Download Digital Equipment Corporation 220240 Programming instructions

CHAPTER
SYSTEM
1
DESCRIPTION
Summary
The Digital Equipment Corporation Programmed Data Processor-4 (PDP-4)
is designed to be the control element in an information processing system.
PDP-4 is a single address, parallel, binary machine with an 18-bit word
length using l’s or 2’s complement arithmetic. Standard features of the
machine are stored program operation, a random access magnetic-core
memory, a complete order code, and indirect addressing.
Flexible, high-capacity input-output capabilities of
operate in conjunction with a variety of peripheral
forated-tape readers and punches, punched-card
Teletype printer-keyboard,
line printers, magnetic
analog-to-digital converters.
the PDP-4 enable it to
devices, such as perreaders and punches,
tape transports, and
The machine is completely self-contained, requiring no special power
sources, air conditioning, or floor bracing. From a single source of 115volt, 60cycle, single-phase power, PDP-4 produces circuit operating dc
voltages of -15 volts (%l) and +lO volts (&l) which are varied for marginal checking. Total power consumption is 900 watts. It is constructed
with standard DEC 4000 series system modules and power supplies.
Solid-state components and built-in marginal checking facilities insure
reliable machine operation.
System
Description
The basic PDP-4 system is shown diagramatically in Figure 1. Three po tions of the system are delineated according to function: the Arithmet c
and Control Element, the Interface, and the Input-Output Equipmen I .
Information originates not only from peripheral devices but can be entered
manually and modified at the Operator Console.
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