General Electric




Le GE-200 couvre une famille d'ordinateurs de moyenne  puissance dveloppe dans le GE Computer Department. The GE-400 series is a family of medium large computers developed in the Phoenix GE Computer Department 

The GE-200 product originated in the early days of the Computer Department in Phoenix AZ.

In fact, the GE-200 name has been also used for banking products derived from the first GE computer, the ERMA project, General Electric marketed in the early 60s the GE200 Bank Transit system around a document (check) sorting system.

Three variations of the same central processor constitutes that product line sold between 1959 and 1966.

  • GE-225
  • GE 235
  • GE-215

The GE-225 was derived from the GE-312 and 412 Process control computers, then part of the Computer Department products. It was designed by Arnold Spielberg and Chuck Prosper, ex-RCA engineers who have been working on BIZMAC. It was introduced in 1960.


The GE-225 was a 20-bits word binary machine with 3 hardware registers. It was not specially designed for business applications.
The instruction of 20-bits contains a 5-bits OP code, 2-bits of address modification and 13-bits of operand address 

Optional features were:

  • Floating Point .
  •  Decimal arithmetic (with 3 x6-bits BCD numbers per word ,
  • Real-Time clock, 
  • Move command

    Addition was performed in 36 s. Multiplication in 288 s and Division in 495s

Technology was solid-state (diodes and transistors). A 8K words system contained 1,000 circuit boards, 10,000 transistors, 20,000 diodes and 186,000 magnetic cores. The power dissipation was 16 KVA.

Main memory was offered in 4, 8 and 16K words.Its access time was 18 s.

Peripherals included:

  •     Disks (MRADS Mass Random Access Data Storage) 98304 words per unit, thruput 62.5Kcps, up to 32 units.
  •     Magnetic Tapes at 200 and 556 bpi operating at 75ips
  •     Card reader 400 or 1000 cpm
  •     Card punch 100 or 300 cpm
  •     Paper Tape reader at 250 or 1000 cps
  •     Paper Tape punch 110 cps
  •     Line Printer  900 lpm 160 columns
  •     Datanet 15 single communication line controller 75 to 1600 bps
  •     Datanet 30 communications processor
  •     Check sorter 1200 dpm
  •     Typewriter 10 cps

Up to 11 devices may operate simultaneously, through independent channels connected to the memory by an autonomous "controller selector". Unit record devices operated under processor control.

Software included

  • a compiler of GECOM  language (a COBOL dialect with many ALGOL features),
  • TABSOL (a language based on decision tables),
  • WIZ (an Algebraic compiler),
  • GAP a translator for IBM 650 and LGP30
  • a Report Generator.
  • IDS data base system, developed by Charlie Bachmann for the GE-225 before it was ported to GE-400 and GE-600

 One of the major initial customers was at Huntsville Arsenal, a NASA predecessor.

The GE-215 was a scaled-down version of the GE-225. The number of channels was reduced to 6.The main core memory was limited to 4K and  8K words.

Addition was performed in 72 s. Multiplication in 342 s and Division in 531 s

The GE-235 was a re-implementation (three times faster) of the GE-225 with a faster memory (cycle 5 s) designed in 1962 and delivered in 1964.

Addition was performed in 12 s. Multiplication in 84 s and Division in 85 s, thanks to a new high-speed arithmetic unit. 
More I/O operations can operate simultaneously through a second access controller


The GE-265 that was the system running the first commercial time-sharing system is the association of a GE-235 processor and of a Datanet-30 communication processor.
The software was designed at Dartmouth College as DTSS in 1963-1964. While BASIC was the main programming language created for that system, it was also used in ALGOL and Fortran. A peculiarity of the DTSS was that the main part of the operating system was resident inside the DN-30 front-end processor and that only the user programs and their environment (e.g.the BASIC interpreter) were executed by the GE-235. The two processors were interconnected through a direct interface and were sharing a disc unit DS-20.

This time-sharing system was introduced as a service by GE and by Bull-General Electric in 1965

a Teletype 33 DTSS terminal at Bull-GE in 1966

The GE-265 operating system was renamed Mark I and was later (1968) ported on GE-635 as Mark II and Mark III, by General Electric Information Services Division (GEISD) that was not transferred to Honeywell in 1970 and remained in General Electric.


Note: The ERMA machine developed for the Bank of America and jointly by General Electric and NCR  (as NCR 304) has got also the name of GE-210 when sold to other banks than BoA, and GE-304B when used internally at General Electric . It  is not part of "Compatibles GE-200."

Revision: 21 nov. 2005



King of Seven Dwarves, book by Omer Oldfield IEEE Computer Society Press ISBN 0-8186-7383-4

A contemporary (1964) description of the DTSS system. reproduction of a GE document