IBM 709

The IBM 709 was an early computer system introduced by IBM in August, 1958. It was an improved version of the IBM 704 and the second member of the IBM 700/7000 series of scientific computers.

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The IBM 709 added overlapped input/output, indirect addressing, and decimal instructions.

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The basic instruction format was a 3-bit prefix, 15-bit decrement, 3-bit tag, and 15-bit address. The prefix field specified the class of instruction. The decrement field often contained an immediate operand to modify the results of the operation, or was used to further define the instruction type. The three bits of the tag specified three index registers, the contents of which were subtracted from the address to produce an effective address. The address field either contained an address or an immediate operand.

Computer: A computer is a device or for processing information from data according to a program — a compiled list of instructions. The information to be processed may represent numbers, text, pictures, or sound, amongst many other types....

IBM: :Big Blue redirects here. For the movie, see The Big Blue....

1958: 1958 was a common year starting on Wednesday of the Gregorian calendar....

IBM 709 related Images and Photos (experimental)

Technician Manipulating 1 of Hundreds of Dials on Panel of IBM's Room Size Eniac Computer