RCA 301, Programmer'S Reference Manual

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THE RCA 3 0 1 S YSTEM
L.
r
Morris
I — GENERAL DESCRIPTION
INTRODUCTION
The RCA 301 Electronic Data Processing System is a general purpose, stored program, digital processor employing
solid-state electronic circuitry. Highly flexible RCA 301 Systems are integrated from a diversified array of input/
output devices, a range of memory sizes, and other special features. Each System is tailored to meet the data
processing requirements of a specific organization. While each RCA 301 System is complete within itself, a high
degree of compatibility has been attained with the medium-scale RCA 501, the medium-scale RCA Realcom 3301,
and the large-scale RCA 601.
System efficiency is e nhanced by:
• Rapid memory access time
• Character addressability providing completely variable data organization
• Decimally addressed memory
• Built-in and programmed accuracy controls
• Machine code covering full range of numerics, alphabetics, and special symbols
• Automatic and programmed storage in High-Speed Memory of the contents of various Program Control
Registers
• Direct and Indirect Addressing
• A powerful programming instruction repertoire including the following:
• A Translate by Table instruction permitting efficient internal processing of various code structures
• Locate Symbol instructions permitting an internal search within High-Speed Memory for any character
designated
• Transfer instructions permitting transfer of data to left or right within High-Speed Memory
• Arithmetic instructions permitting Logical "OR", Logical "AND" and Exclusive "OR"
• A Repeat instruction permitting the next repeatable instruction to be repeated a specified number of times
• Automatic programming aids include RCA 301 COBOL, Assembly System, FORTRAN, and a Scientific
Interpreter. An extensive library of service and maintenance routines is also available.
The System processes information prepared by a variety of input media for distribution to the appropriate out­
put. The complete compatibility of System elements provides for ease of expansion at a later date, which is part
of the System philosophy.
SYSTEM ELEMENTS DESCRIPTION
The RCA 301 Computer comprises a Processor and appropriate Input/Output Control Modules. The latter
operate the peripheral devices connected in the system. The Processor is a general purpose, stored program, digital
machine which includes the following sub-units: High-Speed Memory, Program Control, Console Panel, and Power
Supply. The Simultaneous Mode Control may be included in the system to provide concurrent operation of two
input/output devices, or an input/output instruction with a compute instruction.
The High-Speed Memory is a random access, magnetic core device which provides storage and work area for
programs and data. The memory capacity is 10,000 (Model 303), 20,000 (Models 304 and 354), or 40,000 (Models
305 and 355) alphanumeric characters. Each location is decimally addressable and can store one of the RCA 301
characters. The RCA 301 code includes all the letters of the alphabet, the ten decimal digits, and control and special
symbols. (Refer to 301 Code Chart, Appendix A.) The memory cycle time to address, bring into register, and regenerate
a diad in its original memory location is 7 microseconds.
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