IBM System/360 Model 20
The IBM System/360 Model 20 was the smallest member of the IBM System/360 family announced in November, 1964. The Model 20 supported only a subset of the System/360 instruction set, with binary numbers limited to 16 bits and no floating point.[1] In later years it would have been classified as a 16-bit minicomputer rather than a mainframe, but the term "minicomputer" was not current, and in any case IBM wanted to emphasize the compatibility of the Model 20 rather than its differences.
Developed by IBM, Germany, the system was intended for data processing and as a replacement for tab equipment. An incompatible small computer, the IBM 1130 introduced the following year was designed for scientific and engineering computing.
Peripherals
A peripheral unique to the Model 20 was the IBM 2560 MFCM ("Multi-Function Card Machine"). Because of its reliability problems, often involving card jams, the acronym was often interpreted as referring to many less favorable names. Nevertheless the 2560 combined the functions of a card reader, card punch, and card sorter, allowing the Model 20 to replace several separate pieces of punched-card equipment.
References
- ^ IBM Corporation (1964). IBM System/360 Model 20 Functional Characteristics (PDF).