Honeywell 800


The Datamatic Division of Honeywell announced the H-800 electronic computer in 1958. The first installation occurred in 1960. A total of 89 units were delivered. The H-800 design was part of a family of 48-bit word, three-address instruction format computers that descended from the DATAmatic 1000, which was a joint Honeywell and Raytheon project started in 1955. The 1800 and 1800-II were follow-on designs to the H-800.

Data

The basic unit of data was a word of 48 bits. This could be divided in several ways:
  • 8 alphanumeric characters of 6 bits each
  • 12 hexadecimal or decimal characters of 4 bits each
  • 16 octal characters of 3 bits each
  • An instruction with four components of 12 bits each: the operation to be performed, and three memory addresses.

Hardware

The Honeywell 800 was a transistorized computer with magnetic-core memory. Its processor used around 6000 discrete transistors and around 30,000 solid-state diodes.
The basic system had:
  • A Central Processor with 16 controlled input/output trunks
  • An Input/Output Control Center with control functions for:
  • * A card reader/punch,
  • * A high-speed printer
  • * Up to four magnetic-tape units
  • A control memory of 256 special registers of 16 bits each
  • A main memory containing four banks of 2048 words.
Extra peripherals could be added running through additional controllers with a theoretical possibility of 56 tape units.
Up to 12 more main memory banks could be added.
A random-access disc system with a capacity of 800 million alphanumeric characters could be added.
Multiprogram control allowed up to eight programs to be sharing the machine, each with its own set of 32 special registers.
A Floating-Point Unit was optionally available. The 48-bit word allowed a seven-bit exponent and 40-bit mantissa. So numbers between 10−78 and 10+76 were possible and precision was 12 decimal places. If the floating point unit was not installed, the floating-point commands were implemented by software simulation.
Peripheral devices included: high-density magnetic tapes, high-speed line printers, fast card and paper tape readers and punches to high-capacity random access magnetic disc memories, optical scanners, self-correcting orthoscanners and data communications devices.

Software

Available software included: