The MCM/70 Computer

Dublin Core

Title

The MCM/70 Computer

Subject

computer hardware: personal 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/70 was designed in the period between 1972 and 73. From the hardware and software engineering point of view it didn't have much in common with early hobby computers, such as the iconic MITS Altair 8800 or Apple I, except that all these computers were microprocessor based. By the time the Altair 8800 kit was offered to hobbyists in the early 1975, with its minuscule 256 bytes of RAM memory and without any high-level programming language to program it, the MCM microcomputers were providing software support for practical applications ranging from engineering design, modeling and simulation to investment analysis and education. By the time the Apple 1 board was offered for sale in 1976 by Steve Jobs and Steve Wozniak—co-founders of Apple Computers—the MCM machines were utilized by Chevron Oil Research Company, Firestone, Toronto Hospital for Sick Children, Mutual Life Insurance Company of New York, Ontario Hydro-Electric Power Commission, NASA Goddard Space Flight Centre, and U.S. Army, just to name some of the installations of the MCM hardware in North America.

The official announcement of the MCM/70 came on September 25, 1973, in Toronto. The computer was unveiled in New York on September 27th and, the following day, in Boston. One of its early prototypes was demonstrated in May of 1973 during the Fifth International APL Users' Conference in Toronto. The company maintained that the MCM/70 was "of a size, price and ease-of-use as to bring personal computer ownership to business, education, and scientific users previously unserved by the computer industry.''

The manufacturing of the MCM/70 started in mid 1974. The computer used the Intel 8008 microprocessor as the CPU and featured both resident and virtual memory. The computer was equipped with built-in plasma display, APL keyboard, and up to two cassette drives. The cassettes were used for storage and retrieval of data and applications software, as well as for the implementation of virtual memory which provided the user with up to 200 Kbytes of memory. The computer's ROM contained an operating system and an APL interpreter. In 1974 and 1975, the computer could be purchased for between $4,700 and $9,800 depending on the hardware configuration. Three models of the MCM/70 were offered: 702 (2KB of RAM and no cassette drives), 704 (4KB of RAM and a single cassette drive), and 708 (8KB of RAM and two cassette drives).

The MCM/70 hardware specification:
  • CPU - Intel 8008, 8-bit,
  • RAM - 2-8KB,
  • ROM - 14-32KB,
  • external storage - up to two cassette drives (100KB each), one to implement the MCM/70's virtual memory,
  • display - Boroughs SelfScan plasma display (1 line 85 characters),
  • peripherals: printer/plotter (e.g. the MCM MCP-132), punch card reader, communications subsystem,
  • ports - Omniport interface with the computer's communication bus,
  • power supply - switching, with power-fail protection, internal batteries.

Software:
  • operating system - EASY (External Allocation System) and AVS (A Virtual System) in ROM,
  • MCM/APL - APL interpreter in ROM,
  • MCM/70 LIB/70 - applications libraries containing APL codes for games as well as for computer aided instructions, finance, statistics, mathematics, and engineering applications (packaged software),
  • TEXT/700 word processor.

The museum has an MCM/70 model 708 as well as two of its prototypes and an MCP-132 printer/plotter.

Further readings:
  1. Stachniak, Z. Learning from Prototypes, IEEE Annals of the History of Computing, vol. 42, no. 2 (2020), pp. 63-71.
  2. Stachniak, Z. Software Recovery and Beyond: The MCM/70 Case, IEEE Annals of the History of Computing, vol. 41, nr. 4 (2019), pp. 110-118.
  3. Stachniak, Z. MCM on Personal Software, IEEE Annals of the History of Computing, vol. 39, no. 1 (2017), pp. 29--51.
  4. Stachniak, Z. Inventing the PC: the MCM/70 Story, McGill-Queen's University Press, 2011.
  5. Stachniak, Z. The Making of the MCM/70 Microcomputer, IEEE Annals of the History of Computing, vol. 25, nr. 2, (2003), pp. 62--75.
  6. Stachniak, Z. The MCM/70 Computer, CORE, the Computer History Museum (Fall 2003).

Creator

Micro Computer Machines

Date

1973-1975

Relation

Micro Computer Machines collection

Coverage

world, 1970s

Files

MCM70.jpg
MCM70_emulator.png

Citation

Micro Computer Machines, “The MCM/70 Computer,” York University Computer Museum Canada, accessed March 29, 2024, https://museum.eecs.yorku.ca/items/show/293.

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