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Burroughs 205

Manufacturer Burroughs
Designed by ElectroData, Burroughs bought ElectroData in 1956
Identification,ID 205
Date of first manufacture 1956, 1954
Number produced -
Estimated price or cost-
location in museum -
donor -

Contents of this page:

Electrodata 205

Electrodata Computer, 1957
(Burroughs Corporation)

This vacuum tube machine sold for $135,000. It was widely used for purposes ranging from research at NASA Ames to record management at General Insurance. The machine required 16 people to run around the clock.

From the collection of The Computer Museum, X1055.91

From Burroughs 205 Central Computer Handbook
  • Words of 10 decimal digits plus a sign indicator, Each decimal digit is 4 bits. Alpha characters are 2 decimal digits each. Decimal point is just left of sign.
  • A 3570 RPM magnetic drum of 4,000 words main storage, stored in 20 bands of 200 words each. addressed as 0000 through 3999.
  • plus four "quick access" bands of 20 words each. (Recirculating drum registers 1/10 th the drum circumferance.) Access is 10 times faster than main drum. Addressed 4000 through 7999. Word 4000 is the same as word 4020, 4040, ...
    Block moves can move instructions or data into any of these four quick access tracks.
  • Three "electronic" registers
    A Register holds 11 digit word, Holds results of all arithmetic operations.
    R Register holds 10 digit word. Affected by multiple and divide instructions.
    B Register holds 4 decimal digits (0000-9999)
    - which can be added to address digits [an index "register"]
    - added if first digit of control digits in instruction is 1
    D Register holds 11 digit word. A data transfer register, not programmable.
    C Register holds instruction being executed
  • Instruction format
    - low order 4 digits - address
    - next two digits - order [operation]
    - next four digits - control digits - variations in execution of instruction
    - sign digit - ?add B register to operand address?

Special features
From Burroughs 205 Central Computer Handbook
  • Overflow condition halts machine unless following instruction is a conditional jump
  • Forbidden combination of bits (non-decimal) in a register halts machine
  • Burroughs 205 Command List
  • Input/output units: punched cards, punched tape, magnetic tape, keyboard
1600 vacuum tubes

IT - Internal Translator. A.J. Perlis et al, Carnegie Tech ca 1957. Early compiler for math originally for Burroughs 205, then IBM 650. Forerunner of RUNCIBLE, GATE, CORRELATE and GAT. IT source code was converted to PIT, thence to SPIT. Sammet 1969, pp.139-141. Versions: IT-2 produced machine language directly, IT-3 developed at Carnegie added double-precision floating point. CACM 1(5):22 (1958).

Historical Notes
Copies of a stack of Burroughs-ElectroData manuals from LaFarr Stuart
Document Size MByte

Automating Telemetry Operations says

" ... Dr. Rudolf Bruns's data reduction team pioneered the use of computers in Saturn I launch operations. Digital computers offered two advantages. During a launch the computer could record incoming telemetry data on a magnetic tape and subsequently process compact printouts in a relatively short time. The computer, supported by peripheral equipment such as cathode ray tube consoles, could display critical information in real time.

The Flight Instrumentation Planning and Analysis Group set up a Burroughs 205 computer alongside the telemetry station in hangar D prior to the SA-1 launch. A tarpaper shack housed the computer - a far cry from facilities the team would enjoy in a few years. Despite its primitive surroundings, the 205 provided guidance data and some measurement reduction in real time. A General Electric [GE-225] computer replaced the Burroughs machine on SA-3; the GE computer's solid state circuitry and core memory provided a faster sampling of Saturn telemetry. ..."

A real or look-alike BURROUGHS 205 on Batman & Robin on the TV series?

Competed with the IBM 650.

This Artifact

Interesting Web Sites

Other information
Stories about the B5000 And People Who Were There by Richard Waychoff

from Orest - Oct 15, 2011

The Burroughs 205 appears to be co-starring in "The Angry Red Planet" ( Available on netflix.
comment by Ed Thelen
A frame from the movie as presented on Netflix. Time 56:27 from the beginning. Friends, this movie is a laugher, NOTHING techie is plausable. For instance, this vacuum tube computer is in this spaceous room in the rocket on Mars, complete with several Tektronix scopes and a Simpson meter ;-))

from B.J. Broadbent

I went to work for Electrodata in May of 1956.. and Burroughs bought the company at just about the same time. After attending training classes for about 6 months, I was assigned to maintain the demonstration computer in the front showroom of the factory !!! It was a very interesting job. I got to assist when demonstrations were put on for potential customers, helped when a documentary film crew came in to make a picture (they loved it when I agreed read in a punched paper program tape in without putting the takeup reel on... letting the tape spill onto the floor... they loved the effect). Later I maintained a computer at a wholsale grocery company in Whitier (can't remember the name) and then was sent down to San Diego Navy Electronics Lab to maintain the Datatron 205 there.

We were on the second floor of the lab in a large room with the 205 and several large analog computers. Behind our computer was a door with a small balcony that looked down into a 2-story "warehousing" area. Down in that area the Navy had put a brand new Univac computer that was all transistorized and even had a track-ball mounted in the control conole to control the cursor on a CRT screen (and this was in 1958). That computer was called "The Countess".

We knew that it was female because on cold nights the temperature would go down severely in the area where the Countess was and they would have to throw a blanket over it to kep it warm... yet, we were always having to turn down the thermostat upstairs to keep the 205 cool !!!

I have lots more info about early 205 happenings !!!

From LaFarr Stuart Jan 2011

Hi: In 1957 I was at University of Utah studying Meteorology, thanks to US Air Force. (Meteorology was never my choice.)

More interesting: The University had ordered a Datatron 205, and I attended the training provided by Bob Albright. (Or was it Albrecht, I am not sure of the spelling of the name. He moved the Bay area, and may be a good source of 205 information.) At the time he was out of Burroughs Denver office. All of us got, what I believe is a complete set of 205 manuals. I can't believe I would have thrown them away, but I don't know where they are at.

The 205 was more or less built around paper tape. (The op-code for a paper tape read was 00, so one button which cleared all the registers would start a paper tape read into location 0000, and the program counter would start at 0000.)

I left before the machine was delivered. I have never seen a working 205, and never knew anything about its reliability.

Cheers,, LaFarr
from San Jose

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Updated Juy 1, 2018