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XX-985E2-0F

2000

22 pages

Original

3.5MB

Document:	The New PDP-12
Order Number:	XX-985E2-0F
Revision:	0
Pages:	22
Original Filename:	dec.pdp-12.1963.102646098.pdf

OCR Text

IIGITAL EQUIPMENT CORPORATION
-

Digital's PDP-12 isi a complete computer system.
It is designed as e'simpla-to-operate toot for a wide
varlaty sf research and real-time data-handling
applications.
Performance characterfstics of the PDP-I 2 have been
optimized around a complete t~ardware/soM~re
,system, rather than around an expandable minimum
processor and memory. The PDP-12 syetern cancegt
works ta the advantage of usem at all levels crf
programming saphlstieetion. By s~rnpllfjring
program tasks, the, PDP-12 frees users from the
rnechantcs of program preparation to concentrfita on
mare creative aspects af their work.
f he following is a brief list of s m n fif:thn
PUP-12's features:
* All new, unified dikplay-based programming system
Automatic program loading from megnetlc tape
Program debugging hardware
Seven by nine inch CRT display with gmphic.and
alphanumeric capability
Largei existing library af applications program
TTL intagtared circuit modules throughout
* LIWCiape (addreiisable bi-directional rnagn4fe .
tape) b r program and data storage
Freestanding cabinet and' cansslie table
@

DIGITAL EQUIPMENT CORPORATION

Analytical Instrumentation
The PDP-12 can be used to acquire and analyze data
from one or more instruments typically used in chemical
or physical analysis. Mass spectrometers, gas chromatographs, chemical analyzers, NMR spectrometers, and
various particle-size counters are a few of the instruments that may be automated through the use of the
PDP-12. This application speeds up the process of obtaining the final data, reduces the number of errors, and
performs a more thorough and accurate analysis than is
possible when computations are done manually. The
PDP-12, with its digital and analog input capabilities for
handling the instrumentation signals and its relay outputs
for instrument control or range switching, helps eliminate
the need for complex special interfaces to several classes
of instruments. The cathode ray tube display, with its
graphic and alphanumeric capability, allows for the effective presentation of not only data and results but operating
instructions which make the PDP-12 easy to use, even
by the unskilled operator. The establishment of a question
and answer dialogue between the computer and operator
allows for an interaction not permitted by most small
general purpose computers.

also completely buffered from the central processor. This
allows the program to continue doing its computation
while the tape units search for the proper block number
and accomplish the transfer of data directly from memory
onto magnetic tape, thereby freeing the processor of any
tape handling routines. While the buffered CRT display
is plotting data on its screen, the processor is free to .*
continue with other tasks.
All these PDP-12features enhance the machine's through- '
put capabilities (acquiring and transferring data to some
intermediate storage device, such as digital magnetic
tape). Throughput rates as high as 7.5 thousand words
per second are possible with burst handling capability up to a maximum of 50,000 words per second. This high
throughput capability allows the PDP-12 to handle the
majority of signal processing chores encountered in real- :
time laboratory situations.

A library of programs is available to handle a wide variety
of typical signal processing applications, such as data
averaging, Fourier analysis, time interval histograms,
general data acquisition, as well as programs for scannina
data already acquired and placed on magnetic tape.

S i g d Processing

Educetion

Typical signal processing requirements within the general
laboratory involve the manipulation of data through the
use of such mathematical tools as averaging, time interval measurements, frequency analysis, and correlation
techniques. The PDP-12 is well suited for this type of
data acquisition and analysis for many reasons. It has a
buffered analog-to-digital converter which allows analogto-digital conversion to be initiated by an external source,
such as a clock, and does not require any intervention on
the part of the processor during the actual conversion
of the analog signal. The results are then immediately
available to the processor within one machine cycle (11/2
microseconds). This feature allows the processor to continue doing useful work while the actual analog-to-digital
conversion process is independently taking place. The
data that is being acquired and processed may be transferred to digital magnetic tape, the operation of which is

It has become apparent to educators oveithe past several
years that no discipline remains untouched by the ravolul
tion in the computer sciences. The use of computers w
problem solving took (camputm extknded instruction]
is being adopted b y universities, Junior colleges, and high
schools throughout the country. In technical curricda
computer usage is being taught as part of process control courses for chemical engineers, computer science
courses for electrical engineers, instrumentation cwrsee
for medical students, and laboratory courses for speech
students, just to name a very few. The computer in the&
applications is a new and powerful tool to assist in pr&_
lem solving. The hands-on interactive concept of %& ,
PDP-12 makes it particularly well suited for this type sf
environment. The use of a graphics display through which
the machine and operator can communicate, coupled with
the ease of operation inherent in its design, has put t
'

. .

