IBM 702
Encyclopedia
UNIVAC I
The UNIVAC I was the first commercial computer produced in the United States. It was designed principally by J. Presper Eckert and John Mauchly, the inventors of the ENIAC...
—the first mainframe computer using magnetic tape
Magnetic tape
Magnetic tape is a medium for magnetic recording, made of a thin magnetizable coating on a long, narrow strip of plastic. It was developed in Germany, based on magnetic wire recording. Devices that record and play back audio and video using magnetic tape are tape recorders and video tape recorders...
s. Because these machines had less computational power than the IBM 701
IBM 701
The IBM 701, known as the Defense Calculator while in development, was announced to the public on April 29, 1952, and was IBM’s first commercial scientific computer...
and ERA 1103, which were favored for scientific computing, the 702 was aimed at business computing.
The system used electrostatic storage, consisting of 14, 28, 42, 56, or 70 Williams tube
Williams tube
The Williams tube or the Williams-Kilburn tube , developed in about 1946 or 1947, was a cathode ray tube used to electronically store binary data....
s with a capacity of 1000 bit
Bit
A bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...
s each for the main memory, giving a memory of 2,000 to 10,000 character
Character (computing)
In computer and machine-based telecommunications terminology, a character is a unit of information that roughly corresponds to a grapheme, grapheme-like unit, or symbol, such as in an alphabet or syllabary in the written form of a natural language....
s of 7 bits each (in increments of 2,000 characters), and 14 Williams tubes with a capacity of 512 bits each for the two 512 character accumulators.
A complete system included the following units:
- IBM 702 Central Processing Unit
- IBM 712 Card Reader
- IBM 756 Card Reader Control Unit
- IBM 717 Printer
- IBM 757 Printer Control Unit
- IBM 722 Card Punch
- IBM 758 Card Punch Control Unit
- IBM 727IBM 727The IBM 727 Magnetic Tape Unit was announced for the IBM 701 and IBM 702 on September 25, 1953. It became IBM's standard tape drive for their early vacuum tube era computer systems. Later vacuum tube machines and first-generation transistor computers used the IBM 729-series tape drive...
Magnetic Tape Unit - IBM 752 Tape Control Unit
- IBM 732 Magnetic Drum Storage Unit
The 702 was announced September 25, 1953 and withdrawn October 1, 1954, but the first production model was not installed until July 1955. The successor to the 702 in the 700/7000 series was the IBM 705, which marked the transition to magnetic core memory
Magnetic core memory
Magnetic-core memory was the predominant form of random-access computer memory for 20 years . It uses tiny magnetic toroids , the cores, through which wires are threaded to write and read information. Each core represents one bit of information...
.