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EK-VT100-UG-002

January 1979

82 pages

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3.9MB

Document:	VT100 User Guide
Order Number:	EK-VT100-UG
Revision:	002
Pages:	82
Original Filename:	http://bitsavers.org/pdf/dec/terminal/vt100/EK-VT100-UG-002_VT100_User_Guide_Jan79.pdf

OCR Text

E K-VT1 OO-U G-002

1st Edition, August 1978
2nd Edition, January 1979

Copyright © 1978, 1979 by
Digital Equipment Corporation
The material in this manual is for informational
purposes and is subject to change without notice.
Digital Equipment Corporation assumes no responsibility for any errors which may appear in
this manual.
Printed in U.S.A.
This document was set on DIGITAL's DECset8000 computerized typesetting system.
The following are trademarks of Digital Equipment Corporation, Maynard, Massachusetts:
DIGITAL
DEC
PDP
DECUS
UNIBUS

D ECsystem-1 a
DECSYSTEM-20
DIBOL
EDUSYSTEM
VAX
VMS

MASSBUS
OMNIBUS
OS/8
RSTS
RSX
lAS

CONTENTS
INTRODUCTION
CHAPTER 1

OPERATOR INFORMATION

PART 1 - KEYBOARD CONTROLS AND INDiCATORS ..............................................................................................4
Monitor Controls .........................................................................................................................................................7
Audible Indicators (Tones) ...............................................................................................................................7
PART 2 - SET-UP MODE ....................................................................................................................................................8
SET -U P Features at a Glance ..........................................................................................................................8
Determining What a SET-UP Feature Does ............................................................................................... 10
How To Change a SET-UP Feature .............................................................................................................. 11
Setting the Answerback Message ............................................................................................................... 12
Saving the SET-UP Features ......................................................................................................................... 12
Recalling SET -U P Features ..........................................................................................................................,12
Resetting the Terminal .............................................................................................................................",,,.13
PART 3 - DEFINITION OF EACH SET-UP FEATURE .................................................................................................. 13
PART 4 - SELF-TESTING THE VT1 00 ........................................................................................................................... 16
Self-Test Error Codes .....................................................................................................................................17
PART 5 - WHAT TO DO IN THE EVENT OF A PROBLEM ......................................................................................... 18
CHAPTER 2

INSTALLATION, INTERFACE INFORMATION AND SPECIFICATIONS

i nsta liation ... ,.......................................................................................................................................................................21
Site Considerations ..................................................................................................................................................21
Unpacking and Installation .....................................................................................................................................21
User Maintenance ....................................................................................................................................................24
Interface Information .........................................................................................................................................................24
EIA Interface ..............................................................................................................................................................24
Optional 20 mA Current Loop Interface ...............................................................................................................26
External Video Connections ....................................................................................................................................27
VT100 Specifications ........................................................................................................................................................28
How to Order Hardware Documentation .......................................................................................................................30
CHAPTER 3

PROGRAMMER SECTION

The Keyboard ......................................................................................................................................................................34
Communications Protocols ...............................................................................................................................................40
Terminal Control Commands ........................................................................................................................~ ...................42
Control Characters ....................................................................................................................................................42
Control Sequences ...................................................................................................................................................43
Valid ANSI Mode Control Sequences ...................................................................................................................43
CPR Cursor Position Report - VT100 to Host ...........................................................................................45
CUB Cursor Backward - Host to VT100 and VT100 to Host .................................................................45
CUD Cursor Down - Host to VT100 and VT100 to Host ............................................... ,..... "",,.
. "A5
CUF Cursor Forward - Host to VT100 and VT100 to Host.. ...................................................................45
CU P Cursor Position .......................................................................................................................................45
CUU Cursor Up - Host to VT100 and VT100 to Host.. ............................................................................46
DA Device Attributes .....................................................................................................................................46
DECALN Screen Alignment Display (DEC Private) ...................................................................................46
DECANM ANSIIVT52 Mode (DEC Private) ...............................................................................................46
DECARM Auto Repeat Mode (DEC Private) ..............................................................................................47
DECAWM Autowrap Mode (DEC Private) ..................................................................................................47
DECCKM Cursor Keys Mode (DEC Private) ...............................................................................................47

DECCOLM Column Mode (DEC Private) ................................................................................................... .47
DECDHL Double-Height Line (DEC Private) ..............................................................................................47
DECDWL Double-Width Line (DEC Private) ..............................................................................................47
DEClO Identify Terminal (DEC Private) .......................................................................................................48
DECINLM Interlace Mode (DEC Private) ....................................................................................................48
DECKPAM Keypad Application Mode (DEC Private) .............................................................................. .48
DECKPNM Keypad Numeric Mode (DEC Private) ....................................................................................48
DECLL Load LEOS (DEC Private) .................................................................................................................48
DECOM Origin Mode (DEC Private) ............................................................................................................48
DECRC Restore Cursor (DEC Private) .........................................................................................................49
DECREPTPARM Report Terminal Parameters ......................................................................................... .49
DECREQTPARM Request Terminal Parameters .......................................................................................49
DECSC Save Cursor (DEC Private) .............................................................................................................. 50
DECSCLM Scrolling Mode (DEC Private) ................................................................................................... 50
DECSCNM Screen Mode (DEC Private) .....................................................................................................50
DECSTBM Set Top and Bottom Margins (DEC Private) .......................................................................... 50
DECSWL Single-Width Line (DEC Private) ................................................................................................ 51
DECTST Invoke Confidence Test. .................................................................................................................51
DSR Device Status Report ............................................................................................................................51
ED Erase In Display ........................................................................................................................................52
EL Erase In Line ...............................................................................................................................................52
HTS Horizontal Tabulation Set ..................................................................................................................... 52
HVP Horizontal and Vertical Position .......................................................................................................... 52
IND Index .........................................................................................................................................................53
LNM Line Feed/New Line Mode ..................................................................................................................53
NEL Next Line ..................................................................................................................................................53
RI Reverse Index ............................................................................................................................................. 53
RIS Reset To Initial State ..............................................................................................................................53
RM Reset Mode ..............................................................................................................................................53
SCS Select Character Set ..............................................................................................................................54
SGR Select Graphic Rendition ..................................................................................................................... 54
SM Set Mode ..................................................................................................................................................54
TBC Tabulation Clear ......................................................................................................................................55

Modes .........................................................................................................................................................................55
ANSI Specified Modes ...................................................................................................................................55
DEC Private Modes .........................................................................................................................................55
Valid VT52 Mode Control Sequences ...................................................................................................................56
Cursor Up .........................................................................................................................................................56
Cursor Down ....................................................................................................................................................56
Cursor Right .....................................................................................................................................................56
Cursor Left. .......................................................................................................................................................56
Enter Graphics Mode ......................................................................................................................................56
Exit Graphics Mode ........................................................................................................................................57
Cursor to Home ...............................................................................................................................................57
Reverse Line Feed ...........................................................................................................................................57
Erase to End of Screen ...................................................................................................................................57
Erase to End of Line ........................................................................................................................................57
Direct Cursor Address ....................................................................................................................................57
Identify ..............................................................................................................................................................57
Enter Alternate Keypad Mode ...................................................................................................................... 57
Exit Alternate Keypad Mode ......................................................................................................................... 58
Enter ANSI Mode ............................................................................................................................................58
Control Sequence Summary ...................................................................................................................................58

ANSi Compatibie Mode ........................................................................................ ,.,"", ..... ,.................................... 58
VT52 Compatible Mode ..........................................................................................................................................61

CHAPTER 4

VT100 OPTIONS

Advanced Video Option - VT1 XX-AB ................... ,......................................................................................................... 65
Advanced Video Option Installation ......................................................................................................................66
Advanced Video Option Checkout .........................................................................................................................66
20 mA Current Loop Option - VT1 XX-AA .....................................................................................................................68
20 mA Current Loop Option Installation ............................................ " .......... " .................................................... 68
20 mA Current Loop Option Checkout .................................................................................................................69
Communications Cables ....................................................................................................................................................70

APPENDIXA

ANSI DEFINITIONS AND NOTATION ................................................................................... 73

APPENDIX B

7-BIT ASCII CODE ........................................................................................................................77

APPENDIX C

FILL CHARACTER REQUiREMENTS ..................................................................................... 79

OTHER TERMINAlS ......................................................................................................................................................80
FIGURES
1-1
1-2
1-3
1-4
1-5
1-6
2-1
2-2
2-3
2-4
3-1
3-2
4-1
4-2
4-3
4-4

VT1 00 Terminal ............................................................................................. ,,'
",." ........................................ 2
VT100 Keyboard ..................................................... ,.............. " ............. " .. ,... ,.. ,' .. ,... ,.. " .. ,."., ........ " ... ,."., ........... ,.... 4
VT100 Terminal (Rear View) ...........................................................................................................,...................... 7
SET-UP A Mode Presentation ....................... " .......................................................................................................8
SET-U P B Mode Presentation .................................................................................................................................9
SET-UP B Mode Summary ......................................................................................................................................9
VT100 Terminal Dimensions ................................................................................................................................22
VT100 Rear View ...................................................................................................................................................23
20 mA Current Loop Interface .............................................................................................................................26
Composite Video Output .......................................................................................................................................28
Terminal Data Flow ...................................................................... ,.........................................................................33
VT1 00 Keyboard .....................................................................................................................................................34
VT100 Rear View ...................................................................................................................................................67
Advanced Video Option Installation ....................................................................................................................67
20 mA Current Loop Option .................................................................................................................................68
Terminal Controller Board .....................................................................................................................................69

TABLES
1-1
1-2
1-3
1-4
2-1
3-1
3-2
3-3
3-4
3-5
3-6

Categories of SET-UP Features ............................................................................................................................ 10
SET-UP Feature Change Summary ........................................ ,.... ' ....................................................................... 11
Nonfatal Displayed Error Codes ........................................................................................................................... 17
Problem Checklist ................................................................................................................................................... 18
EIA RS-232-C Connector Signals .......................................................................................................................24
Machine States ..................................................................................................................................,', .. ,.. ' .. ,., ....... 35
Alphabetic Key Codes .......................................................................................... ,... ".' ................. ,....... ,.... ,", .. ,.. ,.. 35
Nonalphabetic Key Codes .. ,.. ,........ ,......................................................................................................................36
Function Key Codes ...............................................................................................................................................36
Control Codes Generated ......................................................................................................................................37
Cursor Control Key Codes .....................................................................................................................................38

3-7
3-8
3-9
3-10
4-1
C-1

VT52 Mode Auxiliary Keypad Codes ...................................................................................................................38
ANSI Mode Auxiliary Keypad Codes ...................................................................................................................39
Special Graphics Characters .................................................................................................................................39
Control Characters ..................................................................................................................................................42
Available Communications Cables ......................................................................................................................70
Fill Character Requirements ..................................................................................................................................79
Installation, Warranty and Service Information on Inside Back Cover

INTRODUCTION
The VT100 terminal is designed to work very much like a typewriter. This guide
will tell you everything you need to know to use your terminal.
A checklist label is provided for making a semi-permanent record of the features.
unique functions. and mode of operation of your terminal. Place this label under
the keyboard and keep it up-to-date so that you will have a quick reference to the
basic status of your machine.

CHAPTER 1
OPERATOR INFORMATION
The VT100 is a simple device to operate. The terminal (Figure 1-1) is basically a
typewriter that uses a video screen instead of paper and communicates with a
computer. If you can operate a typewriter, you can operate a VT100.
Chapter 1 is divided into five parts:
1.
2.
3.
4.
5.

Controls and Indicators
Setup Mode
Definition of Each Setup Feature
Self-Testing the VT 100
What to do in the Event of a Problem

Part 1 shows all the controls and indicators on the terminal and summarizes
the function of each, thus providing a quick reference for these functions.
Part 2 defines the SET-UP mode and briefly summarizes its features.
Part 3 describes each feature in detail. Refer to this section if you need
further information on a feature mentioned in the SET-UP Summary provided
in Part 2.
Part 4 provides information on self-testing the VT100. It outlines the steps
required to start the built-in self-tests and how to interpret the results once
the tests have been run.
Part 5 provides a procedure to follow in case you encounter any problem
with the VT100. Easily recognized failures with simple corrective actions are
provided for each symptom. Check the list on page 18 before calling for
service.

Figure 1-1
VT100 Terminal

OPERATOR INFORMATION

PART 1
KEYBOAR D CONTROLS
AND INDICATORS

The VT100 terminal normally performs a two-part function. It is an input device to
a computer - information entered through the keyboard is sent to the computer. It
is simultaneously an output device for the computer - that is. data coming in from
the computer is displayed on the video screen. The following controls and indicators on the VT100 keyboard are illustrated in Figure 1-2 .

••••
••••
••••
···1
...
Figure 1-2

VT100 Keyboard

•

SETUP

This key is used in conjunction with other keys to perform specific functions such
as setting tabs. scrolling. and altering terminal characteristics.

ON LINE
This indicator lights to show that the VT100 is on-line and ready to transmit or
receive messages.

LOCAL
This indicator lights to show that the terminal is off-line and cannot communicate
with the host device. In local mode the keyboard remains active and all characters
typed are placed on the screen.

KEYBOARD LOCKED
This indicator lights to show that the keyboard has been turned off. The VT100 is
still able to receive data from the host. This condition can be cleared by entering
and exiting SET-UP mode.

L1-L4
These indicators are turned on and off by the host. Consult your local operating
procedures for the meaning of each indicator. L 1-L4 are also used to show selftest errors .

••••

Each of these keys causes the VT100 to transmit a code which has a special
meaning to your system. Consult your local operating procedures for the meaning
of these keys. In SET-UP mode the
and
keys increase or decrease the
brightness of the display. The
and
keys move the cursor left and right.

•

a aa a

BACKSPACE

This key transmits a backspace code.

OPERATOR INFORMATION

•
BREAK
This key transmits a break signal.

• • • • PF1-PF4
Each of these keys causes the VT100 to transmit a code which has a special
meaning to your system. Consult your local operating procedures for the meanings
of these keys.
Numeric Keypad

The numeric keypad enables numbers to be entered in calculator fashion. Each key
in the numeric keypad generates the same character as the corresponding numeric
key on the main keyboard. The ENTER key corresponds to the RETURN key.
These keys may also be interpreted by the host computer as special function keys.
Consult your local operating procedures for the meanings of these keys.

•

DELETE

This key causes the VT100 to transmit a delete character code to the host system.
The deleted character mayor may not be erased from the screen.

•

RETURN

This key transmits either a carriage return (CR) code or a carriage return (CR) and
linefeed (LF) code. This is a SET-UP selectable feature.

•

LlNEFEED

This key transmits a linefeed code.

SHIFT

When pressed, this key enables the uppercase function of all keys. If a key does
not have an uppercase function the SH I FT key will be disregarded.

RESET

When the terminal is in SET-UP mode, this key starts the reset sequence. This has
the same result as turning the terminal power off and then on.

80/132 COLUMNS

When the terminal is in SET-UP A mode. this key switches the display line size
from 80 to 132 characters per line or from 132 to 80 characters per line.

RECEIVE SPEED

When the terminal is in SET-UP B mode, this key steps the terminal through the
receive baud rate settings in ascending order.

•

TRANSMIT SPEED

When the terminal is in SET-UP B mode, this key steps the terminal through the
transmit baud rate settings in ascending order.

•

TOGGLE 1/0

When the terminal is in SET-UP B mode. this key turns the selected operational
feature on or off.

OPERATOR INFORMATION

••••
••••
••••
···1
...
Figure 1-2

VT100 Keyboard
(cant)

BELL G

When pressed in combination with the CTRL key. this key causes a bell code to be
sent to the host.

SET-UP A/B

When the terminal is in SET-UP mode. this key switches the terminal from SET-UP
A to SET-UP 8 or from SET-UP 8 to SET-UP A.