PDP-12 and its predecessors, LINC-8 and LlNC computers, in the forefront of computer extended instruction
in many universities and technical schools around the
world. Extending the computer concept slightly further,
t o such things as computer mediated instruction and
guidance testing, brings into focus another ideal application for the PDP-12. Author-like languages and learning
programs have already been written on predecessor
machines and are available for experimental work in this
field. These software packages, plus inexpensive bulk
storage via LINCtape, and ease of programming, make
the PDP-12 a highly flexible tool for the innovative
researcher.

Bib-Medicine

~io-me'dicalresearch is an application to which the PDP12 is ideally suited. In psychological research, operant
behavior, and related fields it can control experiments,
record events, and analyze results. It has the capability
of handling data inputs and outputs for such things as
reinforcements studies. In experiments where humans
or animals are presented stimuli to which they respond
by pushing buttons or levers, the computer can be used
to analyze these results on-line, using standard statistical
techniques. The relay contact outputs, digital signal inputs, and manual sense switch branching capabilities
from the console make the PDP-12 a powerful and flexible
tool for the psychological researcher. The use of inexpensive magnetic tape storage (LINCtape) for both data
and programs, coupled with an existing library of statistical packages, graph plotting packages, as well as
interviewing programs, providesan excellent starting point
from which other programs may be written, to suit the
specific needs of the individual researcher.
In physiological studies, the PDP-12 has the capability
of handling both analog and digital signals, providing realtime analysis of the information and control of the experiment from which the data is being derived. Programs
for handling EKG, EEG, and evoked potentials have
already been written for predecessor machines and exist
both within the DEC program library and the Digital
Equipment Corporation User's Society Library.

Hospital Systems
In the clinical chemistry laboratory the PDP-12's turn-key
system provides better patient care, reduces costs, helps
relieve the load on the limited number of technicians,
handles more tests, and provides better and faster information to the medical staff. This system interprets and
processes data simultaneously from up to 15 analytical
instruments. It gives automatic readouts, allows continuous monitoring of the process, files and stores results,
and does all of the result calculations. A patient filing
system allows an accumulative patient summary to be
maintained. The computer is able to keep detailed records
on each patient, print out periodic summaries, print out
summaries on a particular patient on demand, even while
it is logging data. At regular intervals the computer is capable of forwarding billing information based upon the tests
performed to the accounting department's computer. This
will allow the increased work load and record keeping to
be performed without imposing a staggering task on the
billing department or cause the hiring of additional personnel. The PDP-12 Clinical Laboratory System pays for
itself in time otherwise spent in tedious and time-consuming calculations. Also, the operator needs no special
training in computer programming. All interfaces and software are supplied by Digital in one easy-to-use turn-key
system.
The PDP-12, with its inherent ease of operation, is an ideal
tool for use in patient monitoring and patient interviewing.
In the patient monitoring situation, EKG, EEG, respiration,
etc. can all be handled by the PDP-12 A / D converter and
multiplexer. In patient interviewing, the CRTdisplay allows
a question and answer dialogue to be established between
the patient and the computer while allowing summary
printouts via the Teletype. Programs have already been
written on predecessor machines for general medical
histories and are actually in use in clinical environments.
Many new clinical diagnosis systems are being planned
and designed. Cytology, multi-phasic screening, and
many other systems will benefit from the flexibility and
ease of operation of the new PDP-12, with its inherent
data gathering capabilities, utilizing digital and analog
inputs, as well as its alphanumeric and graphic display
capabilities.

Due to the unique capability of the PDP-12 to execute
two complete instruction sets (the LlNC instructions and
the PDP-8 family of instructions) a substantial amount of
field-proven software is immediately available for use on
this system. This software consists of the entire library
of PDP-8 programs (both systems programs and applications programs). It is also compatible with the LlNC and
LINC-8 software, especially in regards to their application programs. To simplify the general programming task
and to optimize the advantages of a dual order-code
system, a special operating system has been developed.
This operating system - a unified, display-based system
- represents an ultra-powerful, general-purpose assembler, editor, and monitor for both PDP-8 and LlNC programming.

