MCM/800

Dublin Core

Title

MCM/800

Subject

computer hardware: computer

Description

Historical context (by Z. Stachniak)
In April, 1972, Intel Corp. of Santa Clara, California, announced its first 8-bit microprocessor — the 8008. In just a few months, the prototypes of the first general purpose computers powered by the 8008 chip were already working on site at the French company Réalisations et Études Électroniques located in the suburbs of Paris and at Micro Computer Machines (MCM) with headquarters situated on the outskirts of Toronto. These firms fully recognized, articulated, and acted upon the immense potential of the budding microprocessor technology for the development of a new generation of cost effective computing systems. However, it was MCM which built the first microprocessor-based computer designed specifically for personal use — the MCM/70, the first PC.

The MCM/800 was MCM's second generation computer. As was the case with the MCM/70, the /800's hardware was designed by Jose Laraya's team while Gord Ramer was the chief software engineer. From hardware and software point of view, the computer was similar to the MCM/70 PC. The /800  functioned under similar AVS/EASY operating system and had MCM/APL interpreter built-in. However, there were also significant differences. The new computer was not portable and was not powered by a single-chip microprocessor. Instead, the computer's CPU was implemented using bitslice technology with discrete components. While this design choice allowed to execute the same instruction set as the MCM/70's 8008 microprocessor at much higher speed, this technological switch marked MCM's departure from the microprocessor direction trailblazed by the company in the early 1970s.

The computer was announced in July 1976 as "the combination of data processing and word processing for as little as $400 a month." It was targeted at problem solving and small business markets. In 1976, the computer was sold for between $8,400 (4KB ROM configuration) and $10,800 (16KB ROM configuration).

The MCM/800 hardware specification:
  • CPU - bitslice technology using AM25LS181 4-bit arithmetic logic circuits,
  • RAM - 8KB expandable to 16KB,
  • ROM - 32KB, expandable,
  • external storage - a built-in single cassette drive (100KB storage capacity), SDS-250 single and DDS-500 dual diskette systems (256KB per disk storage capacity),
  • display - Boroughs SelfScan plasma display built-in (1 line 85 characters), VDU-9620 external CRT display terminal,
  • keyboard - IBM 2741-style, APL keys, built-in,
  • communications subsystem - built in (optional),
  • peripherals: SDS-250 single and DDS-500 dual diskette systems, MCM MCP-132 printer/plotter, PMR-400 punch card reader,
  • VDU-9620 CRT display terminal, SCI-1200 Communications Subsystem (which provided the same facilities as the built-in option),
  • ports - Omniport IO interface (8-bit, parallel), RS-232C serial port,
  • power supply - with power-fail protection.

Software:
  • operating system - EASY (External Allocation System) and AVS (A Virtual System) in ROM,
  • MCM/APL - APL interpreter in ROM,
  • MCM applications libraries -- contained APL codes for games as well as for computer aided instructions, finance, statistics, mathematics, and engineering applications (packaged software),
  • PVAS -- Pension Actuarial Valuations and Pension Plan Administration
  • TEXT/800 word processor.
Museum holdings:
  • MCM/800 model 808, serial number...
  • MCM/800 model 816, serial number 611259,
  • MCP-132 printer/plotter,
  • DDS-1000 and MPD-1000 diskette systems.
Recommended readings:

Creator

Micro Computer Machines

Date

1976

Coverage

North America, 1976-1979

Files

mcm800.png
MCM800Catalog.png
mcm800_bw.jpg

Citation

Micro Computer Machines, “MCM/800,” York University Computer Museum Canada, accessed October 14, 2024, https://museum.eecs.yorku.ca/items/show/282.

Output Formats