•

LINE/LOCAL

In SET-UP mode. this key alternately places the VT100 ON LINE or LOCAL to your
system. When it is ON LINE. the VT100 communicates with your system. When it
is in LOCAL the VT100 is electrically disconnected from your system.

CLEAR ALL TABS

In SET-UP A. this key clears all horizontal tabs set in the VT100.

•

SET/CLEAR TAB

In SET-UP A. this key sets or clears individual horizontal tabs.

CAPS LOCK

This key enables the transmission of uppercase alphabetic characters only. All
numeric and special symbol keys remain in lowercase.

•

NO SCROLL

When first pressed. this key stops the transmission of data from the computer to
the VT100. When pressed a second time. transmission resumes from where it was
stopped. Check your local operating procedures to ensure that your system recognizes this key.

•
CTRL
When pressed in combination with another key. the CTRL key causes the VT100
to transmit a code which has a special meaning to your system.
•
TAB
This key transmits a tab code.
•
ESC
This key transmits a code which normally has a special meaning to your system. In
many applications. it tells your system to treat the next keys pressed as a command.

OPERATOR INFORMATION

MONITOR CONTROLS
The VT100 monitor contains only two controls: the power switch and the power
selector switch. which is used to adapt the terminal to the available ac input
voltage range (see specifications).
Audible Indicators (Tones)
There are three audible alarms associated with the VT100: a short tone (click), a
long tone (bell). and a series of long tones.
Short Tone (Click) - The short tone is sounded by the terminal whenever a key is
pressed. with the following exceptions:
• SHIFT or CTRL keys do not generate any keyclick because these keys do
not transmit any codes but only modify the codes transmitted by other
keys.
• KBD LOCKED indicator is turned on; in which case. the characters typed
are lost.
• The keyclick feature has been turned off in SET-U P mode.
Long Tone (Bell) - The long tone is sounded by the terminal to indicate one of the
following conditions:
• A bell code was received from the computer.
• The cursor is eight characters away from the right margin and the margin
bell feature is enabled.
Series of Long Tones - The terminal will sound the long tone several times in
rapid succession to indicate that the nonvolatile memory (NVR) had difficulty in
reading or writing the SET-UP features. (When this occurs. check the SET-UP
features and then perform the Recall or Save operation again.)

ACCESS

EIA
COMMUNICATIONS

.w ••• w··~CONNECTOR

I EXTERNAL VIDEO
INPUT CONNECTOR
EXTERNAL VIDEO
OUTPUT CONNECTOR
MAIN FUSE

POWER SWITCH

MODEL
SERIAL
NUMBER LABEL

KEYBOARD
CONNECTOR

~ OPTIONAL 20mA
COMMUNiCATiON
CONNECTOR

POWER
SELECTOR
SWITCH

CONNECTOR
MA-1987

Figure 1-3
VT1 00 Terminal
(Rear Viewi

OPERATOR INFORMATION

PART 2
SET-UP MODE
Unlike most terminals, the VT100 does not use switches or jumpers to individually
turn the built-in terminal features on or off. Instead, the VT100 uses a nonvolatile
memory (NVR) which always remembers what features have been selected, as if a
switch had been set.
The selection and storage of built-in terminal features is performed in a special
mode of operation called SET-UP mode. When you enter SET-UP mode, the status
of the features stored in the temporary memory is shown on the screen. You can
then change the features and store any new feature selections either temporarily,
by leaving SET-UP mode; or on a fixed basis, by performing a Save operation. In
either case, the terminal operation will reflect the new feature selection. If a recall
operation is performed, or the terminal is reset. or the terminal power is turned
OFF, all temporary feature settings are replaced by the features that have been
stored on a fixed basis.
SET-UP Features at a Glance
When entered, SET-UP mode provides two brief summaries of the current feature
status. The first presentation - SET-UP A - displays the location of the tab stops
set in the terminal and a visual ruler which numbers each character position on the
line. The second presentation - SET-UP B - summarizes the status of the other
terminal features.
SET-UP A - To enter SET-UP A, press the SET- UP key. The display wi" now have
a presentation similar to Figure 1-4. The bottom line of the display consists of a
"ruler" which numbers each character position available on a line. The location of
each tab stop is shown by a "I" placed above the ruler. If the tab stop{s) set are
those desired, you may exit SET-UP mode by pressing the SET-UP key again or
you may now change the tabs to meet your requirements.

SET-UP
A
TO EXIT PRESS ·SET-UpH

Figure 1-4
SET -UP A Mode Presentation

OPERATOR INFORMATION

SET-UP B - SET-UP B mode may only be entered from SET-UP A mode. To enter
SET-UP B from SET-UP A, press the 5 key on the main keyboard. The display will
then look like Figure 1-5.
Figure 1-6 summarizes the SET-UP B presentation. This summary allows you to
quickly determine what features are enabled. For additional information on a feature refer to the Definition of Each Feature section.
To exit SET-UP B press the SET-UP key.

SET-UP B

~,J

- -- -

Figure 1-5
SET-UP B Mode Presentation

MA2733

SCROLL [0 = JUMP
= SMOOTH

AuTOREPEAT

I
I

SCREEN {a = DARK BACKGROUND
~ = LIGHT BACKGROUND

CURSOR

ilr -

·
llir
I

r--r:II(SHIFTED)

(0 = OFF
tl

I
i
II

= ON._

II I

llirl.
I

JO = UNDERLINE
l1

= BLOCK

III

I II
I

I I

Ll = ON
{a = OFF
\..1 = ON
INTERLACE
= OFF
1 = ON

L·

AUTO XON XOFF (0 :
\..1

· L ANSIIVT52 {a, == VT52
ANSI
I
L KEYCLICK [0 = OFF
BELL

= OFI=

NEW LINE

L - - MARGIN

VvRAP AROUND [0

OFF
ON

L' = ON

{a, =_ :

{a = OFF
1 = ON

(OPTIONAL
DISPLAY
FOR CUSTOM
FUNCTIONS)

~~ :::::::::

T SPEED c:::=J

R SPEEDc:::=J

{a =:

1111-

I I I L POWER
I I I

60 Hz
1 - 50 Hz

I. L BITS PER CHAR . {a1 == 78 BITS
BITS

PARITY

{a = OFF
= ON
{a = ODD

t...1

PARITY SENSE

t...'

= EVEN
MA-1988

Figure 1-6
SET-UP B Mode Summary

OPERATOR INFORMATION

Determining What a SET-UP Feature Does
The SET-UP features are basically a series of options in the VT100 that allow the
terminal to be tailored to its operating environment. Table 1-1 lists each feature
and places it in one or more of the following general categories:
I nsta Ilation
Computer compatibility
Operator comfort
The installation category concerns itself with the initial installation of the terminal
and any special options that may be attached to the terminal. If any terminal
options are added or removed. or the physical location of the installation is
changed. verify the settings of these SET -U P features.
Computer compatibility contains the features which must be set correctly so that
the VT100 can communicate with the host computer. An error in these settings
may cause incorrect data to be sent to or received from the computer; or an error
may prevent the VT100 from communicating with the computer. The settings for
these features must be obtained from the host computer programmer. operator. or
system manager since there are many combinations of settings designed to work
with particular computers and special software. These feature settings would normally change only when you need to communicate with a different computer or a
unique software package.
The operator comfort category contains the SET-UP features designed exclusively
for the operator. These features allow the operator to tailor the VT100 to fit individual preference. These features do not affect any operations that occur between
the terminal and the computer.
The next section. Definition of Each SET-UP Feature. describes the specific function of each feature.
Table 1-1
Categories of SET-UP
Features

SET - UP Feature

Installation

Computer
Compatibility

ANSI/VT52 Mode
ANSWERBACK Message
AUTO REPEAT
AUTO XON XOFF
BITS PER CHARACTER

X
X

CHARACTERS PER LINE
CURSOR
INTERLACE
KEYCLICK
LINE/LOCAL

MARGIN BELL
NEW LINE
PARITY
PARITY SENSE
POWER

X
X

X
X
X
X
X

RECEIVE SPEED
SCREEN BACKGROUND
SCREEN BRIGHTNESS
SCROLL
TABS

TRANSMIT SPEED
WRAPAROUND

X
X

(shifted)

Operator
Comfort

X
X
X

OPERATOR INFORMATION

How to Change a SET-UP Feature
Changing any or all of the SET-UP features is a simple operation and is generally
performed by following the same basic steps.
1.

Enter SET-UP mode by pressing the SET-UP key

Select the appropriate SET-UP mode by pressing the 5 key on the main
keyboard each time you want to switch from SET-UP A to SET-UP B or
from SET-UP B to SET-UP A.

Position the cursor above the feature switch or tab stop to be changed.
Topositionthecursor,theSPACEBAR,
TAB and RETURN
keys may be used. Some features do not use this step since a specific
key is dedicated to changing the feature.

Change the feature setting by pressing either the 6 key on the main
keyboard or the appropriate dedicated key. Each time the key is pressed
the feature will change, generally to the opposite state.

a, a,

Table 1-2 briefly summarizes the SET-UP features, the SET-UP mode you must be
in to change a given feature, and the key used to change the feature setting.

Table 1-2
SET-UP Feature
Change Summary

SET-UP Feature

Changed In
SET-UP SET-UP
A Mode
BMode

ANSIIVT52 mode

ANSWERBACK message

AUTO REPEAT

AUTO XON/XOFF

BITS PER CHARACTER

CHARACTERS PER LINE

CURSOR

INTERLACE

KEYCLICK

LINE/LOCAL

MARGIN BELL

NEW LINE

tA special sequence is required for this feature.

Key Used to
Change Feature

•
••
••
••
••
••
t

SET-UP Feature

Changed In
SET-UP SET-UP
B Mode
A Mode

PARITY

PARITY SENSE

POWER

RECEIVE SPEED

SCREEN BACKGROUND

SCREEN BRIGHTNESS

SCROLL
TABS

X
X

WRAPAROUND

(shifted)

••
••
•
•
••

BorB
Band

TRANSMIT SPEED

Key Used to
Change Feature

12 OPERATOR INFORMATION

Setting the Answerback Message
Setting the answerback message is different from setting any of the other terminal
features. An answerback message can be typed into the VT100. using the following steps:
1.

Place the terminal in SET-UP B mode.

Press the SH I FT and A key simultaneously. The terminal will respond
by placing A = on the screen. (The SH I FT key is required. The
CAPS LOCK key will not work here.)

Type the message delimiter character which may be any character not
used in the actual answerback message. The message delimiter character is not a part of the answerback message. If a mistake is made when
typing the answerback message. type the message delimiter character
again and go back to step 2. This is the only way to correct errors in the
answerback message.

Type the answerback message. The message may be up to 20 characters. including space and control characters. Control characters will be
displayed as a • character to indicate their presence in the message.

Type the message delimiter character. Once the message delimiter
character is typed the answerback message will disappear from the
screen.

Once the above steps have been completed the answerback message will be temporarily stored in the VT100 and can be saved with the Save operation.

Saving the SET -UP Features
SET-UP features may be changed and stored on either a temporary or a fixed
basis. To temporarily store a feature. exit SET-UP mode after changing the feature;
the terminal now reacts according to the new setting. If a recall operation is performed. or the terminal is reset. or the terminal power is turned off. all temporary
feature settings are replaced by the features that have been stored on a fixed basis.
To store SET-UP feature settings on a fixed basis. perform a save operation. This is
a simple operation that is accomplished by performing the following steps:

NOTE
The save operation must be
performed at the terminal
keyboard. The computer cannot perform this operation, although it can temporarily
modify the settings of some
VT100 features.

Place the terminal in SET-UP mode.

Press the SH I FT and S keys simultaneously. The screen will clear and
the message "wait" will be displayed in the upper-left corner. After a
brief wait. the terminal will return to SET-UP A mode.

Once these steps have been performed. SET-UP features which had been temporarily stored will now be stored on a fixed basis.

Recalling SET-U P Features
The temporarily stored SET -U P feature settings may differ from the settings which
have been stored on a fixed basis. If you wish to return to the fixed settings.
perform the recall operation as follows:

NOTE
When a recall operation is
performed the contents of the
screen are destroyed.

Place the terminal in SET-UP mode.

Press the SHIFT and R keys simultaneously. The screen will clear and
the message "wait" will appear in the upper-left corner of the screen.
After a brief wait the terminal will return to SET-UP A mode.

OPERATOR INFORMATION 13

Resetting the Terminal
The VT100 may be reset from the keyboard. When the terminal is reset, the terminal memory is cleared and the self-test program is run as if the terminal power
switch had been turned OFF and then back ON. To reset the terminal:

Place the terminal in SET-UP mode.

Press the 0 key on the main keyboard. The VT100 will be reset the
power on self-test will be run, and the terminal will set according to the
fixed SET -U P features.

NOTE
When a reset operation is performed the contents of the
screen are destroyed and any
options present iTiay be affected.

PART 3
DEFINITION
OF EACH
SET-UP FEATURE
This section describes each SET-UP feature in detail (in alphabetical order) and
states how each feature affects the terminal.
ANSI/VT52 Mode
The VT100 terminal follows two different programming standards - American
National Standards Institute (ANSI) and VT52. In ANSI mode, the VT100 will
generate and respond to coded sequences per ANSI standards X3.41-1974 and
X3.64-1977. In VT52 mode, the VT100 terminal is compatible with previous
DIGITAL software using the VT52 video terminal. Both ANSI and VT52 modes are
outlined in the programmer's section of this manual.

NOTE
Unless otherwise stated, entering SET-UP mode and
changing features does not
result in the loss of data displayed on the screen.

ANSWERBACK Message
Answerback is a question and answer sequence where the host computer asks the
terminal to identify itself. The VT100 answerback feature provides the terminal
with the capability to identify itself by sending a message to the host. The entire
answerback sequence takes place automatically without affecting the screen or
requiring operator action. The answerback message may also be transmitted by
typing CTRL- BREAK.
AUTO REPEAT
The auto repeat feature allows a key to be automatically repeated at the rate of
about 30 characters per second when the key is held down for more than one-half
second. The auto repeat feature affects all keyboard keys except the following:
SET-UP
ESC
NO SCROLL

TAB
RETURN
CTRL and any key

AUTO XON/XOFF
The VT100 is capable of automatically generating synchronizing codes XON (DC1)
and XOFF (DC3). The XOFF code is used to stop the transmission of data from the
computer to the terminal; the XON code is used to resume transmission. With the
feature enabled. the VT100 will generate the XOFF code when one of the following events occur:
1.
2.
3.
4.

The internal buffer is nearly full
The NO SCROLL key is pressed
The terminal is placed in SET-UP mode
CTRL- S is pressed.

NOTE
The VT100 will always stop
transmission when an XOFF
(DC3) code is received and
will resume transmission
when an XON (DC1) code is
received regardless of the
AUTO XON/XOFF feature setting.

OPERATOR INFORMATION

When either the buffer empties. the NO SCROLL key is pressed again. the terminal
is taken out of SET -U P mode. or CTR L - Q is pressed. the VT100 will transmit
the XON code to resume transmission from the computer to the terminal.
If the host computer software does not support the XON/XOFF codes. data sent
during buffer full conditions. or when the terminal is in SET-UP mode. may be lost.
BITS PER CHARACTER
This feature allows the terminal to transmit and receive either 7 - or 8-bit characters. When set for 8-bit operation. bit 8 is set to a space (or 0) for characters
transmitted and is ignored for all characters received.

NOTE
When changing from 80 to
132 character per line mode
or vice-versa, the current contents of the screen are lost.
The use of double-width characters reduces the number of
characters per line by half.