Unified Display-Based Operating System
This sophisticated operating system assumes the use of
two tape transports and a display as integral parts of the
system. The operating system Is composed of an editor,
an assembler, a monitor, and data-handling ro'sutmes far
performing the typical fundions required in program
development.
The operating system is normally i.n the editor mode,
awaiting input information that may be entered via the

Teletype, magnetic tape, or paper tape. The command
structure of the operating system allows simple and
straightforward commands to perform operations such
as manipulation (adding, changing, or deleting) of manuscripts, filing of information, copying of manuscripts and
data, editing, listing, searching, and assembling.
The editor allows editing on a line-by-line or on a character basis by the use of a controllable cursor on the
display. The editor allows random access to any character
or line being edited in the text, without resorting to any
scheme using paging techniques. The assembler is a
two-pass program that is called directly via the monitor.
The assembler utilizes additional core and/or disk
storage for handling symbols that it cannot contain within
the initial 4K of memory. The concept is to maximize the
speed at which the assembly can be made. The assembler
will handle both PDP-8 and LlNC instructions. Six character symbols and tags are used throughout.

4K FORTRAN Compiler
The 4K FORTRAN compiler lets the user express problems in a mixture of English words and mathematical
statements. It reduces the time needed for program
prepamtion and enables users with little or no knowledge
of the wmputer's organization and operating language
to write effective programs. FORTRAN language consirts
of b u r general types of statements: arithmetic, logicvr
control, and inputjautput. FORTRAN functions include
addition, sutxtraction, multiplicatian, division, sine, cosine,
arctangent, square root, natural logarithm, and exponentiation.

8K FORTRAN Compiler

Display-Based Editor

[requires 8K of memory and high-speed paper tepe)
The 8K FORTRAN compller translates a source program
into a symbolic language, and than the symbolic version
oT the program is translated into relocatable binary code,
the Janguage of the computer. The binary code is punched
anto paper tape and then reloaded into the computer for
running the program. The 8K FORTRAN system features
USA Standard FURTRIWV slyntrrx; subroutines; two levels;
of subscripting; function subprograms; input/output

supervisors; relocatable output loaded by the Linking
Loader; COMMON statements; I, F, E, A, X, and H format
specifications; and arithmetic and trigonometric library
subroutines.
The 8K FORTRAN system consists o f the two-pass
FORTRAN compiler, Linking Loader, Run-Time Monitor,
and a library of subprograms. The system requires 8K of
core memory, an ASR33 Teletype, and a high-speed paper
tape reader and punch. The compiler utilizes all available
core to 32K and is page transparent.

FOCAL
FOCAL (Formula CALculator) is a new conversational
~ 0 S S r l i k e calculator and programming language developed by Digital. FOCAL has proven to be a powerful
tool for solving complex calculations. Of equal importance
is FOCAL'S role as a teaching aid. A computer novice
can begin doing useful work within a few hours using
straightforward, simple English commands. Programs can
be checked and modified as they are prepared, and
FOCAL will tell what went wrong i f an error is made.
FOCAL features 14 functions, automatic error tracing,
character editing, and the power to solve six-level simultaneous equations. FOCAL is available in three versions
- 4K, 8K, and 8K Four User. 4K FOCAL uses field zero
to store the FOCAL program, the user's program, and
the user's variables. 8K FOCAL uses field zero to store
the FOCAL program and the user's variables, and uses
field one to store the user's program. This allows for
storage of much larger user programs. Four User 8K
FOCAL, with the proper hardware to connect four Teletypes, gives four users each the power of 4K FOCAL
from one computer.

a maximum of 4096 sweeps, thus providing a technique
for obtaining a valid signal from a noisy environment.
Computation of standard deviation, confidence levels, and
trend, plus calibration and plotting routines, are included.
A dialog is established between the user and the set-up
program with the system CRT display and Teletype.

Floating Polrrt Packages
Floating point packages permit the PDP-12 to perform
arithmetic operations that could not otherwise be done
without the addition of costly hardware. In addition to
increasing accuracy, floating point operations relieve the
programmer of scaling problems common in fixed-point
operations. This is a particular advantage to the inexperienced programmer. The floating point subroutines
and interpreters permit the programmer to encode arithmetic operations to either 6 or 10 decimal digits of precision as easily as though the machine had floating point
hardware. The operations implemented by the floating
point packages include addition, subtraction, multiplication, and division. Other functions in the package are
sine, cosine, square root, logarithms, arctangent, and
exponentiation.

