IBM 702
The IBM 702 was IBM's response to the UNIVAC—the first mainframe computer using magnetic tapes. Because these machines had less computational power than the IBM 701 and ERA 1103, which were favored for scientific computing, the 702 was aimed at business computing. 

The 702 was announced September 25, 1953, and withdrawn October 1, 1954, but the first production model was not installed until July 1955.

History
Fourteen 702s were built. The first one was used at IBM. Due to problems with the Williams tubes, the decision was made to switch to magnetic-core memory instead. The fourteenth 702 was built using magnetic-core memory, and the others were retrofitted with magnetic-core memory.

The successor to the 702 in the 700/7000 series was the IBM 705, which marked the transition to magnetic-core memory.

Overview
The 702 was designed for business data processing. Therefore the memory of the computer was oriented toward storing characters. The system used electrostatic storage, consisting of 14, 28, 42, 56, or 70 Williams tubes with a capacity of 1000 bits each for the main memory, giving a memory of 2,000 to 10,000 characters of seven 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 727 Magnetic Tape Unit 
IBM 752 Tape Control Unit 
IBM 732 Magnetic Drum Storage Unit

Total weight (depending on configuration): about .

See also
 List of vacuum tube computers

References

External links
IBM Archives: 702 Data Processing System
IBM 702 Documents on bitsavers
The Williams Tube
IBM 702 photos

702
7 0702
Computer-related introductions in 1953
Variable word length computers