CHARACTERS PER LINE
The VT100 is capable of displaying either ~O or 132 characters per line. In the 80
character per line mode. the screen is 80 characters wide by 24 lines high. In the
132 character per line mode. the screen is 132 characters wide by 14 lines high
(24 lines if the VT100 is equipped with the Advanced Video Option). In the 132
character per line mode. the displayed lines are physically the same width as in the
80 character per line mode but the characters are more compact.
CURSOR
The VT100 offers a choice of two cursor representations to indicate the "active
position". or where the next character will be placed on the screen. The cursor may
be displayed as either a blinking underline (-) or a blinking block (.). The cursor
selection may perform an additional function; see the SGR escape sequence definition in Chapter 3.
INTERLACE
This feature is used for high resolution options. To reduce screen flicker the interlace feature should be turned off if such an option is not installed.
KEYCLICK TONE
The keyclick is a tone which is generated every time a code transmitting key is
pressed. The keyclick may be turned on or off to suit the operator's needs. However. research and experience has shown that an operator is more accurate when
there is an audible feedback from the keyboard.
Like the bell tone. the keyclick volume is not adjustable.
LINE/LOCAL
The LINE/LOCAL feature allows the operator to easily place the terminal in either
an ON-LINE or a LOCAL (off-line) condition. When the terminal is on-line (the
keyboard ON-LINE indicator is ON) all characters typed on the keyboard are sent
directly to the computer and messages from the computer are displayed on the
screen. In the LOCAL condition (the keyboard LOCAL indicator is ON). the terminal
is electrically disconnected from the computer; messages are not sent to or received from the computer; and characters typed on the keyboard are echoed on
the screen directly.
MARGIN BELL
The margin bell feature is much the same as the bell in a typewriter. If the cursor is
eight characters from the end of the current line while typing. the VT100 sounds a
tone to alert the operator.

OPERATOR INFORMATION

NEW LINE
The new line feature enables the RETURN key on the terminal to function like the
RETURN key on an electric typewriter. When the new line feature is enabled,
pressing the RETU RN key generates the carriage return (CR) and line feed (LF)
codes. When a line feed code is ieceived, the code is interpreted as a carriage
return and line feed.
When the new line feature is disabled, the R ETU RN key generates only the CR
code; an LF code causes the terminal to perform a line feed only.
PARITY
Parity, when enabled, checks for correct data transmission. !f a transmission error
occurs, the VT100 can detect it and indicate its presence by placing a checkerboard character ( :::::: ) on the screen in place of the character with the error. The
parity sense feature determines if the parity is even or odd. When parity is disabled, no parity bit is transmitted or received.
PARITY SENSE
The parity sense feature defines which of the two methods of parity checking, odd
or even, is being used by the VT100. If the parity feature is on, the terminal's parity
sense must be matched to the parity the computer is sending. If the parity sense
features do not match, most characters sent to the computer will be rejected even
though the character was received correctly by the VT100. If a parity incompatibility occurs, the checkerboard character ( :::::: ) will be shown on the screen
in place of the received character.
POWER
During the initial installation, the terminal display must be set to the power line
frequency. In the U.S. this is set to 60 hertz.
RECEIVE SPEED
The receive speed must be set to match the computer transmit speed. The VT100
is capable of receiving at anyone of the following preselected speeds: 50, 75,
110,134.5,150,200,300,600, 1200,1800,2000,2400,3600,4800,9600,
19,200 baud.
The receive speed is independent of the transmit speed; the terminal may receive
data at one speed and transmit data at a different speed.
SCREEN BACKGROUND
The screen background feature of the VT100 allows the operator to determine the
background of the screen. In the normal screen mode, the display contains light
characters on a dark background; in the reverse screen mode, the display contains
dark characters on a light background.
SCREEN BRIGHTNESS
Unlike most video terminals, the VT100 does not contain switches or knobs to
adjust screen brightness. Instead, the VT100 electronically controls the screen
brightness. This feature eliminates the high failure rate of mechanical controls and
still allows the operator to select the desired level of brightness for maximum
comfort under varied lighting conditions. This setting may be saved like any other
feature in the terminal.

NOTE
If double line feeds occur consistently, turn this feature off
since the computer is already
performing this function auto-

matically.

NOTE
If the parity feature is turned
off, the parity sense selection
will be disregarded.

OPERATOR INFORMATION

SCROLL
Scrolling is the upward or downward movement of existing lines on the screen to
maximum of six lines of data make room for new lines at the bottom or top of the screen. It can be performed in
per second to be added to the two ways: jump scroll or smooth scroll. In jump scroll mode. new lines appear on
screen. The Auto XON/XOFF the screen as fast as the computer sends them to the terminal. At the higher baud
feature must be enabled and rates, the data is very difficult to read due to the rapid movement of the lines. In
supported by the host comsmooth scroll mode. a limit is placed on the speed at which new lines of data may
puter to ensure that data is
not lost when smooth scroll be sent to the terminal. The movement of lines occurs at a smooth steady rate
allowing the data to be read as it appears on the screen.
mode is enabled.
NOTE
Smooth scroll mode allows a

TABS
Just like a typewriter, the VT100 can jump or tab to preselected points on a line.
These tab stops may be individually changed, or totally cleared and then set.
TRANSMIT SPEED
Transmit speed must be set to match the computer receive speed. The VT100 is
capable of transmitting at anyone of the following preselected transmit speeds:
50,75,110.134.5,150,200,300,600, 1200, 1800,2000.2400,3600,4800,
9600. and 19.200 baud.
Transmit speed is independent of receive speed; the terminal may transmit data at
one speed and receive data at a different speed.

WRAPAROUND
When this feature is enabled, the 81 st or 133rd character (depending upon the
line size selected) inserted on a line is automatically placed in the first character
NOTE
position
of the next line. If the wraparound feature was not enabled. the 81 st or
The use of double-width characters reduces the number of 133rd character and all following characters would be overwritten into the last
character position of the current line.
characters per line by half.

(shifted)

The VT100 contains character sets for the U.S. and the United Kingdom. The
difference between the two character sets is one character, the # or £ symbol.
When the standard U.S. character set is selected, the uppercase 3 key on the main
keyboard displays the # character. The £ character is displayed when the U. K.
character set is selected.

PART 4
SELF-TESTING
THE VT100
A self-test mode is built into the VT100 that automatically. or on command, tests
the condition of the terminal should a fault be suspected. The self-test program
checks the following items:
Advanced Video Memory (if option is installed)
Nonvolatile Memory (NVR)
I nternal Memory
Keyboard

OPERATOR INFORMATION

This test is performed automatically whenever the terminal is turned on.

Self-Test Error Codes
There are two broad categories of errors: fatal and nonfatal.
Fatal errors cause the terminal to immediately stop all operations. No intelligible
information is displayed on the screen; however, the screen most likely contains a
random pattern of characters. The only error indication (in addition to the random
characters) is a possible' error code displayed on the programmable keyboard
LEOs, L 1-L4; however, no terminal function, including the lighting of LEOs, is
guaranteed if a fatal error is found.
Nonfatal errors do not halt the terminal processor. Instead, the terminal is forced to
LOCAL mode and an error code character is displayed in the upper-left corner of
the screen.

lVOTE
The loopback and EIA modem
control tests are not performed on power-up; they
must be invoked separately
with the proper escape sequence. See the programmer's section for further
information on these tests.

There are five types of nonfatal errors:
1. (AVO) Advanced Video Option data RAM

2. (NVR) Nonvolatile data RAM checksum error

3. (KBD) Keyboard missing or malfunction
4. (Data) Data loopback error
5. (EIA) EIA modem control error
Table 1-3 shows the possible nonfatal error characters that may appear on the
screen and the failure represented by each character.

;0I1;aijibtj~·ltl!·;I:~::'n':~~i;p~t&btEtd. '.::: .' :!: :;: ie ;. et..~~eJ; :'; .::;: ;:. :. ~t.lt .[)~tected :~;: ·
. iDi~Plaveii: :A.VO· NvR f<BDData EtA
. 'Olsplayed: AVO NVR KBD Dafa EtA

...x.

• ~)(,;•., "4

X
X

X
X
X
X
X

."
6
7

8
,,9

".",x

X
X

X
X
X

<
X

>
?

X
X

X
X
X
X

F
G
H
t

J
K
l
M
N
0

X
X

"'''X

X
X

X
X
X
X
X

Table 1-3
Nonfatal Displayed
Error Codes

OPERATOR INFORMATION

PART 5
WHAT TO DO
IN THE EVENT
OF A PROBLEM
If it appears that there is a problem in the terminal. you should initiate the powerup self-test program. This test will help to determine if the problem lies in your
terminal or in some other part of the computer system. Table 1-4 describes the
items an operator can check prior to making a service call.

Table 1-4
Problem Checklist
"

~ ,,'

AC powercord.is notpiuggedintbwalto'utlet; plug in cord.
the power ~wit~h is set to. ON.
AC power.cordis not plugged into theterminaJ;.p~ug in cord.
Power is not coming from the wall outlet; check outlet with'
a knownworklngelectrical device (such as a lamp). If ho
power. call your electrician.
AC line fuse blown; turn terminal OFF and have the fuse
replaced. (See Figure 1-2 for location.)
No keyboard response

Keyboard cable not plugged into monitor; plug in keyboard
cable.
KBD LOCKED indicator on; computer has turned the keyboard off. The KBD LOCKED conditions may be cleared by
entering and exiting the SET-UP mode. If this condition persists. check with the host computer software people for a
possible operating error.
Perform the self-test operation.

Garbled or Error (::::~) Characters

Incorrect SET-UP feature selection; correct the SET-UP features. Suggested SET-UP features which may be in error:
ANSIIVT52 mode
Auto XON/XOFF
Bits per character
Parity
Parity sense
Receiver speed
Transmit speed
Perform the self-test operation.
Theterminalhas i;lad.difficulty in{e~ing. or \Nriting the SETUP features stored' in non-volatile' memory. Cl;leck the feature settings and perform the save; operation:
Perfom:' the self-test Operation.

CHAPTER 2

I N ST A L LA T ION,
INTERFACE INFORMATION,
AND SPECIFICATIONS
SITE CONSIDERATIONS
The design of the VT100 terminal (Figure 2-1) will normally pose few constraints
on selecting a place in which to install the terminal. In most cases, any environment suitable to the terminal operator will be a satisfactory environment in which
to operate the terminal. Extremes of temperature and humidity should be avoided.
A summary of VT100 guaranteed operating conditions is found at the end of this
section.
UNPACKING AND INSTALLATION
The VT100 shipping carton contains the following items:
VT100 monitor
VT100 detached keyboard
VT 100 power cord
VT100 SET-UP label
VT100 User's Guide

INSTALLATiON

INSTALLATION, INTERFACING AND SPECIFICATIONS

· E::J

8.9 CM
13 1/2 IN.I

4.8 CM

(1 7/8 IN.)

-I

11.1CM
I
1--(4 3/8 IN)-t

1.--24.5 CM (9 5/8 IN.)----I
te-----30.5 CM (12 I N . ) - - - - - - - i

20.32 CM (8 IN)

1 - - - - - - - 3 6 . 2 CM (14 1 / 4 I N ) - - - - - - - i
t e - - - - - - - - - - - - - 51.4 -CM (20 1/4 IN.*) - - - - - - - - - - - - - - - . . j

y.
Figure 2-1
VT100 Terminal Dimensions

41.3 CM (16 1/4 IN.)

45.7 CM (18 IN.)
* MEASUREMENT TAKEN WITH THE KEYBOARD PLACED FLUSH TO FRONT OF TERMINAL UN DER UNDERCUT.
MA-1991

INSTALLATION, INTERFACING AND SPECIFICATIONS

To install the VT100 perform the following steps:
1.

Remove the VT100 from the shipping carton and place it in the desired
work area,

Place the keyboard in front of the terminal and plug the keyboard coiled
cord into the keyboard receptacle located on the rear of the terminal
(Figure 2-2).

Verify that the power selector switch shows the correct wall outlet
voltage (115 V is standard in the U.S.) and the power switch is off.

Connect the power cord to the power cord receptacle on the rear of the
terminal and plug the other end of the power cord into a nearby wall
outlet.

Connect the communications cable to the appropriate communications
receptacle.

Turn the power switch on. The terminal will now automatically perform
the power-up self test and either the ON LINE or LOCAL light located
on the keyboard will be turned on. After approximately one minute the
cursor will be visible in the upper-left corner of the screen. If any other
indication is shown, refer to Part 5 of the operator information chapter.

Set the desired SET-UP features as outlined in the operator's section of
this manual.

Once the installation setup procedure is complete, record the SET-UP
features selected on the VT100 SET-U P label and attach the label to
the underside of the keyboard.
CAPTIVE
SCREWS (4)

ACCESS
COVER

EIA
COMMUNICATIONS
CONNECTOR
EXTERf'JAL VIDEO
INPUT CONNECTOR
EXTERNAL VIDEO
OUTPUT CONNECTOR
MAIN FUSE

POWER SWITCH

MODEL
SERIAL
NUMBER LABEL

CONNECTOR

" " OPTIONAL 20mA
"COMMUNICATION
CONNECTOR

SELECTOR
SWITCH

Figure 2-2

CONNECTOR
MA-1987

VT100 Rear View

INSTALLATION, INTERFACING AND SPECIFICATIONS

USER MAINTENANCE
The keyboard keys are the only moving parts of the terminal and require no preventive maintenance by the owner. The VT100 surfaces may be cleaned with soap
and water or any mild detergent. Cleaners with solvents should not be used.
The VT100 packaging is not meant to be weatherproof; there are several openings
in the case through which liquids, coins, paper clips, and other objects can fall.
Such objects would disturb the electronic operation of the terminal if they came
into contact with the circuitry. For this reason, avoid putting drinks and metal
objects on the top of the terminal, or using excessive water to clean the terminal.
Rubbing the keys with a dry or barely moist cloth should suffice to clean them. Do
not remove the keycaps to clean them more thoroughly; damage may result to the
switch contacts if they are replaced incorrectly.
Keep the ventilation slots clear. Blocking these slots by placing objects on top of or
under the VT100 may cause the terminal to overheat.

INTERFACE
INFORMATION
EIA Interface

Table 2-1
EIA RS-232-C
Connector Signals

The basic VT100 operates on full duplex, asynchronous communication lines. The
terminal interfaces to the line with a 25-pin connector mounted on the back of the
terminal which meets the requirements of EIA specification RS-232-C. Table 2-1
summarizes the EIA connector signals; the following paragraphs explain each signal as used in the basic VT100.

Pin
Number

1
2
3

4
5
6

7
8
9
10
11
12

Description
Protective ground
Transmitted data
Received data
Request to send
Clear to send
Data set ready
Signal ground (common return)
Carrier detect
(not used)
(not used)
Same as pin 19
Speed indicator
(secondary .carder detect)
(not used} .

Pin
Number

14
15
16

17
18
19

Description
(not used)
Transmit clock
(not used)
Receive clock
(not used)

20
21
22

Speed select
(secondary request to send)
Data terminal ready
(not used)
Ring indicator

23
24
25

Same as pin 19
(not used)
(not used)

Protective Grou nd - Pi n 1
This conductor is electrically bonded to the VT100 chassis. Use of this conductor
for reference potential purposes is not allowed.
Transmitted Data (from VT100) - Pin 2
The VT100 transmits serially encoded characters and break signals on this circuit.
which is held in the mark state when neither characters nor break Signals are being
transmitted.

INSTALLATION, INTERFACING AND SPECIFICATIONS

Received Data (to VT100) - Pin 3
The VT100 receives serially encoded characters generated by the user's equipment on this circuit.
Request to Send (from VT100) - Pin 4
Asserted at all times when terminal is powered up.
Clear to Send (to VT'OOj - Pin 5
Ignored at all times.
Data Set Ready (to VT100) - Pin 6
Ignored at all times.
Signal Ground - Pin 7
This conductor establishes the common ground reference potential for all voltages
on the interface. It is permanently connected to the VT100 chassis.
Carrier Detect (to VT100) - Pin 8
Ignored at all times.
Speed Select (from VT100) - Pins 11, 19, and 23
This signal is alternately called Secondary Request to Send. The basic VT100
maintains this line in the asserted state at all times.
Speed Indicator (to VT100) - Pin 12
This signal. alternately called Secondary Carrier Detect is ignored at all times.
Transmission Clock (to VT100) - Pin 15
Ignored at all times.
Receive Clock (to VT100) - Pin 17
Ignored at all times.
Data Terminal Ready (from VT100) - Pin 20
Data Terminal Ready is asserted at all times except under the following conditions:
1.
2.
3.

Terminal is not powered up
Terminal is in LOCAL mode
The 3.5 second interval following the pressing of SHIFT-BREAK.

Ring Indicator (to VT100) - Pin 22
Ignored at all times.

Electrical Characteristics
VT100 Output Voltages - On signals designated "from VT100," the mark, or
unasserted state, is -6.0 V to -12.0 V; the space, or asserted state, is +6.0 V
to +12.0 V.
VT100 Input Voltages - On signals designated "to VT100," -25.0 V to +0.75 V
or an open circuit is interpreted as a mark or unasserted state, and +25.0 V to
+2.25 V is interpreted as a space or asserted state. Voltages greater in magnitude
than ±25 V are not allowed. These levels are compatible with EiA STD RS-232-C
and CCITT Recommendation V.28.

INSTALLATION. INTERFACING AND SPECIFICATIONS

Optional 20 mA
Current Loop Interface
In most current loop applications, the VT100 will be connected in a passive configuration - that is, current is supplied to the VT100. In this mode, the t'ransmitter
and receiver are both passive, both optically isolated, and the transmitter goes to
the mark state when power is turned off.
Conversion from active to passive (or vice versa) requires moving a slide switch.
In active mode either the transmitter or the receiver or both may be connected so
that the VT100 sources the 20 mA of current. In active mode isolation is not
present and the transmitter will go to the space state when power to the VT100 is
turned off,
Figure 2-3 shows the 20 mA current loop interface connector mounted to the
access cover and the individual pin assignment.

Electrical Characteristics
The electrical characteristics of the 20 mA current loop interface are shown below:
Transmitter

Receiver

Min
Open circuit voltage
5.0 V
Voltage drop marking Spacing current
Marking current
20 mA

Max
50V
4.0V
2.0mA
50 rnA

Min
Voltage drop marking Spacing current
Marking current
15rnA

Max
2.5V
3.0mA
SOmA

In addition to the above specifications for passive operation, active mode will place
the transmitter or receiver in series with a source of 17 V ±5 percent and 660
ohms.

TERMINAL
ACCESS
COVER

PIN ASSIGNMENTS
, - TEST NEGATIVE
2 - TRANSMIT 3 - RECEIVE5 - TRANSMIT +
7 - RECEIVE
8 - PROTECTIVE GROUND

Figure 2-3
20 mA Current Loop Interface

o
o

20mA CURRENT
LOOP CONNECTOR

0000.0

123

MA-1992

INSTALLATION, INTERFACING AND SPECIFICATIONS

External
Video Connections
In addition to the EIA interface, the VT100 is also capable of easily interfacing to
external video devices. The video devices may act either as a slave to the VT100
when connected to the composite video output or provide synchronized video to
the VT100 video section when connected to the video input. The external video
connectors are the two female BNC connectors located on the back of the terminal
just below the EIA connector. The upper connector, J8, is the video input while the
lower connector, J9, is the video output.
Composite Video Output (J9)
The composite video output provides RS 170-like output (see note) generated by
combining the video signal with a composite sync signal. This output contains all
video data appearing on the VT100 screen except that video which comes from
J8. The output has the following nominal characteristics. (Refer to Figure 2-4.)

1.
2.
3.
4.

Output impedance
75 ohms, dc-coupled
Sync level = 0 V
Black level = approximately 0.3 V when loaded with 75 ohms
White level
approximately 1.0 V with a 75 ohm load
The composite sync waveform conforms to EIA RS 170 standards. The
vertical interval is composed of six equalizing pulses, six vertical sync
pulses, and six more equalizing pulses. The timing is as follows:

Equalizing pulse width
Vertical pulse width
Horizontal pulse width
Horizontal blank width

= 2.33 JiS ±50 ns
=

11.84 JiS ±50 ns/80 column mode
_ 12.34
{=
JiS ±50 ns/132 column mode

Front Porch

27.28 JiS ±200 ns

= 4.71 JiS ±50 ns

1.54 JiS ± 50 ns

Video Input (J8)
An analog signal applied to the video input will be "ORed" with the internal video
signal in such a way that the beam intensity at any point on the screen will
correspond to the intensity of that signal which would tend to make the beam
brighter at that point. A video signal on this input affects only the internal screen and
does not appear on the composite video output. This input has the following nominal
characteristics.
1.
2.
3.
4.

Input impedance = 75 ohms, dc-coupled
Black level
0 V
White level = 1.0 V
Maximum continuous input = ±2.0 V

The external video source must be synchronized to the VT100; it may do this by
referencing the composite sync on the composite video output. This means that
the VT100 video input will not synchronize with any composite video source including the composite video output of another VT100.

NOTE

The use of dc-coupling is
not in strict agreement with
RS170. To agree with RS170
the output load requires a 10
J.LF capacitor in series with
the output. Failing to do so,
the 2 mA de short circuit current requirement is violated.
This presents no problem
with most monitors which are
in fact ac-coupled.

INSTALLATION. INTERFACING AND SPECIFICATIONS

EVEN FIELD:

VERTICAL BLANKING INTERVAL

1+-----------------LAST DiSPLAYED SCAN OF
PREVIOUS FIELD

{

50 Hz NON-INT = 22 SCANS}
50HzINT
=_22 SCANS
50 Hz NON-I NT = 75 SCANS ---~
50 Hz INT

1.0 V

FIRST OF 240 DISPLAYED
SCANS IN EVEN FIELD

= 74 SCANS

50 Hz NON-INT = 2 SCANS
50 Hz INT
= 2 SCANS
{ 50 Hz NON-INT = 25 SCANS
50 Hz INT
= 24 SCANS

~~~~

1\J\

TIME_

START OF
EVEN FIELD

ODD FIELD:
: VERTICAL BLANKING INTERVAL

FIRST OF 240 DISPLAYED
SCANS IN ODD FIELD

50 Hz INT = 2.5 SCANS
{ 50 Hz INT = 24.5 SCANS

TIME-

-...j

H BLANK {11.84 f.ls ± 50 ns /80 COLUMN
12.34 f.ls ± 50 ns / 132 COLUMN

BRIGHT = 1 . 0 0 V _ §
NORMAL = .79 V _
DIM = .54V-

BLACK = .29 V SYNC = 0.00 _
FRONT PORCH = 1.54 f.ls ± 50 ns

J------~

HSYNC=4.71 f.l s ±50ns

.---If

~Q = 2.33 f.lS ± 50 ns -...\ I-

I,--~n

-.j

j.-V

IL
SYNC = 27.28 /.IS
± 200 ns

H PERIOD = 53.56 /.IS ± .01%

NOTES

-IN NON-INTERLACED OPERATION THE EVEN FIELD IS REPEATED CONTINUOUSLY, AND THE ODD FIELD IS NOT USED

Figure 2-4
Composite Video Output

-IN'THE INTERLACED OPERATION THE EVEN FIELD ALTERNATES WITH THE ODD FIELD.
-ALL FIELDS CONTAIN 240 DISPLAYED SCANS.

VT100
SPECIFICATIONS
Dimensions

Weight

Monitor

Height: 36.83 em (14.5 inch)
Width: 45.72 em (18 inch)
Depth: 36.20 em (14.25 inch)

Keyboard

Height: 8.89 em (3.5 inch)
Width: 45.72 em (18 inch)
Depth: 20.32 em (8 inch)
Minimum table depth: 51.4 em (20.25 inch)

Monitor

13.6 kg (30 Ibs)

Keyboard

2.0 kg (4.5 Ibs)

Shipping Weight

18.6 kg (41 Ibs)

INSTALLATION, INTERFACING AND SPECIFICATIONS

Operating

Temperature: 10° to 40° C (50° to 104° F)
Relative humidity: 10% to 90%
Maximum wet bulb: 28 0 C (82 0 F)
Minimum dew point: 2 0 C (36 0 F)
Altitude: 2.4 km (8,000 ft)

N on- Operati ng

Temperature: -40 0 to 66 0 C (-40 0 to 151 0 F)
Re!ative humidity: a to 95%
A!titude: 9.' km (30,000 ft)

Line Voltage

90-128 V RMS single phase, 2 wire
180-256 V RMS single phase, 2 wire
(switch-selectable)

Line Frequency

47-63 Hz

Current

2.2 A RMS maximum at 115 V RMS
1.1 A RMS maximum at 230 V RMS

Input Power

250 VA apparent 150 W maximum

Current limiting

3 A normal blow fuse

Power cord

detachable, 3 prong, '.9 m (6 ft)

CRT

12 inch diagonal measure, P4 phosphor

Format

24 lines X 80 characters or 14 lines X 132 characters (selectable)

Character

7 X 9 dot matrix with descenders

Character size

3.35 mm X 2.0 mm (0.132 inch X 0.078 inch) in
80 column mode
3.35 mm X 1.3 mm (0.132 inch X 0.051 inch) in
132 column mode

Active Display Size

202 mm X 115 mm (8 inch X 4.5 inch)

Character Set

96 character displayable ASCII subset (upperand lowercase, numeric and punctuation)

Cursor type

Keyboard-selectable, blinking block character or
blinking underline.

General

83-key detachable unit with a 1.9 m (6 ft) coiled
cord attached

Key Layout

65-key arrangement and sculpturing similar to
standard typewriter keyboard with an 18-key
auxiliary keypad.

Auxiliary Keyboard

18-key numeric pad with period, comma, minus.
enter, and four general-purpose function keys

Visual Indicators

Seven LEOs; three LEOs dedicated to ON LINE,
LOCAL and KBD LOCKED. four LEOs user-programmable.

Environment

Power

Display

Keyboard

INSTALLATION, INTERFACING AND SPECIFICATIONS

Communication

Audible Signals

Key-click: sound simulates typewriter.
Bell: 1) sounds upon receipt of BEL code;
2) sounds eight characters from right
margin (keyboard-selectable),
Multiple bell: sounds upon detection of error in
SET-UP save or recall operation.

Type

EIA

Speeds

Full duplex: 50, 75, 110 (two stop bits), 134.5.
150.200,300,600.1200,1800.2000.2400,
3600. 4800. 9600, 19,200

Code

ASCII

Character Format

Asynchronous

Character Size

7 or 8 bits; keyboard-selectable. (Note: If 8-bit
character is selected. eighth bit is always space.)

Parity

Even. odd. or none - keyboard-selectable

Synchronization

Keyboard-selectable via automatic generation of
XON and XOFF control codes.

HOW TO ORDER
HARDWARE
DOCUMENTATION
The following VT100 Video Terminal hardware manuals can be purchased from
DIGITAL's Accessory and Supplies Group.
Part No.
EK-VT100-UG
EK-VT1 OO-J 1
EK-VT1 00-TM
EK-VT100-IP
MP-00633

Title
VT100 User Guide
VT100 Mini Maintenance Manual
VT100 Technical Manual
VT100 Illustrated Parts Breakdown (I PB)
VT100 Print Set

All purchase orders for hardware manuals should be forwarded to:
Digital Equipment Corporation
Cotton Road
Nashua,N.H.03060
Supplies and Accessories Group (P086)
Purchase orders must show shipping and billing addresses and state whether a
partial shipment will be accepted.
All correspondence and invoicing inquiries should be directed to the above address.

PROGRAMMER INFORMATION

CHAPTER 3
PROGRAMMER INFORMATION
The VT100 terminal normally performs a two-part function. It is an input device to
a computer - information entered through the keyboard is sent to the computer. It
is simultaneously an output device for the computer - that is, data coming in from
the computer is displayed on the video screen. Figure 3-1 shows the data flow.
This section of the user's manual discusses data flow between the VT100 and the
host. I ncluded are the codes generated by the keyboard; the transmission protocol
followed by the terminal; and the actions and reactions of the terminal to control
functions in both ANSI and VT52 modes of operation.

VT100

r---------,
I
I

I
I

---------'

COMMUNICATION
LINES

MA-1994

Figure 3-1
Terminal Data Flow

PROGRAMMER INFORMATION

••••
••••
••••

···1
...
Figure 3-2 VT100 Keyboard

THE KEYBOARD
The VT100 uses a keyboard with a key arrangement similar to an ordinary office
typewriter, as shown in Figure 3-2. In addition to the standard typewriter keys the
VT100 keyboard has additional keys and indicators used to generate control sequences, cursor control commands, and to show the current terminal status.
LE D Indicators
The keyboard has seven light emitting diodes (LEOs) of which two are committed
to the complementary ON-LINE/LOCAL function. The power on condition is implicitly shown by one of the two LEOs being on; that is, if the keyboard is connected
and power is on, one of these LEOs will be on.
A third LED indicates a "keyboard locked" condition. In this condition the keyboard
has been "turned off' automatically by the terminal due to a full buffer or by the
host through the transmission of an XOFF to the terminal.
The four remaining LEOs are programmable and can be assigned any meaning for
specific applications. The code sequences to turn these LEOs on or off are discussed later in this chapter .
•

SET-UP

The SET-U P key is at the upper-left corner of the main key array. Operations
performed in SET-UP mode can be stored in nonvolatile memory (NVR) so that
turning the terminal power off does not. by itself, alter the terminal configuration.
The procedures to change the SET-UP features are provided in the operator's
information section of this manual. Those SET-UP features which may be modified
by the host are listed in Table 3-1 and described in detail under the escape sequences.
Keyboard Operation
The operator uses the keyboard to transmit codes to the host. Some keys transmit
one or more codes to the host immediately when typed. Other keys such as CTRL
and S H I FT do not transmit codes when typed, but modify the codes transmitted
by other keys. The code-transmitting keys cause the terminal to make a clicking
sound to verify to the operator that the keystroke has been processed by the
terminal. If two code-transmitting keys are pressed together, two codes will be
transmitted according to the order in which the keys were typed. The terminal will
not wait for the keys to be lifted, but will transmit both codes as soon as possible

PROGRAMMER INFORMATION

after the keys are first typed. If three such keys are pressed simuitaneousiy, the
codes for the first two keys are transmitted immediately; the code for the third will
be transmitted when one of the first two keys is lifted.
Alphabetic Keys - The VT100 will tiansmit the lowercase code unless either or
both of the SHIFT keys are down, or unless the CAPS LOCK key is down. Pressing the CAPS LOCK key will lock only the 26 alphabetic keys in the shifted
(uppercase) mode. Table 3-2 shows the codes generated by the alphabetic keys.

Table 3-1
Machine States

... :·:'Atito· R~P,eat,. : .

. :' AUTO XONXOFF' •
.•. Bits o~rcharacter ;.
l"'

. 1'"\

'"'

,,.

Cha~~cte.rsper lina

Cursar..

CtJr~r key mode
Interlace

··New.Line.
Keyclick
.; Matgin' D~H'
o.rigin mode

Parity
Parity sense

'~T<~y

A
B

C
0
E
F

G
H

J
K
L

Uppercase.
Code (octal)

LO)Narcase
C.ode: (octal)

10.1
10.2
10.3
10.4
10.5

'141
142
143
144
145

10.6
10.7
110.
111
112

146
147
150.
151
152

113
114
115

153
154
155

.Key
N
0.
P
Q

S
T
U
V
W

X
Y
Z

.uR~.:caS~
code (octal)

..
'" ,Lo)Narcasa..

Code'IQCia.~r""*·

1.17
120.·
121
122

156
157 .
160.
161
162

123
124
125
126
127

163
164
165
166
167

130.
131
132

170.

116

171
172

Table 3-2
Alphabetic Key Codes

PROGRAMMER INFORMATION

Nonalphabetic Keys - Each of the nonalphabetic keys can be used to generate
two different codes. One code will be generated if neither SHIFT key is pressed.
The other code will be generated if either or both of the SH I FT keys are down.
Unlike the SHIFT LOCK key of a typewriter, the CAPS LOCK key does not affect
these keys; it affects only the alphabetic keys. Table 3-3 shows the nonalphabetic
keys and the codes they generate.

Table 3-3
Nonalphabetic Key Codes

;;Lowerease'
. ; Character

' 'Neither SHIFT
"~yDoWii\"
tOctaJ)

OEH

.2
,3

062
063
064
065

'4
5

066
067
070
071
060

, (apostrophe)

055
075
133
073
047

8
9

, (comma)
. (period)
I

054
056
057
134
140
135

Either Or Both
,
SH IFT'Keys Dowh'
(Octal)

Uppercase
Character

041'
100
043
044
045

#Qr£
$

%
1\
&

136
046
052
050
051
137
053
173
072
042

+
{

<
>

074
076
077
174
176
175

Function Keys - There are several keys on the keyboard which transmit control
codes. Control codes do not produce displayable characters but are codes for
functions. If these codes are received by the terminal. the VT100 will perform the
associated function as shown in Table 3-4.
Table 3-4
Function Key Codes
Key

Octal Value of
Code Sent or
Received by VT100

Action The Terminal Would
Take if Host Sent That Code

RETURN*

015

Carriage return function

LINEFEED

012

Line Feed

BACKSPACE

010

Backspace function

TAB

011

Tab function

SPACE BAR

040

Deposit a space on the scteen erasing what was
'
there before.

ESC

033

The initial delimiter of an escape sequence - interpret .the following character string from' tne host
as a' comm'and, rather than displaying it.

DELETE

,177

Ignored by the VT100,

* The RETURN key can be redefined so that it issues 015 012
8,

New Line feature in SET~UP mode provides this capability.

(carriage return - linefeedl. The

PROGRAMMER INFORMATION

NO SCROLL - When the NO SCROLL key is pressed it generates a single XOFF
code, inhibits further scrolling and freezes the screen. When pressed again the
same key generates XON. In practice, if the software recognizes XOFF, the host
will stop transmitting until the NO SCROLL key is pressed again to allow scrolling.
If the XOFF/XON feature is disabled (SET-UP function) the NO SCROLL key
causes no action.
BREAK - Typing the BREAK key causes the transmission iine to be forced to its
ZeiO state for 0.2333 seconds ±10 percent. If either SHIFT key is down, the time
is increased to 3.5 seconds ± 10 percent. Data Terminal Ready is also deasserted
during this interval. At the conclusion of the 3.5 second interval Data Terminal
Ready will again be asserted.
The SHIFT and BREAK keys typed together provide the long-break-disconnect
function. Used with properly configured modems with RS-232-C levels, it will
cause both the local and remote data sets to disconnect. For modems that are
connected via the 20 mA current loop, issuing the long space may disconnect the
remote data set only.
The CTRL and BREAK keys typed together cause the transmission of the
answerback message.
The BREAK key does not function when the VT100 is in LOCAL mode.
Auto Repeating - All keys will auto repeat except: SET-UP, ESC. NO SCROLL,
TAB, RETURN, and any key pressed with CTRL. Auto repeating works as follows: when a key is typed, its code(s) is sent once, immediately. If the key is held
down for more than 112 second, the code(s) wili be sent repeatedly at a rate of
approximately 30 Hz (less if low transmit baud rates are used) until the key is
released.
CTRL (Control) - The CTRL key is used in conjunction with other keys on the
keyboard to generate control codes. If the CTRL key is held down when any of the
keys in Table 3-5 are typed, the code actually transmitted is in the range
000 8 -037 8 .
Table 3-5
Control Codes Generated

. Space Bar"
A;,

B, '
C

o
E
F
G
H

I
J

K
,L
M
N

PROGRAMMER INFORMATION

Cursor Control - The keyboard also contains four keys labeled with arrows in
each of four directions. These keys transmit control sequences. If the host echoes
these control sequences back to the terminal. the cursor will move one character
up. down. right. or left. Table 3-6 shows the control sequences generated by each
key.
Table 3-6
Cursor Control Key Codes

vr52~: ; AN~IM<).,~nd'a.~$or~
: .;;Mode .! :;; Kev MO.·IIJ~~et
;>

;,," , ';

::ANS! :Mode:and,Corsor'
~eyMOdel~

:ESC.L A,'; ,.

EserB'
~c:fC
~SC[I)

Auxiliary Keypad - The keys on the auxiliary keypad normally transmit the codes
for the numerals. decimal point. minus sign. and comma. In addition. the key
labeled ENTER transmits the same code as the RETU RN key. The host cannot tell
if these keys were typed on the auxiliary keypad as opposed to the corresponding
keys on the main keyboard. Therefore. software which requires considerable numeric data entry need not be rewritten to use the keypad.
However. if software must be able to distinguish between pressing a key on the
auxiliary keypad and pressing the corresponding key on the main keyboard. the
host can give the terminal a command to place it in keypad application mode. In
keypad application mode all keys on the auxiliary keypad are defined to give control sequences which may be used by the host as user-defined functions.
The codes sent by the auxiliary keypad for the four combinations of the
VT52/ANSI mode and keypad numeric/application mode are shown in Tables 3-7
and 3-8. None of the keys are affected by pressing the SHIFT. CAPS LOCK.or
CTRL keys.

Table 3-7
VT52 Mode
Auxiliary Keypad Codes
Key

Keypad
Application
Mode

1
2

3
4

ESC?p
ESC?q
ESC?r
ESC?s
ESC?t

- (dash)
• (comma)
. (period)
ENTER

- (dash)
ESC?m
• (comma)
ESC? I·
. (period)
ESC?"
Same as RETU RN
key
ESC?M

ESC?u
ESC?\'
ESC?,w
ESC?x
ESC?y

PF1
PF2
PF3
PF4

ESCP
ESCQ
ESCR
ESCS

5
6
7
8

Key

*The Jast chat:acterof this escape sequence is a lowercase L (154 8 ).

Keypad
Numeric
Mode

Keypad
Application
Mode

Keypad
Numeric
Mode

ESCP
ESCQ
ESCR
ESCS

PROGRAMMER INFORMATION

Keypad

Appli~ation

Keypad
'Application' ,

Mod~",

MOdEr "

Keypad

.~(~~!~~)

':,(~y~ibd);, ,', .,,(per i9d),", ',"

Table 3-8
ANSI Mode
Auxiliary Keypad Codes

:i~g~~',· '
",

",ESC'OIl ,"

, ENTeflj:;;~am~ as~ETfUPlf\l:; . : i' :,
:kev • ,'., <:,;'):;'::;";;'ESC()!M'~
fv: l

"~ <, f

I:,'" ~
t

0';"0;

· .' .Esc~ip .; i';:; ,;.~.;::ES¢'OJ>H.;.

ESCPQ··'? Esc;;O:9;";

'~C~R .",·,ESt'OR,L
Ji;S~'O S~.'

ESC;;:Q:S

NOTE
In ANSI mode, if the codes
are echoed back to the
VT100, or if the terminal is in
local mode, the last character
of the sequence will be displayed on the screen; e.g.,
PF 1 will display a "P."

Special Graphics Characters
If the Special Graphics set is selected, the graphics for ASCII codes 137 8 through
176 8 will be replaced according to Table 3-9. (See the SCS control sequence.)
Graphic

Graphic
with

Graphic with

with

Graphic with

Octal

USor

"Special Graphics"

Octal

USor

"Special Graphics"

Code

UK Set

Set

Code

UK Set

Set

157

Horizontal line - Scan 1

160

Horizontal line - Scan 3

161

Horizontal line - Scan 5

Horizontal line - Scan 7

Horizontal line - Scan 9

I-

Left "I"

137

Blank

140

141

• Checkerboard
Diamond

...

(error indicator)

162

142

Horizontal tab
FF Form Feed

163

143
144

~ Carriage return

164

145

L Line feed
F

165

-I

Right "I"

166

Bottom "I"

Top'T"

146

Degree symbol

147

± Plus/minus

167

150

New line

170

l Vertical tab

171

Less than or equal to

172

'.,.

Greater than or equal to

{

,... Upper-left corner

173
174,

Lower-left corner

175

151
152

153

154

...I

LoweHight corner

, Upper-right corner

155

156

+ Crossing lines

176

I
J

Vertical Bar

Pi
Not equal to

""£ ,U K pound sign
Centered dot

NOTE '1:, Codes 1528 -156 8, 1,61,8, and 1648.,...1708 are used to draw rectangular grids;'eachpiece
of this line drawing set is contiguous with others so that the lines ,formed are unbroken:
NOTE 2: Codes 157 8 -163 8 give better vertical resolution than dashes ~nd underlines When drawc
ing graphs; using these segments 120 .x 132 'resolutiorimaybe obtained in 132 collunn
mode with the Advanced Video Qption instalied.

Table 3-9
Special Graphics Characters

PROGRAMMER INFORMATION

COMMUNICATIONS
PROTOCOLS

Full Duplex
The terminal can operate at transmission speeds up to 19,200 baud. However, the
terminal may not be able to keep up with incoming data. The terminal stores
incoming characters in a 64-character buffer and processes them on a first-in/firstout basis. When the content of the buffer reaches 32 characters, the terminal wi!!
transmit 0238 (XOFF or DC3). On this signal the host should suspend its transmission to the terminal. Eventually, if the host stops transmitting, the terminal will
deplete the buffer. When 16 characters remain in the buffer the terminal will
transmit 0218 (XON or DC1) to signal the host that it may resume transmission.
If the host fails to respond to an XOFF from the terminal in a timely manner, the
buffer will continue to fill. When the 64-character capacity of the buffer is exceeded, a condition occurs called "buffer overflow." To determine if the buffer will
overflow use the following formulas:
No. of characters to overflow =
Time to respond to XOFF

32 - [3 X (receiver speedltransmit speed) 1
No. of characters to overflow X
(bits per character
parity bit
2)/receiver speed

Examp!e 1:
The VT100 is transmitting 8-bit characters with no parity at 1200 baud and receiving at 1200 baud. The terminal has just sent an XOFF which the host must
respond to within 0.2416 second to avoid a buffer overflow.
No. of characters to overflow =
Time to respond to XOFF

32 - [ 3 X (1200/1200) J = 29 characters
29 X (8+0+2)/1200 = 0.2416 second

Example 2:
The VT100 is transmitting 7 -bit characters with parity at 300 baud and receiving
at 1200 baud. The terminal has just sent an XOFF which the host must respond to
within 0.1666 second to avoid a buffer overflow.
No. of characters to overflow =
Time to respond to XOFF

32 - [ 3 X (1200/300) 1 = 20 characters
20 X (7

+ 1 +2)11200 = 0.1666 second

If the buffer overflows, the VT100 will begin to discard incoming characters and
the error character will be displayed.
Software which does not support receipt of the XOFF/XON signals from the terminal can still use the VT100 provided the software never sends the ESC code to the
terminal. the baud rate is limited to 4800 or less, and the software does not use
smooth scrolling or split screen features.
Alternatively, if XOFF/XON cannot be used, fill characters may be used after characters or character strings are sent to the VT100. A reference chart of fill characters required for these functions is included in Appendix C.

Two of the terminal functions, Reset and Self-Test. reinitialize the terminal and
erase the buffer. This means that if characters are received subsequent to the

PROGRAMMER INFORMATION

commands to perform these two functions and the characters are placed in the
buffer, the character would be destroyed without being processed.
To compensate for this, the host may act in one of two ways:
1.

Immediately after sending the terminal the commands to perform either
the Reset or Self-Test functions, the host may act as if it had received
XOFF from the terminal. thus sending no more characters until it receives XON. The terminal will transmit XON only after it completes the
specified operation and the XOFF/XON feature is enabled.

When the first method cannot be implemented, a delay of no less than
10 seconds may be used to allow the terminal time to complete the
invoked function. This method, however, does not guarantee against
the loss of data when an invoked function has detected an error; and
while this delay is currently adequate, future options may require a
change in the time delay.

The XOFF/XON synchronization scheme has an advantage over requiring the host
to insert delays or filler characters in its data stream. Requiring a minimum of
software support, XON/XOFF ensures that every character or command sent to
the VT100 will be processed in correct order. It frees interface programs from all
timing considerations and results in more reliable operation.
In addition to the buffer-filling condition, there are two other means of transmitting
XOFF and XON; the NO SCROLL key, and Control S/Control Q. If the XON/XOFF
feature is enabled, the VT100 will coordinate these three sources of XOFF and
XON so that the desired effect occurs. For example, if the buffer-filling condition
has caused an XOFF to be sent, and then the operator types the NO SCROLL key,
a second XOFF is not sent. Instead of sending an XON when the buffer empties,
the VT100 waits until the operator types the NO SCROLL key again before sending XON.
Also, entering SET-UP mode causes the VT100 to temporarily stop taking characters from the buffer. An XOFF will be sent if the buffer becomes nearly full.
Use of Control S and Control Q will also be synchronized with the NO SCROLL
key.
If the XON/XOFF feature is disabled, the buffer-filling condition will not send an
XOFF, the NO SCROLL key is disabled, and Control S and Control Q will be
transmitted as typed.
The VT100 also recognizes received XOFF and XON. Receipt of XOFF will inhibit
the VT100 from transmitting any codes except XOFF and XON. From three to
seven keystrokes on the keyboard will be stored in a keyboard buffer (some keys
transmit two or three codes, e.g., cursor controls). If the keyboard buffer overflows,
keyclicks will stop and the KBD LOCKED LED will come on. Transmission resumes
upon receipt of XON.
If the user transmits an XOFF to the host (by Control S or NO SCROLL), the host
should not echo any further type-in until the user types XON. This places the
burden of not overloading the host's output buffer on the user.
Entering and exiting SET -U P clears the keyboard locked condition.

PROGRAMMER INFORMATION

TERMINAL
CONTROL
COMMANDS

The VT100 has many control commands which cause it to take action other than
displaying a character on the screen. In this way, the host can command the
terminal to move the cursor, change modes, ring the bell. etc. The following paragraphs discuss the terminal control commands.

Control Characters

Control characters have values of OOOS - 037s, and 177s. The control characters
recognized by the VT100 are shown in Table 3-10. All other control codes cause
no action to be taken.
Control characters (codes as to 37 s inclusive) are specifically excluded from the
control sequence syntax, but may be embedded within a control sequence. Embedded control characters are executed as soon as they are encountered by the
VT100. The processing of the control sequence then continues with the next character received. The exceptions are: If the character ESC occurs, the current control sequence is aborted, and a new one commences beginning with the ESC just
received. If the character CAN (30S) or the character SU B (32S) occurs, the current control sequence is aborted. The ability to embed control characters allows
the synchiOnization characters XON and XOFF to be interpreted properly without
affecting the control sequence.

Table 3-10
Control Characters

Ignored

on illput (not stof,oo in I~~ufooffer;,seefunduplex pro-

,:~t~).""'"

ENQ

,,'

;"",;.,,_~,~. ;005 ~..;~;,,,:T r<lnsm!t,ans~e~,ac.k.~m,essa~:~~

Move cursor to left margin on the current line.
tn~ok~ G 1 charapter s~t,as de,signated by SCS control sequence.

Select G,Ocharacter set, as selected by "ESC(

SI.

sequence.

,'''',L4.Causes terminal to resume transmission.

"XON'
·XOFF,

:023

"Causes terminal to stop transmitting all codes except XOFF and,
XON,

CAN

030

, If sent during a control sequence, the sequence is immediately ter."minated and not executed. It also causes the error character to be
,displayed.

SUB

032

Interpreted as CAN.

ESC

033

'Introduces a control sequence.

DEL

1'"1'"1
II

Ignored on input (not st,ored in input buffer),

PROGRAMMER INFORMATION

The VT100 is an upward and downward software compatible terminal; that is,
previous DIGITAL video terminals have DIGITAL private standards for control sequences. The American National Standards Institute (ANSI) has since standardized escape and control sequences in terminals in documents X3.41-1974 and
X3.64-1977.
The VT100 is compatible with both the previous DIGITAL standard and ANSI
standards. Customers may use existing DIGITAL software designed around the
VT52 or new VT100 software. The VT100 has a "VT52 compatible" mode in
which the VT100 responds to control sequences like a VT52. In this mode, most of
the new VT100 features cannot be used.

Control Sequences

NOTE
The ANSI standards allow the
manufacturer flexibility in implementing each function.
This manual describes how
the VT100 will respond to the
implemented ANSI central
function.

Throughout this section of the manual. references will be made to "VT52 mode" or
"ANSI mode." These two terms are used to indicate the VT100's software com
patibility. All new software should be designed around the VT100 "ANSI mode."
Future DIGITAL video terminals will not necessarily be committed to VT52 compatibility.

NOTE
ANSI standards may be obtained by writing:
Sales Department
American National Standards
Institute
1430 Broadway
New York, New York 10018

Definitions
The following listing defines the basic elements of the ANSI mode control sequences. A more complete listing appears in Appendix A.

Valid ANSI
Mode Control
Sequences

• Control Sequence Introducer (CSI) - An escape sequence that provides
supplementary controls and is itself a prefix affecting the interpretation of
a limited number of contiguous characters. In the VT100 the CSI is ESC[.
• Parameter - (1) A string of zero or more decimal characters which represent a single value. Leading zeros are ignored. The decimal characters
have a range of 0 (608) to 9 (71 8 ), (2) The value so represented.
• Numeric Parameter - A parameter that represents a number, designated
by Pn.
• Selective Parameter - A parameter that selects a subfunction from a
specified list of subfunctions, designated by Ps. In general. a control sequence with more than one selective parameter causes the same effect as
several control sequences, each with one selective parameter, e.g., CSI
Psa; Psb; Psc F is identical to CSI Psa F CSI Psb F CSI Psc F.
• Parameter String - A string of parameters separated by a semicolon (73a).
• Default - A function-dependent value that is assumed when no explicit
value, or a value of 0, is specified.
• Final Character - A character whose bit combination terminates an escape
or control sequence.

PROGRAMMER INFORMATION

Examples:
1. Control sequence for double-width line (DECDWL)

Octal Representation
of Sequence

Sequence
);'~r

.11

L>J'-'

Escape
Character

ESC # 6

)

Final
Character

033

043

Escape
Character

066

Final
Character

Intermediate
Character

2. Control sequence to turn off all character attributes, and then turn on underscore
and blink attributes (SGR). ESC [ 0 : 4 : 5 m
Octal Representation
of Sequence

Sequence
delimiter

~ delir
ESC[

delimiter
iter

o ; 4 ;

5 m

~
t
033 133 060 073 064 073 065
delimiter

Selective
Parameters

Parameter string

CSI

Final
character

CSI

155

Final
character

Alternative sequences which will accomplish the same thing:
Sequence

Octal Representation
of Sequence

a. ESC [; 4: m

033 133 073 064 073 065 155

b. ESC [m

033 133 155
033 133 064 155
033 133 065 155

ESC [4m
ESC [5m
c.

ESC [0; 04; 005 m 033 133 060 073 060064 073 060 060065 155

PROGRAMMER INFORMATION

Control Sequences
All of the following escape and control sequences are transm itted from the host
computer to the VT100 unless otherwise noted. All of the control sequences are a
subset of those specified in ANSI X 3.64 1977 and ANSI X-3.41 1974.

Cursor Position Report -

CPR

VT100 to Host

ESC [Pn; Pn R

default value: 1

The CPR sequence reports the active position by means of the parameters.' This
sequence has two parameter values, the first specifying the line and the second
specifying the column. The default condition with no parameters present, or parameters of 0, is equivalent to a cursor at home position.
The numbering of lines depends on the state of the Origin Mode (DECOM).
This control sequence is solicited by a device status report (DSR) sent from the
host.

Cursor Backward -

CUB

Host to VT100 and VT100 to Host

ESC [Pn D

default value: 1

The CU B sequence moves the active position to the left. The distance moved is
determined by the parameter. If the parameter value is zero or one, the active
position is moved one position to the left. If the parameter value is n, the active
position is moved n positions to the left. If an attempt is made to move the cursor
to the left of the left margin, the cursor stops at the left margin. Editor Function

Cursor Down -

CUD

Host to VT100 and VT100 to Host

ESC [Pn B

default value: 1

The CUD sequence moves the active position downward without altering the column position. The number of lines moved is determined by the parameter. If the
parameter value is zero or one, the active position is moved one line downward. If
the parameter value is n, the active position is moved n lines downward. If an
attempt is made to move the cursor below the bottom margin, the cursor stops at
the bottom margin. Editor Function

Cursor Forward -

ESC [Pn C

CUF

Host to VT100 and VT100 to Host
default value: 1

The CU F sequence moves the active position to the right. The distance moved is
determined by the parameter. A parameter value of zero or one moves the active
position one position to the right. A parameter value of n moves the active position
n positions to the right. If an attempt is made to move the cursor to the right of the
right margin, the cursor stops at the right margin. Editor Function

CUP

Cursor Position

ESC [Pn; PnH

default value: 1

The CUP sequence moves the active position to the position specified by the
parameters. This sequence has two parameter values, the first specifying the line

PROGRAMMER INFORMATION

position and the second specifying the column position. A parameter value of zero
or one for the first or second parameter moves the active position to the first line or
column in the display. respectively. The default condition with no parameters present is equivalent to a cursor to home action. In the VT100. this control behaves
identica!ly with its format effector counterpart. HVP. Editor Function
The numbering of lines depends on the state of the Origin Mode (DECOM).

CU U

Cursor Up -

Host to Vii 00 and Vii 00 to Host

ESC [Po A

default value: 1

Moves the active position upward without altering the column position. The number of lines moved is determined by the parameter. A parameter value of zero or
one moves the active position one line upward. A parameter value of n moves the
active position n lines upward. If an attempt is made to move the cursor above the
top margin, the cursor stops at the top margin. Editor Function

Device Attributes

ESC [Po c
1.

The host requests the VT100 to send a device attributes (DA) control
sequence to identify itself by sending the DA control sequence with
either no parameter or a parameter of O.

Response to the request described above (VT100 to host) is generated
by the VT100 as a DA control sequence with the numeric parameters
as follows:

Option Present
No options
Processor option (STP)
Advanced video option (AVO)
AVO and STP
Graphics option (GPO)
GPO and STP
GPO and AVO
GPO, STP. and AVO

DECALN

default value: 0

Sequence Sent

ESC [?l;Oc
ESC [?l;lc
ESC [?1;2c
ESC [?1;3c
ESC [?1;4c
ESC [?1;5c
ESC [?1;6c
ESC [?1;7c

Screen Alignment Display (DEC Private)

ESC # 8
This command fills the entire screen area with uppercase Es for screen focus and
alignment. This command is used by DEC manufacturing and Field Service personnel.

DECANM

ANSI/VT52 Mode (DEC Private)
This is a private parameter applicable to set mode (SM) and reset mode (RM)
control sequences. The reset state causes only VT52 compatible escape sequences to be interpreted and executed. The set state causes only ANSI "compatible" escape and control sequences to be interpreted and executed.

PROGRAMMER INFORMATION

Auto Repeat Mode (DEC Private)

DECARM

This is a private parameter applicable to set mode (SM) and reset mode (RM)
control sequences. The reset state causes no keyboard keys to auto-repeat. The
set state causes certain keyboard keys to auto-repeat.

Autowrap Mode (DEC Private)

DECAWM

This is a private parameter applicable to set mode (SM) and reset mode (RM)
control sequences. The reset state causes any displayable characters received
when the cursor is at the right margin to replace any previous characters there. The
set state causes these characters to advance to the start of the next line. doing a
scroll up if required and permitted.

Cursor Keys Mode (DEC Private)

DECCKM

This is a private parameter applicable to set mode (SM) and reset mode (RM)
control sequences. This mode is only effective when the terminal is in keypad
application mode (see DECKPAM) and the ANSI/VT52 mode (DECANM) is set
(see DECANM). Under these conditions. if the cursor key mode is reset. the four
cursor function keys will send ANSI cursor control commands. If cursor key mode
is set. the four cursor function keys will send application functions.

Column Mode (DEC Private)

DECCOLM

This is a private parameter applicable to set mode (SM) and reset mode (RM)
control sequences. The reset state causes a maximum of 80 columns on the
screen. The set state causes a maximum of 132 columns on the screen.

Double Height Line (DEC Private)

DECDHL

Top Half: ESC # 3
Bottom Half: ESC # 4
These sequences cause the line containing the active position to become the top
or bottom half of a double-height double-width line. The sequences must be used
in pairs on adjacent lines and the same character output must be sent to both lines
to form full double-height characters. If the line was single-width single-height. all
characters to the right of the center of the screen are lost. The cursor remains over
the same character position unless it would be to the right of the right margin. in
which case it is moved to the right margin.

The use of double-width characters reduces the number of
characters per line by half.

Double-Width Line (DEC Private)

DECDWL

NOTE

ESC # 6
This causes the line that contains the active position to become double-width
singie-height. If the line was single-width single-height. all characters to the right
of the screen are lost. The cursor remains over the same character position unless
it would be to the right of the right margin: in which case. it is moved to the right
margin.

NOTE
The use of double-width characters reduces the number of
characters per line by half

PROGRAMMER INFORMATION

DECID

Identify Terminal (DEC Private)

ESC Z
This sequence causes the same response as the ANSI device attributes (OA). This
sequence will not be supported in future DEC terminals. therefore. DA shouid be
used by any new software.
DECINLM

Interlace Mode (DEC Private)
This is a private parameter applicable to set mode (SM) and reset mode (RM)
control sequences. The reset state (non-interlace) causes the video processor to
display 240 scan lines per frame. The set state (interlace) causes the video processor to display 480 scan lines per frame. There is no increase in character resolution.

DECKPAM

Keypad Application Mode (DEC Private)

ESC ::::
The auxiliary keypad keys will transmit control sequences as defined in Tables 3-7
and 3-8.
DECKPNM

Keypad Numeric Mode (DEC Private)

ESC>
The auxiliary keypad keys will send ASCII codes corresponding to the characters
engraved on the keys.
DECLL

Load LEDS (DEC Private)

ESC [Ps q

default value: 0

Load the four programmable LEOs on the keyboard according to the parameter(s).
Parameter

o
1
2

3
4

Parameter Meaning
Clear LEOs L 1 through L4
Light L 1
Light L2
Light L3
Light L4

LED numbers are indicated on the keyboard.
DECOM

Origin Mode (DEC Private)
This is a private parameter applicable to set mode (SM) and reset mode (RM)
control sequences. The reset state causes the origin to be at the upper-left character position on the screen. Line and column numbers are. therefore, independent of
current margin settings. The cursor may be positioned outside the margins with a
cursor position (CUP) or horizontal and vertical position (HVP) control.
The set state causes the origin to be at the upper-left character position within the
margins. Line and column numbers are therefore relative to the current margin
settings. The cursor is not allowed to be positioned outside the margins.

PROGRAMMER INFORMATION

The cursor is moved to the new home position when this mode is set or reset.
Lines and columns are numbered consecutively, with the origin being line 1, column 1.