Signal Averaging Program
Signal Averaging Program (requires DW12 and AX08
peripherals) allows for handling of up to 1024 data points
per epoch (sweep) and the averaging of this data over
*lOSS is the trade mark and service mark of The Rand
Corporation

Demonstration Program - simulates a simplified model of the
basilar membrane in the inner ear.

Fixed-Point Mathematical Routlnes
The PDP-12 program library maintains a set of mathematical function routines which perform the following
operations in both single and double precision: addition,
subtraction, multiplication, division, square root, sine,
cosine, arctangent, natural logarithm, and exponentiation.
A library of analytic procedures is available which makes
readily programmable trigonometric functions, logarithm
operations, and procedures such as analysis of variance
or fast Fourier transform.

DATA PROGRAMS
(require PDP-12A LlNC system)
DATA-12 - This program retrieves, displays, and stores
individual data blocks from magnetic tape and provides
the user with a repertoire of mathematical operations
for manipulating this data. These operations include high
and low pass filtration, differentiation and integration,
attenuation and amplification, inversion, addition of a

FRQANA Data Program

ing waveforms are continuously displayed.
FRQANA - This program performs a frequency analysis
of 512 points of data, and resolves the resulting spectrum
into 64 components. The sine, cosine, and rms spectra
are subsequently displayed and can be scaled. A resynthesis from the spectra can then be performed to provide
a comparative display of the original data and the resynthesized waveform.
CURSOR - This program will display on the scope the
signal samples from a designated analog input channel
or data read into core memory from magnetic tape. Two
data files, each 256 points in length, can be handled by
CURSOR. A movable cursor, controllable from the front
panel, is used to examine the data and display the absolute value of the amplitude.

GRAPHA
This program allows data to be retrieved
from magnetic tape and displayed, as well as a graph to

CURSOR Data Program

be composed for this data with appkpriate lettering and
axes. The graph is assembled on the display and the
finished product may be photographed, plotted on an
incremental plotter, or saved on magnetic tape for future
reference.

MAGSPY This program provides a moving window for
scanning data stored on digital magnetic tape. The data
is displayed on the scope and can be scanned at a rate
determined by a potentiometer setting. The data can be
interpreted either as binary numbers or packed characters.

Utility Programs
A number of utility programs are supplied with the PDP12. They include programs to provide printouts or punchouts of core memory content in octal, decimal, or binary
forms, as specified by the user. Subroutines are provided
for octal or declmal data transfer and binary-to-decimal,
decimal-to-binary, and Teletype tape conversion. Other
utility packages include:

Isometric Plot Subroutine
These programs provide for
plotting a function of two variables, f (x, y), isometrically
on a digital plotter.
Message Display Subroutine -This is a basic subroutine
for displaying lines of text on the scope. It is selfcontained, with matrices for all digits, letters, and special
characters.
Question and Answer Subroutine -This is a general subroutine used to display a page of text on the scope.
Question marks may be displayed and replaced with
responses from the keyboard. The information entered
in this manner may be recovered by a subsequent portion
of the user's program.

GRAPHA Data Program

Maintenance Programs

MAGSPY Data Program

A complete set of standard diagnostic programs simplifies and expedites system maintenance. Program descriptions permit the user to test effectively the operation
of the computer for proper core memory functioning and
proper execution of instructions. Diagnostic programs
are provided to check the performance of standard and
optional peripheral devices.

The PDP-12 is a single processor computer system which
executes instructions from either of two order codes. The
PDP-12 directly executes programs written for the PDP-8
or LlNC computer systems.
The PDP-12 combines a totally new hardware organization with advanced system software to make optimal use
of its hardware capabilities. Processor control is switched
between modes by a single instruction or by console
action. All instructions or console functions are directly
executed by hardware.
The PDP-12 is a faster, more powerful, and less expensive
successor to the LINC-8. Its totally redesigned tape units,
display, analog-to-digital converter, and prewjred realtime clock offer many new benefits while maintaining program compatibility with previous systems. The input/
output bus is compatible with most integrated circuit
levels. It operates directly from either processor mode
and is identical to those on the PDP-8/L and PDP-8/1.

