g
/-f)

<'._'.0!_:1nr~-:'t and

H~20

-speak.er

-::0unter~lntrh (e>n:1r:.:Li.nd
rr1cdf.~

G- i i )

User crdl,b.;1c,~: t\.P.J..dnc;; f(Jf d~n.a.!.l.n.k
i8~8

G-4

·.. ~ode 2 ~3--S

.'..iddr>~SS d•)f"f_::th~
rn.od~; d"'__!fi1d-.:,inn~-;

f;, ;~;

n1c1 d;:~~ n:· GP\~:~~tcinn

"L:i~4

f:.-'li

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f';'.:~~T1Dle G~ ~ G
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LU buard LH
l/(l hu.~ L"l·Cr

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! ;J--40

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th· 46

J 5-k, I;>.<;
:no(fr:~~
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f: _ ::cz::~,;1_i(":

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f:_:n· dn~,.~~Lint.. l.S-l ~L l B<':~

i_!;- j '.': 1 4

foi: the Hf.JfvI l_Hf)~,. _;_~) l(-5

1i_irh:(• ~_:q•1teA~ct

cokn: ."-,·~·Ice!:

{'.ocL-o] rei~i~te~- :\
f_,,t,v~1clard

di ffoncnccs f'. i. 2
PrintPr to Hl.lst mode Cl '1
SC'S C-14. C I fl
video <liffercnce~ (:.J.O

tllrt~S 'J'·2
video tnndes ''.,;~}
•vdte datn reidstr:r 7 :1H

Virle1) rnernot·y 7 <-~
Viden ffiodc'.', 7-r;
insicte ;i window 17-'i!J
no .ROl\l BIOS
lJlUlTAI <f:'XtnidPd 7 l :L 7 J ·+
HOM BIOS

\\'indows

711.7-l~~

HOTvl B!OS

UIGIT!\J. extended 7·F:. 7-Ili,

:-.'

i) ' ~

§".:,,;'...

Vittua1

HHHJe

14-8

'./T'220
add~tion~d

ernulntoc (~~c.;;1pe s~~,

\Vrlte
nil .nia.i..:_k .bit:S 4~J
charLwt.er ,_-n1d ;:{ttribut•! at cur~o~·
position 1 f1~20
ch~.1ru.<:t-f:r .:n. cursor

chn rarter

1 f-·<~ J
:.crrninol t;1111 da tinn

l :~l~ 2 :')
t6r•fd

quences C:'~fi

one nr rnon~~ track ser_·.t-<:n-.~ l fi.-{}4

C·8

on!' ur rnore disk sPttor'> ! fi·4Zi

chart.lrter set differenrf~s t·:.:)
COll1\W,ltlicntions rJiffPlTOCt:S (;.:{
D.\ ()·8

vVrite command
eont:ruli.er 8-.l 0

DECAUPSS C (;
\V:··it-e d.:1ta cnrnrnand

DLCH\]UPSS C il
difft0·-rcnr:e~s betv,,11:~f:n r!rnu\Rtor c:1nd

terminal C.Z
diffon.·nce'., (' .. \
prindng (\-~)
SCS CG C·i
-,,--ideo dlff~~n_:nces C -'2

VT2 /~t)

i:.tddit;_cnal en:nd8.tor- <~S(Hpt~ se~
QlHffi\.'.SS ( - ] ;]

C. G
cb.:J.ractcr set differr:nces (> l J
1:0!lTfHUflici1tk.l!lS diflcrenc.r::S (• 1~--~
DA C-1. fi. C 1i.i
DF:CAUPSS C-13

C-1.·l

differcni::c bct.1,vePrt ( rn.u)ator at1d
t('n11in<tl C- l 0
1

t1i . J:('.ttt:;. dr.i-ve controller

\V r.\.tf~ ch-;;letc·d ch1ta cornrnand
c!iskeL::e drive controller
sets l l<.'.2

\\!rite port 2 command
cnnt.roller 8-13
\Vrit?:' pre{~on1pensatinn rc.giste:r

l.2~4:

sec:. or ci;,.a1nna.nd l~>tb
mA<:k bir 4·11
stilt.us
•·ommanrl keyboind ..
interf~K',::. cunrxoih.-~r 8·· l :·~

Technical Reference hllanuai

Volume i
AA-JP76A-TH

Reader's Cornmeots

f'..X<~t:!i.•;n1
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- ;:1:__~1~; c~-- (:~)nt<·.1~r:·;

.J
>~ry:~

i_J

~:;~·in~. (~~u;1L~v

Dept.
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Poor

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Technical Reference !v!anua!
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\\/nae '-'i~ggc,..;n,_n:.s d '.• \:ot·i h~l-"'\';:'· t~.)J
nct.~,-:."~;.:r\.

~rnp1Tf·1·in~.; thj~- rn:11H:a!'i'

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