Restore Cursor (DEC Private)

DECRC

ESC 8
This sequence causes the previously saved cursor position, graphic rendition, and
character set to be restored.

Report Terminal Parameters

DECREPTPARM

ESC [ <sol>; <par>; <nbits>; <xspeed>;
<rspeed>; <clkmul>; <flags>x
These sequence parameters are explained below in the DECREOTPARM sequence.

Request Terminal Parameters

ESC [ <sol> x
The sequence DECREPTPARM is sent by the terminal controller to notify the host
of the status of selected terminal parameters. The status sequence may be sent
when requested by the host or at the terminal's discretion. DECREPTPARM is sent
upon receipt of a DECREOTPARM. On power-up or reset. the VT100 is inhibited
from sending unsolicited reports.
The meanings of the sequence parameters are:

Parameter

Value

Meaning

<sol>

o or none

This message is a request (DECREOTPARM) and
the terminal will be allowed to send unsolicited reports. (Unsolicited reports are sent when the terminal exits the SET-UP mode.)
This message is a request; from now on the terminal
may only report in response to a request.

This message is a report (DECREPTPARM).

This message is a report and the terminal is only
reporting on request.
No parity set

<par>

Parity is set and odd

Parity is set and even
8 bits per character

<nbits>

7 bits per character

DECREQTPARM

PROGRAMMER INFORMATION

Parameter

Value

r 08
I
I

I
I
I

16
24
32
40
48
56
64
72
80
88
96
104
112
120

DECSe

50
75
II
110
I
I
134.5
I
150
200
I
300
I
600
Bits per second
1200
1800
2000
2400
3600
4800
9600
19200 j

The bit rate multiplier is 16.

Meaning

0-15

This value communicates the four switch values in
block 5 of SET UP B, which are only visible to the
user when an STP option is installed. These bits may
be assigned for an STP device. The four bits are a
decimal-encoded binary number.

Save Cursor (DEC Private)

ESC i
This sequence causes the cursor position, graphic rendition, and character set to
be saved. (See D ECRC.)
DECSCLM

Scrolling Mode (DEC Private)
This is a private parameter applicable to set mode (SM) and reset mode (RM)
control sequences. The reset state causes scrolls to "jump" instantaneously. The
set state causes scrolls to be "smooth" at a maximum rate of six lines per second.

DECSCNM

Screen Mode (DEC Private)
This is a private parameter applicable to set mode (SM) and reset mode (RM)
control sequences. The reset state causes the screen to be black with white characters. The set state causes the screen to be white with black characters.

DECSTBM

Set Top and Bottom Margins (DEC Private)

ESC [Po; Po r

default values: see below

This sequence sets the top and bottom margins to define the scrolling region. The
first parameter is the line number of the first line in the scrolling region; the second
parameter is the line number of the bottom line in the scrolling region. Default is
the entire screen (no margins). The minimum size of the scrolling region allowed is
two lines, i.e., the top margin must be less than the bottom margin. The cursor is
placed in the home position (see Origin Mode DECOM).

PROGRAMMER INFORMATION

Single-width Line (DEC Private)

DECSWL

ESC # 5
This causes the line which contains the active position to become single-width
single-height. The cursor remains on the same character position. This is the
default condition for all new lines on the screen.

DECTST

I nvoke Confidence Test

ESC [ 2 ; Ps y
Ps is the parameter indicating the test to be done. Ps is computed by taking the
weight indicated for each desired test and adding them together. If Ps is 0, no test
is performed but the VT100 is reset.

Test

Weight

Power up self-test (ROM check
sum, RAM, NVR keyboard
and AVO if installed)
Data Loop Back

2 (loop back connector required)

EIA modem control test

4 (loop back connector required)

Repeat Selected Test(s)
indefinitely (until failure or
power off)

Device Status Report

ESC [Ps n

DSR
default value: 0

Requests and reports the general status of the VT100 according to the following
parameter(s).

Parameter

Parameter Meaning

Response from VT100 - Ready, No malfunctions
detected (default)

Response from VT100 - Malfunction - retry

Command from host - Please report status (using a
DSR control sequence)

Command from host - Please report active position
(using a CPR control sequence)

DSR with a parameter value of 0 or 3 is always sent as a response to a requesting
DSR with a parameter value of 5.

PROGRAMMER INFORMATION

Erase I n Display
default value: a

ESC [PsJ

This sequence erases some or all of the characters in the display according to the
parameter. Any complete line erased by this sequence wil; return that line to singie
width mode. Editor Function
Parameter

Parameter Meaning

Erase from the active position to the end of the
screen, inclusive (default)
Erase from start of the screen to the active position,
inclusive

Erase all of the display - all lines are erased,
changed to single-width, and the cursor does not
move.

Erase In Line
default value: a

ESC [Ps K

Erases some or all characters in the active line according to the parameter. Editor
Function
Parameter

Parameter Meaning

Erase from the active position to the end of the line,
inclusive (default)
Erase from the start of the screen to the active position, inclusive

HTS

Erase all of the line, inclusive

Horizontal Tabulation Set

ESC H
Set one horizontal stop at the active position. Format Effector
HVP

Horizontal and Vertical Position

ESC [Po; Po f

default value: 1

Moves the active position to the position specified by the parameters. This sequence has two parameter values, the first specifying the line position and the
second specifying the column. A parameter value of either zero or one causes the
active position to move to the first line or column in the display, respectively. The
default condition with no parameters present moves the active position to the

PROGRAMMER INFORMATION 53

home position. In the VT100, this control behaves identically with its editor function counterpart, CUP. The numbering of lines and columns depends on the reset
or set state of the origin mode (DECOM). Format Effector

Index

INC

ESC D
This sequence causes the active position to move downward one line without
changing the column position. If the active position is at the bottom margin, a
scroll up is performed. Format Effector

Line Feed/New Line Mode

LNM

This is a parameter applicable to set mode (SM) and reset mode (RM) control sequences. The reset state causes the interpretation of the line feed (LF), defined in
AN SI Standard X3.4-1977, to imply only vertical movement of the active position
and causes the RETU RN key (CR) to send the single code CR. The set state causes
the LF to imply movement to the first position of the following line and causes the
RETURN key to send the two codes (CR, LF). This is the New Line (NL) option.
This mode does not affect the index (lND), or next line (NEL) format effectors.

Next Line

NEL

ESC E
This sequence causes the active position to move to the first position on the next
line downward. If the active position is at the bottm margin, a scroll up is performed. Format Effector

Reverse Index

ESC M
Move the active position to the same horizontal position on the preceding line. If
the active position is at the top margin, a scroll down is performed. Format Effector

Reset To Initial State

RIS

ESC c
Reset the VT100 to its initial state, i.e., the state it has after it is powered on. This
also causes the execution of the power-up self-test and signal INIT H to be asserted briefly.

Reset Mode

ESC [ Ps ;Ps ; ... ; Ps I

default value:none

Resets one or more VT100 modes as specified by each selective parameter in the
parameter string. Each mode to be reset is specified by a separate parameter. [See
Set Mode (SM) control sequence.] (See Modes following this section.)

PROGRAMMER INFORMATION

SCS

Select Character Set
The appropriate GO and G 1 character sets are designated from one of the five
possible character sets. The GO and G 1 sets are invoked by the codes SI and SO
(shift in and shift out) respectively.

NOTE
Additional information concerning the SCS escape sequence may be obtained in
ANSI standard X3.41-1974.

SGR

GO Sets
Sequence

G1 Sets
Sequence

ESC( A
ESC( 8
ESC(O
ESC ( 1

ESC)A
ESC)8
ESC)O
ESC) 1

United Kingdom Set
ASCII Set
Special Graphics
Alternate Character ROM
Standard Character Set

ESC(2

ESC)2

Alternate Character ROM
Special Graphics

Meaning

The United Kingdom and ASCII sets conform to the "'SO international register of
character sets to be used with escape sequences." The other sets are private
character sets. Special graphics means that the graphic characters for the codes
1378 to 1768 are replaced with other characters. The specified character set will
be used until another SCS is received.
Select Graphic Rendition

ESC [ Ps; ... ; Ps m

default value: 0

Invoke the graphic rendition specified by the parameter(s). All following characters
transmitted to the VT100 are rendered according to the parameter(s) until the next
occurrence of SGR. Format Effector
Parameter

Parameter Meaning

Attributes off
Bold or increased intensity
Underscore
Blink
Negative (reverse) image

1
4
5
7

All other parameter values are ignored.
Without the Advanced Video Option, only one type of character attribute is possible as determined by the cursor selection; in that case specifying either the
underscore or the reverse attribute will activate the currently selected attribute.
(See cursor selection in Chapter 1.)

Set Mode

ESC Ps; ... ; Ps h

default value: none

Causes one or more modes to be set within the VT100 as specified by each
selective parameter in the parameter string. Each mode to be set is specified by a
separate parameter. A mode is considered set until it is reset by a reset mode (RM)
control sequence.

PROGRAMMER INFORMATION

Tabulation Clear

TBC

ESC [Ps g

default value: 0

Parameter

Parameter Meaning

Clear the horizontal tab stop at the active position
(the default case).

Clear all horizontal tab stops.

Any other parameter values are ignored. Format Effector

The following is a list of VT100 modes which may be changed with set mode (SM)
and reset mode (RM) controls.
ANSI Specified Modes
Parameter

Mode
Mnemonic

LNM

Mode Function
Error (ignored)
Line feed new line mode

DEC Private Modes
If the first character in the parameter string is ? (778). the parameters are interpreted as DEC private parameters according to the following:

Parameter

Mode
Mnemonic

Mode Function

0
1
2
3
4

DECCKM
DECANM
DECCOLM
DECSCLM

Error (ignored)
Cursor key
ANSI/VT52
Column
Scrolling

DECSCNM
DECOM
DECAWM
DECARM
DECINLM

Screen
Origin
Auto wrap
Auto repeating
Interlace

5
6
7

8
9

Any other parameter values are ignored.
The following modes, which are specified in the ANSI X3.64-1977 standard, may
be considered to be permanently set, permanently reset. or not applicable, as
noted. Refer to that standard for further information concerning these modes.
Mode
Mnemonic
CRM
EBM
ERM
FEAM
FETM

Mode Function
Control representation
Editing boundary
Erasure
Format effector action
Format effector transfer

State
Reset
Reset
Set
Reset
Reset

MODES

PROGRAMMER INFORMATION

Mode
Mnemonic

Mode Function

State

GATM
HEM
IRM
KAM
MATM

Guarded area transfer
Horizontal editing
Insertion-replacement
Keyboard action
Multiple area transfer

NA
NA
Reset
Reset
NA

PUM
SRTM
TSM
TIM

Positioning unit
Selected area transfer
Status reporting transfer
Tabulation stop
Transfer termination

Reset
NA
Reset
Reset
NA

VEM

Vertical editing

SATM

Valid VT52
Mode Control
Sequences
Cursor Up

ESC A
Move the active position upward one position without altering the horizontal position. If an attempt is made to move the cursor above the top margin, the cursor
stops at the top margin.
Cursor Down

ESC B
Move the active position downward one position without altering the horizontal
position. If an attempt is made to move the cursor below the bottom margin, the
cursor stops at the bottom margin.
Cursor Right

ESC C
Move the active position to the right. If an attempt is made to move the cursor to
the right of the right margin, the cursor stops at the right margin.
Cursor Left

ESC D
Move the active position one position to the left. If an attempt is made to move the
cursor to the left of the left margin, the cursor stops at the left margin.

NOTE Enter Graphics Mode
The special graphics
characters in the VT100
are different from those
in the VT52.

ESC F
Causes the special graphics character set to be used.

PROGRAMMER INFORMATION

Exit Graphics Mode

ESC G
This sequence causes the standard ASCII character set to be used.
Cursor to Home

ESC H
Move the cursor to the home position.
Reverse Line Feed

ESC I
Move the active position upward one position without altering the column position. If the active position is at the top margin. a scroll down is performed.
Erase to End of Screen

ESC J
Erase all characters from the active position to the end of the screen. The active
position is not changed.
Erase to End of Line

ESC K
Erase all characters from the active position to the end of the current line. The
active position is not changed.
Direct Cursor Address

ESC Y line column
Move the cursor to the specified line and column. The line and column numbers
are sent as ASCII codes whose values are the number plus 0378 ; e.g .. 040a refers
to the first line or column. 0508 refers to the eighth line or column. etc.
Identify

ESC Z
This sequence causes the terminal to send its identifier escape sequence to the
host. This sequence is:

ESC / Z.
Enter Alternate Keypad Mode

ESC

The optional auxiliary keypad keys will send unique identifiable escape sequences
for use by applications programs.

NOTE
Information regarding
options must be obtained in ANSI mode.
using the device attributes (DA) control sequence.

PROGRAMMER INFORMATION

Exit Alternate Keypad Mode

ESC>
The optional auxiliary keypad keys send the ASCII codes for the functions or characters engraved on the key.
Enter ANSI Mode

ESC <
All subsequent escape sequences will be interpreted according to ANSI Standards
X3.64-1977 and X3.41-1974. The VT52 escape sequence designed in this section will not be recognized.
Control Sequence
Summary
ANSI Compatible
Mode

NOTE
Pn refers to a decimal parameter expressed as a string of
ASCII digits. Multiple parameters are separated by the
semicolon character (0738). If
a parameter is omitted or
specified to be 0 the default
parameter value is used. For
the cursor movement commands, the default parameter
value is 1.

The following is a summary of the VT100 control sequences.

Cursor Movement Commands
Cursor up
Cursor down
Cursor forward (right)
Cursor backward (Jeft)
Direct cursor addressing
Index
New line
Reverse index
Save cursor and attributes
Restore cursor and attributes

ESC [Po A
ESC [Po B
ESC [Po C
ESC [Po D
ESC [PI; Pc Ht or
ESC [ PI; Pc ft
ESCD
ESCE
ESCM
ESC7
ESC8

tPI = line number; Pc = column number.

Line Size (Double-Height and Double-Width) Commands
Change this line to double-height top half
Change this line to double-height bottom half
Change this line to single-width single-height
Change this line to double-width single-height

ESC#3
ESC#4
ESC#5
ESC#6

Character Attributes

ESC [ Ps;Ps;Ps; ... ;Ps m
Ps refers to a selective parameter. Multiple parameters are separated by the semicolon character (0738). The parameters are executed in order and have the following meanings:

o or None
1
4

5
7

All Attributes Off
Bold on
Underscore on
Blink on
Reverse video on

Any other parameter values are ignored.

PROGRAMMER INFORMATION

Erasing

ESC [ K or ESC [ 0 K
ESC [1 K
ESC [2 K
ESC [ J or ESC [ 0 J
ESC [ 1 J
ESC[2J

From cursor to end of line
From beginning of line to cursor
Entire line containing cursor
From cursor to end of screen
From beginning of screen to cursor
Entire screen

Programmable LE Ds

ESC [ Ps;Ps; ... Ps q
Ps are selective parameters separated by semicolons (0738) and executed in order, as follows:

o or None
1
2
3
4

All LEDs Off
L10n
L2 On
L3 On
L40n

Any other parameter values are ignored.

Character Sets (GO and G1 Designators)
The GO and G 1 character sets are designated as follows:
Character set

GO designator

G1 designator

United Kingdom (U K)
United States (USASCII)
Special graphics characters
and line drawing set
Alternate character ROM
Alternate character ROM
special graphics characters

ESC(A
ESC(B
ESC(O

ESC)A
ESC)B
ESC)O

ESC( 1
ESC(2

ESC) 1
ESC)2

Scrolling Region

ESC [ Pt ; Pb r
Pt is the number of the top line of the scrolling region; Pb is the number of the
bottom line of the scrolling region and must be greater than Pt.

Tab Stops:
Set tab at current column
Clear tab at current column
Clear all tabs

ESCH
ESC [ g or ESC [ 0 g
ESC[3g

PROGRAMMER INFORMATION

Modes
To Set
Sequence

To Reset
Mode
Sequence

Smooth

ESC [20h
ESC [?lh
tV/A
ESC [?3h
ESC [?4h

Line feed ESC [20/*
Cursor
ESC [?11*
VT52
ESC [?21*
ESC [?31*
80 Coi
ESC [?41*
Jump

Reverse
Relative
On
On
On
Application

ESC [?Sh
ESC [?6h
ESC [?7h
ESC [?8h
ESC [?9h
ESC

Normal
Absolute
Off
Off
Off
Numeric

Mode Name

Mode

Line feed/new line
Cursor key mode
AN SI/VT52 mode
Column mode
Scrolling mode

New line
Application
ANSi

Screen mode
Origin mode
Wraparound
Auto repeat
Interlace
Keypad mode

1,)"1 1"'_1

I,;)" \"UI

ESC [?Sl*
ESC [?61*
ESC [?71*
ESC [?81*
ESC [?91*
ESC>

* The last character of the sequence is a lowercase L (154 8 ),

Reports
Cursor Position Report
Invoked by
Response is

ESC[6n
ESC [ PI ; Pc R t

+Pl = line number: Pc = column number.

Status Report
Invoked by
Response is

ESC[Sn
ESC [0 n
ESC[3n

(terminal ok)
(terminal not ok)

What Are You
Invoked by

ESC [c

Response is

ESC [0 c
ESC [? I; Ps c

Ps is the "option present" parameter with the foiiowing meaning:
Ps

Meaning

a
1
2
3

Base VT 100, no options
Processor option (STP)
Advanced video option (AVO)
AVO and STP

4
5
6
7

Graphics processor option (GPO)
GPO and STP
GPO and AVO
GPO, STP, and AVO

Alternately invoked by ESC Z (not recommended). Response is the same.

PROGRAMMER INFORMATION

Reset
Reset causes the power-up reset routine to be executed.

ESC c
Confidence Tests
Fill Screen with "Es"
Invoke Test(s)

ESC#8
ESC [2; Ps y

Ps is the parameter indicating the test to be done and is a decimal number computed by taking the "weight" indicated for each desired test and adding them
together.

Test

Weight

Power-up self test
(ROM checksum. RAM. NVR.
keyboard and AVO if installed)

Data Loop Back

2 (loop back connector required)

EIA modem control test

4 (loop back connector required)

Repeat selected test(s) indefinitely
(until failure or power off)

The following is a summary of the VT100 control sequences.
Cursor Up
Cursor Down
Cursor Right
Cursor Left
Select Special Graphics
character set

ESCA
ESCB
ESCC
ESCD

Select ASCII character set