PDP-12 features:
4096 words, 12-bit core memory with 1.6 microsecond
cycle time
Full power processor prewired for the addition of a
large number of options and peripherals
Low-cost core memory expansion to 32,768 words, lowcost mass storage with DECdisks, and IBM-compatible
synchronous and incremental magnetic tape
Worldwide, dependable field service
Over 4,000 compatible PDP-8, LINC, and LINC-8 family
computers in use forsharing programs through Digital's
users group (DECUS)
Single cycle and three cycle direct memory data break
facilities, standard
All active registers continually displayed
Signed i u l t i p l e instrllrtion, standard
Analog
Inputs

Preamps

~
~plexer

-t
8

KNOBS

t
&
Hold

Fifteen auto-index registers, standard
LlNC feature to facilitate multiple precision arithmetic
Both two's complement and one's complement arithmetic.
24-bit console switch register
Six sense switches
Complete with thirty inch free-standing cabinet, console table, ASR33 teleprinter including paper tape
reader and punch
Twelve digital sense line inputs, standard
Six single-pole double-throw relay outputs

ELECTRICAL
Power requirements:
15 amperes, average, at 115 volts, 60 cycles single phase.
(Other line voltage and frequency ratings are available)
Power requirements:
Under 2 kilowatts
110 bus levels:
Ground and $3 volts

PHYSICAL
Standard cabinet size:
71" high, 33" wide, 35" deep (including console)
Table:
30" wide, 20" deep
Teletype size:
33" high to top of console, 22%" wide, 18%" deep
Weight:
700 Ibs.

ENVIRONMENTAL
Temperature:
40°F to 105OF ambient
Humidity:

A/D
A

i 4

Console

Central

option peripherals
rncluding

D~sks
IBM Compatible Tape
Data Acqulslt~onEqu~pment
H~gh-SpeedPaper Tape
Card Readers
Data Comrnun~cations
Clock

u
Memory

SYSTEM BLOCK DlAGRAM

Additional
Memorv B Control

LlNC INSTRUCTION FORMATS
OPERATION CODE
f

Coda Mnemonlc
-

ADDRESS

Full Addrass Class

OPERATION CODE

T4PE CLASS

FIRST WORO
MOTION
BIT I11

MEYORY BLOCK IMBLK) BITS

BCL

1600

BSE

1640

BCO

0017

COM

UNIT
BIT I#)

T o p Instruction

The following lnstructlons are used In the LlNC mode
The LlNC Order Code 1s bulk on eleven basic functions
as shown In the llst that follows

ADD
ADA
ADM
LAM

Function

MULTIPLY
Signed multiply
Load AC with MQ

LDA
LDH

LOAD
Load AC, full register
Load AC, half register

STC
STA
STH

STORE
Store and clear AC (IK address)
Store AC
Store half AC

ROL N
ROR N
SCR N

SHIFTIROTATE
Rotate left N places
Rotate rlght N places
Scale rlght N places

HLT
NOP
CLR
SET
JMP
DJR
ESF
SFA

ATR
RTA
SAM N
DIS
DSC

Time (psec)

ADD
Add memory to AC (IK address)
Add memory to AC
Add AC to memory
(sum also in AC)
Add link and AC to memory
(sum also In AC)

MUL
QAC

OPERATE
Halt
No operation
Clear AC and Link
Set register N to contents of
register Y
Jmp to register Y (IK address)
Disable JMP return
AC to spec. fctn. register
Spec. fctns. register to AC

LOGICAL OPERATIONS
Blt clear (any combination of
12-bits, logical AND)
Bit clear (any combination of
12-bits, inclusive OR)
Bit complement (any
combination of 12-bits, exclusive OR)
Complement AC

TAPE BLOCK IBNI BITS

SECOND WORD

Code
Mnemonic
-

Time ( p w )

SKIP
Sklp next Instruction ~ f :
AC equals memory register Y
SAE
Rlght half AC unequal to specified
SHD
half of memory register Y
Sense switch N is set
SNS N
AZE
AC equals zero
APO
AC contalns posltlve number
0
LZE
Llnk b ~equals
t
External level N IS present
SXL N
KST
Keyboard has been struck
FLO
Add overflow is set
Blt 11 of MQ register equals 1
Rotate memory register r ~ g hone
t
place, then if blt 11 of Y equals
0 skip next Instructlon
IBZ
Between blocks on mag tape
SKP
Unconditional skip
XSK
Index memory register Y, skip
when contents of Y equal 1777.
STD
Tape lnstructlon done
TWC
Tape word completed

