Computer Collection Library

The IBM 709x Series

A family of generally compatible first and second generation scientific computers. The 704 was the beginning of the line, supplying the base 36-bit instruction set including single-precision floating point arithmetic. The 709 added data channels and new instructions, but the 7090, with a nearly identical architecture to the 709, was really the center of the line. The principal operating system, IBSYS, was developed to run on the 7090. Three 709 systems were upgraded to be able to run IBSYS, while the later machines were all compatible enough to run it without modification. The 7094 and 7094 II added double-precision floating point. The 7040 and 7044 were later, less expensive machines using the cabinetry and high-speed peripherals of the 1400 series. Because the peripherals of the earlier machines were so slow, it was common to have a set of the off-line peripherals of the 705 or to have a 1401 system to read and punch cards and print listings from tape to avoid wasting valuable machine time. A later option was to "direct couple" a 7094 and 7040 or 7044, so that the 7040 could do the I/O and the 7094 the number crunching.


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