Cursor to home
Reverse line feed
Erase to end of screen
Erase to end of line

ESCG
ESCH
ESCI
ESCJ
ESCK

Direct cursor address
Identify
Enter alternate keypad mode
Exit alternate keypad mode
Enter AN SI mode

ESC Ylc
ESCZ
ESC =
ESC>
ESC<

NOTE 1:

NOTE 2:

ESCF

(see note 1)
(see note 2)

Line and column numbers for direct cursor address are single character
codes whose values are the desired number plus 37 8 . Line and column
numbers start at 1.
Response to ESC Z is ESC / Z

VT52 Compatible
Mode

CHAPTER 4
VT100 OPTIONS
The VT100 has available options which are designed to enhance the basic terminal
and allow its use in a wide range of applications. The options currently available
are:
VT1XX-AA
VT1XX-AB

20 rnA Current Loop Option
Advanced Video Option

In the future. additional options will be available which will further enhance the
basic VT100. Contact the nearest DIGITAL Sales Office for further information and
how to order the options.
ADVANCED VIDEO OPTION - VT1XX-AB
The Advanced Video Option enhances the basic VT100 by adding the following
features:
• 10 additional lines of 132 column display - this capability is added to the
VT100 by providing additional display memory. The screen can now displaya total of 24 lines in either 80- or 132-column format.
• Additional character attributes - the VT100 is now capable of highlighting
any character(s) on the screen in any of the following ways:
Bold
Blink
Underline
Reverse
Any combination of the above
• Capability of an additional character generator ROM - this capability is
added to the VT100 by providing the memory required to access a second
character generator ROM.

OPTIONS

Advanced Video Option Installation
Use the following procedure to install the Advanced Video Option.
1. Remove power from the terminal by disconnecting the ac plug.
2. Unplug the keyboard (Figure 4-1).
3. Unplug any connectors from the composite video input/output jacks.
4. Disconnect the communications cable.
5. With a blade-type screwdriver loosen the four captive screws holding the
access cover.
6. If the 20 mA Current Loop Option is installed, gently pull the access
cover away from the terminal about 2 inches; then reach in and disconnect J5 from the terminal controller board.
7. Remove the access cover.
8. Remove any graphic or STP cables.
9. Remove the terminal controller board by gently but firmly pulling the
board straight out. The terminal controller board is located in the leftmost
slot in the card cage (viewed from the rear).
10. Place the terminal controller board on a flat surface with the component
side up (Figure 4-2).
11. Locate the four mounting holes drilled in the terminal controller board;
mount a standoff in each.
12. Grasp the advanced video board by the edges and carefully align the
connector pins with the connector on the terminal controller board.
Gently but firmly mount the advanced video board onto the terminal
controller board.
13. Reinstall the terminal controller board. The terminal controller board
must be inserted into the leftmost slot in the card cage.
14. Reinstall all cables removed.
1 5. Reinstall the access cover.
Advanced Video Option Checkout
Use the following procedure to check out the operation of the Advanced Video
Option.
1. Turn the terminal power on and verify that no error 'vvas detected during
the power up self-test.
2. Press the SET-UP key. The words "SET-UP AU should blink in boldface,
the words "TO EXIT PRESS SET-UP" should be underlined, and the ruler
should contain alternating normal and reverse video fields.
'3. Place the terminal in the 132-column mode and then in the LOCAL
mode.
4. Exit SET-UP and type the following sequence:

ESC < ESC # 8
The screen should now display 24 lines X 132 columns.

OPTIONS

ACCESS
COVER

EIA
COMMUNICATIONS
CONNECTOR
EXTERNAL VIDEO
INPUT CONNECTOR
EXTERNAL VIDEO
OUTPUT CONNECTOR
MAIN FUSE
POWER SWITCH

NUMBER LABEL

KEYBOARD
CONNECTOR

~ OPTIONAL 20mA
COMMUNICATION
CONNECTOR

POWER
SELECTOR
SWITCH

MA-1987

Figure 4-1
VT100 Rear View

STANDOFF
COMPONENT SIDE
OF ADVANCED
VIDEO BOARD

TERMINAL
CONTROLLER

J2 GRAPHICS
CONNECTOR
J520mA
CURRENT LOOP
CONNECTOR
J3 STP
CONNECTOR

J4 EIA
COMMUNICATIONS
CONNECTOR

J8 VIDEO IN
CONNECTOR
J9 VIDEO OUT
CONNECTOR

J7 KEYBOARD
CONNECTOR

MA-1995

Figure 4-2
Advanced Video Option
Installation

OPTIONS

20 rnA CURRENT LOOP OPTION - VT1XX-AA
The 20 mA Current Loop Option allows the VT100 to connect directly to the host
computer over a short distance without using a modem. The specifications for the
20 mA Current Loop Option are located in Chapter 2 of this manual under interface information.
20 rnA Current Loop Option Installation
Use the following procedure to install the 20 rnA Current Loop Option:
1.

Remove power from the terminal by disconnecting the ac plug.

Unplug the keyboard.

Unplug any connectors from the composite video input/output jacks.

Disconnect the communications cable.

With a blade-type screwdriver loosen the four captive screws holding
the access cover; then remove the cover.

Set the TRANS switch to the NORMAL position (Figure 4-3). (If the
terminal must provide current on the receive line. set the switch to the
ACT position.)

Set the REC switch to the NORMAL position (Figure 4-3). (If the terminal must provide current on the receive line set the switch to the ACT
position.)

Connect P5 to J5 on the terminal controller board (Figure 4-4).

Perform the 20 mA Current Loop Option Checkout.

CAPTIVE
SCREWS (4)

.---_ _ _ ACCESS
COVER

20mA

CURRENT
____ LOOP BOARD

Ir::::::::::J .

TRANSMIT
LINE
SWITCH
RECEIVE
LINE
SWITCH

20mA
COMMUNICATIONS

Figure 4-3
20 rnA Current Loop Option

C.iiiiiiii~iii:::::~~L- --CON N ECTOR MA-1996

OPTIONS

20 rnA Current Loop Option Checkout
The VT100 contains an internal test called the data loopback test. In the data
loopback test the VT100 transmit and receive lines are connected to each other
via a special external connector. A predefined set of characters are then transmitted. The terminal receives the characters and compares them to the characters
transmitted. If the characters do not match an error is then flagged.
Use the following procedure to check out the operation of the 20 mA Current Loop
Option.
1.

Disconnect the terminal from the communications line.

Remove the terminal access cover containing the 20 mA current loop
board; place both of the switches in the NORMAL position. Reinstall
the access cover.

Connect the 20 mA loopback connector (PN 70-15503-00) to the
Mate-N-Lok connector mounted to the bottdm of the access cover.

Place the terminal in ANSI-compatible mode (in SET-UP B group 2
switch 3 equals a 1).

Type the following sequence to perform the data loopback test.

ESC [ 2; 2 y
When the test is performed, the screen clears and the message "WAIT"
is displayed in the upper left corner of the screen. The entire test takes
approximately six seconds to run.

NOTE
The data loopback test can be
repeated indefinitely by typing
ESC [ 2; 10 y. This test ends
only when an error is detected
or the terminal power is
turned off.

WITH 20mA
OPTION

CONTROLLER
BOARD

MA-1997

Figure 4-4
Terminal Controller Board

70 OPTIONS

A loopback error is shown by "8" being displayed in the upper lefthand
corner of the screen. If an error is detected, check the 20 mA board
connectors and switch settings and then repeat Step 5. If the error
persists, contact your service organization.

Once the test is complete return the 20 mA current loop board
switches to the original positions, remove the loopback connector, replace the access cover, and reconnect the terminal to the communications line.

COMMUNICATIONS CABLES
The following communication cables are available for use with the VT100. Contact
your local DIGITAL sales office for ordering information.

Table 4-1
Available
Communications
Cables

Cable Number

Length

Connector Types

Purpose

BC22A-l0

10 ft.

RS-232 (female) to
RS-232 (femaie)

Null modem; direct connection between
vT100 and line unit (6 conductor cabie).

BC22A-25

25 ft.

RS-232 (female) to
RS-232 (female)

Null modem; direct connection between
VT100 and line unit(6 conductor cable)

BC22B-l0*

10ft.

RS-232 (female) to
RS-232 (male)

(i4 conductor cable)

25 ft.

RS-232 (female) to
RS-232 (male)

Extension; connect VT100 to a modem
(14 conductor cable)

variable

RS-232 (female),to
RS-232 (female)

,Null modem;, direCt connection between
VT100 and line unit

BC05D-xxt

variable

RS-232 (female) to
RS-232 (male)

Extension; connects VT100 to a modem

BC05F-XX:j:

variable

Mate-N-lok

20 rnA; direct connection between
VT100 with a 20 rnA option installed
and a line unit.

BC22B~25*

Extension; connect VT100 to a modem

* This cable cannot be used with a DF01-A Acoustic Coupler. Use cable BC050-XX in its place.
tFOf use with a OF01-A Acoustic Cou~ef. Pin 23 of this cable must be disconnected.
:j:A BC05F-15 cable is shipped with the VT1XX-AA option.

APPENDIX A
ANSI DEFINITIONS
AND NOTATION
ANSI DEFINITIONS
Active position - The character position on the visual display that is to display the
graphic symbol representing the next graphic character.
ANSI mode - A VT100 mode in which it recognizes and responds only to escape
sequences whose syntax and semantics are in accordance with AN 51 specifications.
Character position -That portion of a visual display which is displaying or is
capable of displaying a graphic symbol.
Control - A control character. an escape sequence, or a control sequence that
performs a control function.
Control character - A character whose occurrence in a particular context initiates,
modifies, or stops a control function.
Control function - An action that affects the recording, processing, transmission,
or interpretation of data.
Control sequence - A sequence of characters that is used for control purposes to
perform a control function, that begins with the control sequence introducer (C51)
control, and that may contain a parameter string.
Control sequence introducer (CSI) - An escape sequence that provides supplementary controls and that is itself a prefix affecting the interpretation of a limited
number of contiguous characters.
Control string - A string of characters that is used to perform a control function
and that is delimited by an opening and closing delimiter control.
Cursor - A visual representation of the active position which is either a blinking
reverse-video or blinking underline.
Cursor control - An editor function that moves the active position.

ANSI DEFINITIONS AND NOTATION

Default - A function-dependent value that is assumed when no explicit value, or a
value of 0, is specified.
Display - The current active area of the screen, i.e., the area inside the scrolling
region, or the entire screen, depending on the origin mode.
Editor function - A control that affects the layout or positioning of previously
entered or received information in a printing or cathode ray tube device and that is
intended to be interpreted and executed without remaining in the data stream.
(See format effector.)
Escape character (ESC) - A control character that provides supplementary characters (code extension) and that is itself a prefix affecting the interpretation of a
limited number of contiguous characters.
Escape sequence - A sequence of characters that is used for control purposes to
perform a control function and whose first character is the escape (ESC) control
character.
Final character - A character whose bit combination terminates an escape or
control sequence designated by F.
Format effector - A control that affects the layout or positioning of information on
the screen and that may remain in the data stream subsequent to interpretation
and processing. (See editor function.)
Graphic character - A character, other than a control character, that has a visual
representation normally handwritten, printed, or displayed.
Home - The character position at the origin. [See origin mode (DECOM).]
Intermediate character - A character whose bit combination precedes a final
character in an escape or control sequence.
Numeric parameter - A string of bit combinations that represents a number,
designated by Pn.
Parameter - (1) A string of one or more characters that represent a single value:
(2) The value so represented.
Parameter string - A string of characters that represent one or more parameter
values.
Selective parameter - A string of bit combinations that selects a subfunction
from a specified list of subfunctions, designated by Ps. In general. a control sequence with more than one selective parameter causes the same effect as several
control sequences, each with one selective parameter, e.g., CSI Psa; Psb; Psc F is
identical to CSI Psa F CSI Psb F CSI Psc F.
VT52 mode - A VT100 mode in which it recognizes and responds only to escape
sequences which DEC VT52 type terminals use.

ANSI DEFINITIONS AND NOTATION

NOTATION
I - An intermediate character in an escape sequence or a control sequence, where
I is from 408 to 578 inclusive.

F - A Final character in:
1.

An escape sequence, where F is from 608 to 1768 inclusive.

A control sequence, where F is from 100s to 1768 inclusive.

Pn - A numeric parameter in a control sequence, where Pn is a string of
zero or more characters from 608 to 718 inclusive.
Ps - A variable number of selective parameters in a control sequence,
with each selective parameter separated from the other by 738. Ps is a
string of zero or more characters from 608 to 718 inclusive and 738.
Example: The format of an escape sequence as defined in American
National Standard X 3.41-1974 and used in the VT100 is:

ESC I ... I F
Where:
1.

ESC is the introducer control character (338 ) that is named escape.

I ... I are the intermediate bit combinations that mayor may not be
present. I characters are bit combination 408 to 578 inclusive in both 7and 8-bit environments.

F is the final character. F characters are bit combinations 608 to 1768
inclusive in escape sequences in both 7- and 8-bit environments.

The occurrence of characters in the inclusive ranges of 08 to 378 within
an escape or control sequence, is technically an error condition whose
recovery is to execute immediately the function specified by the character and then continue with the escape sequence execution. The exceptions are: If the character ESC occurs, the current escape sequence is
aborted, and a new one commences, beginning with the ESC just received. If the character CAN (308) or the character SU B (328) occurs,
the current escape sequence is aborted.

APPENDIX B
7-BIT ASCII CODE
Octal
Code

000
001
002
003
004
005
006
007
010
011
012
013
014
015
016
017
020
021
022
023
024
025
026
027
030
031
032
033
034
035
036
037

Char

NUL
SOH
STX
ETX
EaT
ENO
ACK
BEL
BS
HT
LF
VT

FF
CR
SO
SI
OLE
DC1
DC2
DC3
DC4
NAK

SYN
ETB
CAN
EM
SUB
ESC
FS
GS
RS
US

Octal
Code

040
041
042
043
044
045
046
047
050
051
052
053
054
055
056
057
060
061
062
063
064
065
066
067
070
071
072
073
074
075
076
077

Char

#
$

%
&

0
2
3
4
5
6
7
8
9

<
=

>
?

Octal
Code

100
101
102
103
104
105
106
107
110
111
112
113
114
115
116
117
120
121
122
123
124
125
126
127
130
131
132
133
134
135
136
137

Char
@

A
B
C
0

E
F
G
H
J

K
L
M
N

a
P
0

R
S
T
U
V
W

X
Y
Z

1
/\

Octal
Code

140
141
142
143
144
145
146
147
150
151
152
153
154
155
156
157
160
161
162
163
164
165
166
167
170
171
172
173
174
175
176
177

Char

a
b
c

e
f

9
h
j

m
n
0

p
q

s
u
v

w
x
y

DEL

APPENDIX C
FILL CHARACTER
REQUIREMENTS
Fill characters are required to keep the VT100 synchronized with the host computer when the XON/XOFF control codes are not used. Table C-1 shows the
VT100 fill character requirements for every receive speed at which the terminal is
capable of operating. No entry in a column indicates that fill characters are not
required in that specific case.

Table C-1

Control Function

Fill Character
Requirements

Receive

19200

Baud
Rate

9600
4800

384
192

243
122

90
45
23
17

60
30

6
6

3600

2400
2000

48
40
36
24
12

46
30
25
23

8
4
3
2
2

1800
1200
600
300

200

150
134.5
110

3
2

3
2
2

4
2

OTHER TERI\IIII\JALS
The terminal is the link between the user and the power of the computer. Often the
right terminal. or the right enhancement to the terminal can make your work easier, more efficient or more cost effective. For that reason, DIGITAL offers a full
range of video and teleprinter terminals and options that can help you tackle any
application.

30 CHARACTER PER SECOND KEYBOARD PRINTER
LA34/LA38 DE Cwriter IV
Everything about the 300 baud desk-top terminals adds up to convenience. They
are smaller, lighter and quieter than many typewriters. They have sculptured, typewriter-like keys and a cartridge for simple ribbon changes. All features are set at
the keyboard, including four character width adjustments. They also have automatic self-test diagnostics.

180 CHARACTER PER SECOND KEYBOARD PRINTER
The LA 120, DIG ITAL's fastest hardcopy terminal, offers better throughput than
that of terminals with faster print speeds. The 180 character per second printhead
prints bidirectionally and always seeks the next print position. The LA 120 offers an
unexcelled range of standard features. Over 45 keyboard-selectable features are
offered. These features include variable font sizes, tabs, form length and many
other features previously available only as options. To guide the operator through
the myriad of possible configurations, the carefully human-engineered terminal
uses mnemonic commands, a prompting LED display, a special decal and a convenient pocket-sized operator card.

INTELLIGENT VIDEO TERMINAL
At the head of the VT100 class are DIGITAL'S intelligent PDT-11 terminals. The
PDT family includes three program mabie data terminals; the PDT -11/110, the
PDT-11/130, and the PDT 11/150. With their PDP-11 compatible processors and
RT-11 operating system, the POTs permit you to draw on a wide range of existing
software. Local mass storage is available on the PDT -11/130 in the form of 511 K
bytes of storage provided in dual mini-cartridges. Housed within the same VT100
shell, these mini-cartridges are file-structured system devices. The PDT -11/150
lets you combine the functionality of the PDT -11 with the dual floppy disk storage
of any DIGITAL terminal. With its four ports, the PDT-11/150 allows considerable
system expansion. Add a terminal controller if you want the flexibility of up to four
terminals. For hardcopy, add a printer to the printer port. There is a third port for
an EIA link to a host computer.
There's lots more to tell about these terminal products. If you would like more information on any of these products just fill out the postage paid card and drop it in a
mailbox or write:
DIGITAL EQUIPMENT CORPORATION
Components Group
One Iron Way
Marlboro, MA 01752
ATTN: MARKETING MANAGER
MR2-2/M70

Reader's Comments
VT100 USER GUIDE
EK-VT100-UG-002
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