INSTRUCTION

INDEX REGISTERS

1540

Function

RSW
LSW
PDP
IOB

0640
OgOO

LDF n
LlF n

RDE
RDC
RCG
WRI
WRC
WCG
CHK
MTB
AX0
XOA
TAC
TMA

INPUT-OUTPUT
AC to relay buffer
Relay buffer to AC
Sample analog chan N
Dlsplay pomt on oac~lloscope
Dlsplay character on oscilloscope
(2x6 matrix)
Rlght switch register to AC
Left switch register to AC
Transfer to PDPB program control
Execute ~nput-outputBus xfer

MEMORY
Change data field memory bank to bank n
Change instruction held memory bank
to bank n

LlNC TAPE
Read one block into memory
Read and check one block
Read and check N consecutive
Wrlte one block on tape
Write and check one block
Write and check N blocks
Check one block of tape
Move tape toward selected block
AC to Ext. operations buffer
Ext, operations buffer to AC
Tape AC register to A€
AC to tape control register

3.2 plus tlme
dependant
on tape
positlon

Indirect addreaslng adds 1.6 lrsec to given
instructign times

The concept of a useful computer system as embodied by
the PDP-12 means the optimization of the systems hardware and software around a specific set of input/output
devices. These devices include two magnetic tape transports, a large screen CRT display, an analog-to-digital
converter and multiplexer, as well as relay closure outputs and sense line inputs. The ability to handle this
specific set of input/output devices is designed into the
basic instruction set of the PDP-12 and is not considered
part of the general 1/0 bus facility, but rather an integral
part of the system. This allows more efficient handling
of informatlon to and from the user devices.

LlNCtape Control TC12 and
TUB5 Transports
Digital's PDP-12 LlNCtape control is a totally independent
tape processor which operates directly into memory on
a cycle-stealing basis with the central processor. This
system provides an addressable magnetic tape facility for

high-speed loading, read-out, and program updating. A
maximum LlNCtape configuration with eight TU55 transports, each carrying a tape of standard format to take
131,000 words, can provide over one million words of
rapidly accessible storage to the PDP-12. All LlNCtape
instructions are directly executed by the TC12 control.
The user may choose to have programming proceed or
pause during tape transfers, which occur at the rate of
one 12-b~tword every 100 microseconds.
The LlNCtape instruction set includes instructions to read,
write, and check individual blocks or groups of tape
blocks. Each instruction is complete. The tape control
does all searching, as well as actual data transfers, without program intervention or the use of memory locations
for word count and current address counters.
In addition to the defined LlNCtape instructions, an extended addressing mode is provided which allows up to
2048 blocks of any length to be transferred, beginning
with any program specified core location. This provides
for a maximum of over 200,000 12-bit words per reel of
tape.

A controller option TC12-8 is available which allows the
PDP-12 to read or write DECtape. This allows for the
transfer of data for the purposes of moving information
from DECtape to LINCtape, and vice versa, to provide
compatibility with other DECtape units on other machines.

LlNC Scope Control VC12 and
VR12 Display
The PDP-12 display system offers the user direct interaction with a small computer in a way previously unobtainable at a reasonable price.
The VR12 point plotting display offers an 11" diagonal
viewing surface (58.5 square inches). The very bright P31
Phosphor allows viewing under normal ambient lighting
conditions.
The VC12 buffered display control makes optimal use of
the features of the VR12 display scope. The character
display instruction (DSC) allows up to 400 characters to
be displayed flicker-free in two preset sizes. The display
control has its own buffer registers and allows the computer program to continue after initiating the display
instruction.

The D/A converter outputs of the display control are
buffered, and are capable of driving cables up to 200
feet in length. Two independent intensity channels allow
two simultaneous displays to be driven from the same
computer on two separate scopes.

Analog-to-Digital Converter and
Multiplexer, AD12
The analog-to-digital converter (AD12) includes 16 channels of input through an FET-switched multiplexer which
drives a sample and hold circuit. The sample and hold
output is converted by the 10-bit A/D converter which is
controlled by the LlNC mode SAM instruction. Eight of
the 16 input channels go directly to the potentiometers
which are used by numerous programs as parameter
inputs. The remaining e~ghtchannels go to differential
preamplifiers which provide an input range of _t 1 volt
and an input impedence of 70K ohms. The common mode
rejection of the preamplifiers is nominally 50 and will pass
signals up to 60 KHz. The preamplifiers provide 10,000
per cent overload protection with microsecond recovery
speeds.

The convert time, including multiplexer selection, sample
and hold, and conversion, is approximately 19 microseconds. There are two programmed modes of operation
in which the converter gives the user the option of pausing until conversion is complete or continuing on with

ntains a Sbit register connected
d for controlling experiments or

accumulator and may be interrogated in a similar fashion.
The contact rating is two amperes at 28 VDC. One ampere
at 110 VAC is also acceptable. Contact closure time is
approximately 20 milliseconds.

The PDP-12 has a complete line of peripherals identical
to those offered for Digital Equipment Corporation's
PDP-8/1 and PDP-8/L. Included are two random access
DECdisks, a high-speed paper tape reader and punch,
synchronous and incremental IBM-compatible magnetic
tape, incremental plotter, data communications equipment, and card readers. All of these are easily interfaced
to the PDP-12 in the factory or in the field.

Extended Memory,MC12 and MM8/1
Core memory for the PDP-12 is expanded inexpensively
by the addition of up to seven memory modules of 4096
words each. The first memory expansion, MC12, is designed for mounting within the PDP-12 central processor.
It requires no additional rack space, and up to six additional 4096-work memory modules (MM8/11s) can be
added to the PDP-12, external to the central processor.
The memory cycle time is nominally 1.6 microseconds.

.. .O,

2.
3.
4.
5.
6.
7.
8.
9.

Real-Time Clock, KW22
The KW12 real-time clock is designed to solve a wide
range of programming requirements. The clock consists
of a crystal time base which delivers pulses from a 400
KHertz source at the rate of 400 KHertz, 100 KHertz, 10
KHertz, 1 KHertz, or 100 Hertz. One of these five time
bases, or an external signal, can be used to count the
12-bit clock register. A secortd clock buffer register is
used in conjunction with the clock register to provide
the following three methods of operation:
Time of day - the clock register counts at the time
base rate. Upon a computer signal, the clock is transferred to its buffer and read into the accumulator. The
clock register also provides an overflow flag.
Preset counter - the buffer is loaded with a preset
number from the accumulator. When a clock overflow
occurs, the overflow flag is set, the buffer is transferred
to preset the clock, and the clock continues to count.

Industry Compatible Magnetic Tape Transports
Calcomp Plotter
KSR35 Teletype
CR12 Card Reader and Control
Interface Modules
PC12 High Speed Perforated Tape Reader and Punch
DF32 DECdisk Random Access Disk File
Bell Dataphone (interfaced by a DPl2B)
PDP-12 Single Processor Computer System

10. TU5t .,nsport
1 1. ASR33 Console Teletype
12. AFOl A/D Converter System
13. VR12 Point Plotting Display
14. TR02 incremental Tape Control
15. AX08
16. LP12 High-speed Line Printer
17. Houston Complot

External event timer -the clock counts as in the timeof-day mode. On an external event, the clock is transferred to the buffer and the flag is set. The program
can then pick up the time of event from the buffer
while the counter continues to run. External signals can
also be used to clear the c~unter.There are three such
input channels.

Incremental Platter Control, XY12
Incremental plotter control XY12 operates one of four
models of incremental plotters for 30 inch, 12 inch, or 11
inch paper, and for step sizes of .Ol inch or .005 inches.
All recording (discrete points, continuous curves, or symbols) is accomplished by the incremental stepping action
of the X and Y axes in any one of eight directions. Instructions are used to raise or lower the pen carriage. XY12
plugs directly into the PDP-12, requires no external
mounting hardware, and provides a connector that is
compatible with either Houston Complot or Calcomp
Plotters.

DECdlsk Random Access Disk File, DF32
The DECdisk type DF32 is a low-cost, random-access,
bulk-storage device and control with a capacity of 32,000
words. Average access time is 16.7 microseconds for 60
cycle operation and the transfer rate is 66 microseconds
per word. The DF32 can economically expand the memory
capacity of the PDP-12 by providing up to 131,072 words
of additional storage using three expander DS32 disks.
Data is transferred through the three-cycle data break and
uses theDWO8A 1/0 conversion panel option of the
PDP-12.

