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This page continues the documentation of the computers at Carnegie-Mellon University  in the 1960's. You can click on the links above to learn about some of the other computers.

Unisys History Newsletter

Volume 3, Number 4
August 1999

Sperry Rand Military Computers 1957-1975

by George Gray

Although many of the computers of the 1940s were developed as military projects, the use of vacuum tubes made them too big and unreliable for incorporation into actual weapons systems. The Eckert-Mauchly Computer Corporation built the BINAC in 1949 for Northrop Aircraft, but no one seriously expected it to be put into an airplane. The massive SAGE (semi-automatic ground environment) system built by IBM during the 1950s for the North American air defense system was for command and control, not for missile guidance. When vacuum tubes were replaced by transistors, it became possible to have computers of smaller size and greater reliability. The transistor was invented at Bell Laboratories in 1948, but it took several years of development to become suitable for use in computers. Bell Labs built the first transistor computer, the TRADIC (Transistor Digital Computer), for the Air Force in 1954. It used 700 point-contact transistors and 10,000 germanium diodes. (A diode is an electronic device which allows current to flow in only one direction.) Both of the two major computer development groups (St. Paul and Philadelphia) at Sperry Rand became involved in early transistor computer projects. Philadelphia became embroiled in the long and costly LARC supercomputer project for the Atomic Energy Commission. St. Paul, building on its early work for the Navy, became heavily involved in military projects.


St. Paul's original customers, the nation's cryptologists at the National Security Agency, wanted machines more powerful and versatile than the Atlas I (UNIVAC 1101) and II (UNIVAC 1103) to process text and look for patterns, a task which they called data editing. This led to a secret project for the Bogart computer, a code name which supposedly referred to a then famous newspaper editor, John B. Bogart. At other times the computer was referred to as the X308. Once the computer was completed the secrecy was not so great as to preclude a presentation on it at a 1957 Association for Computing Machinery conference in Los Angeles. The design team was led by Seymour Cray. The processor logic circuits did not use transistors, but a combination of diodes and magnetic cores, so it can be viewed as a further development of the MAGTEC. The instruction word was made up of a six-bit operation code, a three-bit field to indicate the use of index registers, and a 15-bit memory address. The memory address was in turn composed of a 12-bit address followed by three bits which gave the capability of addressing any of the three 8-bit characters in the word (partial-word addressing). There were three arithmetic registers and seven index registers. The Bogart had 4096 words of 24-bit core memory, the maximum which could be addressed in 12 bits. The memory system was designed by Cray and Sidney Rubens of St. Paul in conjunction with Jacob Randmer of Norwalk and was manufactured at Norwalk. The Bogart's central processing unit weighed 3000 pounds and occupied 22 square feet of floor space, a considerable reduction in size and weight from comparable vacuum tube machines. The prototype Bogart was completed in September 1956 and tested for ten months. The four production models of the Bogart were delivered between July 1957 and January 1958. Later the NSA wanted another one, so the prototype model was given some finishing touches and delivered in December 1959. It was used in ROB ROY, an early NSA test of the remote job entry (RJE) concept. After he left Sperry Rand in late 1957, Cray used much of the logic design from the Bogart in his first computer at Control Data Corporation, the 1604, which was completed in January 1960.

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Pat Stakem wrote:
"My understanding was that the Dept. Head (and I can't remember his name, preceded Jordan) had this thing for surplus stuff, and that's why we had the Bogart, the Athena, the big lathe that broke the granite steps, etc.

This was core memory unit that I, Mark DiVecchio, tried to add to the Athena. It was my senior project. It never worked. The core, IIRC, was from the Bogart. Photo taken about 1971. I am somewhat amazed that this project sat, virtually untouched, from spring of 1970 until I took this photo and it probably remained untouched until Glenn Sembroski diassembled the Athena to ship to the Smithsonian.

From the Bogart Programmers Manual:

1. Core Storage
× This storage can retain 4096 24-bit words, a total of 98,304 bits of information
× The Magnetic-core storage contains 24 planes. Each 10 inch plane is a 64 by 64 square array of 406 cores. Three of the four wires running through each core write information into the core and the fourth wire senses whether a 1 or a 0 is stored in the core.
× If the core is magnetized in one direction, a 1 is stored in it; and if it is magnetized in the reverse direction, a 0 is stored in it. Information read out by applying a current to the two read-out wires drives the core into its zero state. If a 1 is stored in the core, the magnetic direction-change induces a voltage in the read-out wire. By sensing the voltage on the read-out wire, it is possible to determine the previous magnetic state of the core.
× Since the read-out wire sets the core to the zero state, it is necessary for the memory circuits to restore the core to a one-state. If it contains a 1, this is the regeneration portion of the storage cycle. The total storage cycle of read-out and information regeneration takes 20 microseconds per word.


Photo from the   Bogart Programmers Manual. The computer was supposedly named after John B. Bogart, city editor of The (New York) Sun. This was a reference to the Bogart's primary function - "data editing", what is now called data mining.
When a dog bites a man, that is not news, because it happens so often. But if a man bites a dog, that is news.
John B. Bogart
(1848 - 1921)


Bogart Programmers Manual  (7+ MB)

Bogart Information

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