The Datamatic Division of Honeywell announced the H-800 electronic computer in 1958. The first installation occurred in 1960. A total of 89 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.[1]


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.


The Honeywell 800 was a transistorized computer with core memory. Its processor used around 6000 discrete transistors and around 30,000 solid-state diodes.[2] The basic system had:

  • A Central Processor with 16 controlled input/output trunks
  • An Input/Output Control Center (IOCC) with control functions for:
    • A card reader/punch,
    • A high-speed printer
    • Up to 4 magnetic tape units
  • A Control Memory of 256 special registers of 16 bits each
  • A Main memory containing 4 banks of 2048 words.[3]

Extra peripherals could be added running through additional controllers with a theoretical possibility of 56 tape units.[3]

Up to 12 more main memory banks could be added.[3]

A random access disc system with a capacity of 800 million alphanumeric characters could be added.[3]

Multiprogram control allowed up to 8 programs to be sharing the machine, each with its own set of 32 special registers.[3]

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.[3] If the customer did not buy the floating point unit, then 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.[3]


Available software included:

  • ARGUS (Automatic Routine Generating and Updating System), an assembly language.
  • FACT (Fully Automatic Compiling Technique), a business compiler.
  • PERT (Program Evaluation and Review Technique), a project management system.
  • COP (Computer Optimization Package), a program testing system.
  • COBOL (COmmon Business Oriented Language), a compiler for the well known business programming language.[3]
  • FORTRAN (FORmula TRANslator), a compiler, runtime package, and "load and go" OS for the scientific language compiler.


  1. ^ Mark Smotherman Paper about the Honeywell 800
  2. ^ Eldon C. Hall, Journey to the Moon: The History of the Apollo Guidance Computer,AIAA, 1996, ISBN 156347185X, page 32
  3. ^ a b c d e f g h Company Sales Manual for the Honeywell 1800

Further readingEdit

Jane King, William A. Shelly, "A Family History of Honeywell's Large-Scale Computer Systems," IEEE Annals of the History of Computing, vol. 19, no. 4, pp. 42–46, Oct.-Dec. 1997, doi:10.1109/85.627898

External linksEdit