Disk, RS08 and Contraller, RF08
Each RS08 Disk and RF08 Controller combination provides storage of 262,144 13-bit words (12 bits plus parity).
Four RS08 Disks can be driven by one controller, for a
maximum capacity of 1,048,576 words. Data transfer rate
on 60-cycle power is 16.7 microseconds per word, and 20

microseconds per word on 50-cycle. Data is transferred
through the 3-cycle data break system and 1/0 conversion panel of the PDP-12. Average access time with a
60-cycle disk is 16.7 milliseconds or 20 milliseconds at
50-cycle power. The RF08 requires the DW08AI/Oconversion panel.

Incremental Tape Cantrsl,
TR02 and Transports
m e TR02 control unit transfers data under program control, between the PDP-12 and incremental tape transports.
Transports are available for incremental write only or for
incremental write and synchronous read. IBM-compatible
7 or 9-channel formats are available with densities of 200,
556,and 800 bpi. The intetface requires no operator control and is expandable to control two tape transports. The
tape transport's reading speed is 25 inches per second.
The incremental writing rate operates at up to 700 steps
per second. Tape reels are 8% inches in diameter. The
TR02 interfaces directly to the positive 1/0 bus of the
PDP-12.

Card Reader and Control, CR12
The CR12 card reader handles standard IBrow, 80column punched cards at 200 cards per minute, in either
alphanumeric or binary mode. Cards are read by column
beginning with column one. The CR12 requires the BA12
option expander panel.

High Speed Perforated Tape Reader and
Punch, PC12
The PC12 includes the PR12 high speed reader and PP12
paper tape punch. It requires the BA12 option expander
panel. The high speed reader is valuable as a program-

ming aid or data input device because of its rapid read-in
of perforated tapes. It photoelectrically senses &channel,
fanfold, perforated tape at 300 characters per second. The
companion paper tape punch operates at 50 cps. Both
include hoppers for handling fanfold tape, and both the
reader and punch are available separately.

AX08
The AX08 integrates in one piece of electronic hardware
a 9-bit analog-to-digital converter, preamplifiers, multiplexer, sample-and-hold, converter, timing error flag,
Schmitt triggers, crystal-controlled and RC clocks, two
12-bit registers, display control, and power supply. Together with a special programming package, the AX08 is
intended to enhance the signal averaging capability of the
PDP-12 general purpose computer system. It requires
the DW12 I/O expander panel.

In little over a decade Digital Equipment Corporation has
become a major force in the computer industry. The
company has grown from a small operation with three
employees and 8,500 square feet to an international corporation with over a million square feet in plants around
the world. From a small manufacturer of digital control
modules the company has become the fourth largest
manufacturer of computers in the world.
More than 4,000 DEC computers have been installed
around the world. In science they have had a tremendous
impact in cutting experiment time and providing the researcher with direct, on-line data reduction. DEC computers control and monitor powerful nuclear reactors,
control X-ray diffractometers, and analyze nuclear spectroscopy data. They monitor medical data, automatically
analyze electrocardiograms, and study the effects of
drugs on the nervous system.

mcus
The Digital Equipment Computer Users Society (DECUS)
gives PDP-12 users access to an expanding library of
utility programs, subroutines, and other programming materials. They can contribute to and receive DECUSCOPE,
a monthly technical newsletter containing user techniques, routines and program summaries. They may attend DECUS annual symposiums and seminars.

Otbef perphera'ls include:
Industry Compatible Magnetic Tape Transports TU20
and Automatic Magnetic Tape Control TC58
High-speed Line Printer LP12 -300 LPM, 132 columns
General Purpose A / D Converter Systems
AFOl - selectable accuracy 6-12 bits with up to 64
multiplexed channels
AF04 - guarded, scanning IDVM. 5uv resolution and
auto-ranging features. 140 db CMR
AM08 - analog multiplexer for up to 1024 channels
Digital-to-Analog Converter AAOI and Control AA05
Data Communications Systems
1BM 360 Data Link DX36
Additional Serial Line (TTY) lnterface DP12
Multiple Teletype System DC02
Interface Modules
Special Systems
Peripheral Expander Panel
1/0 Bus Converter
Power Failure and Turn-on Detection
Teletypes

A world-wide field service staff insures the proper maintenance of DEC machines. One of the company's over
500 field service engineers can be on the spot in a few
hours if a problem develops. If a few hours is not fast
enough, a resident engineer can be located at a site full
time.
For small computer users, DEC also offers unique depot
repair stations. Located at strategic Digital service centers, each station is a complete service lab manned with
full time engineers and equipped with sophisticated test
equipment.

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