The MCM/70 Personal Computer


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 and, later, manufactured the first microprocessor-based computer designed specifically for personal use the first PC.

This exhibit highlights and celebrates the pioneering work on personal computing at MCM and is dedicated to the makers of the MCM/70 computer.

Welcome to the Computer Age!

MCM's first computerthe MCM/70was 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 Wozniakco-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 photograph taken during the announcement of the MCM/70 in Toronto on 25 September 1973 in Royal York Hotel.

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 un-served by the computer industry.''

With the unavailing of its computer, MCM introduced a new personal perspective to the desktop information processing narrative and correctly assessed the potential of microprocessor technology as the computing paradigm shifter. These were 
inexpensive, easy-to-operate computers, such as the MCM/70, and not programmable calculators, that were to make widespread, personal information processing a reality. In 1973, Mers Kutt, the inventor of the MCM/70 and the company's first president, painted computing's future landscape as one filled with millions of small computers, just like the MCM/70, and only a limited number of large ones.

With the MCM/70 personal computer concept, MCM hoped to create a lucrative niche on the electronics market between inexpensive, easy to use but inadequate for many data processing tasks desktop electronic calculators, and large, expensive, and complex to operate general-purpose computers. The MCM/70 was to appeal to both computer experts and novices alike. An MCM/70 owner was expected to be able to install his or her computer without any need for assistance from MCM’s Customer Service Department. MCM would supply a turnkey system, some software, and a user manual that explained, in simple 
language, the principles of the computer's operation and programming in the APL language that was offered with the computer. Instead of the traditional systems engineering and programming support provided to mainframe computer users, there was MCM’s encouraging message, “Good luck, and welcome to the computer age!”

MCM's personal computer concept attracted considerable international attention in 1973 and swiftly elevated MCM to the position of one of the most innovative high technology companies. "There seems little doubt that Canada has stolen an early world lead in the new era of ‘distributed processing’ which will bring the dream of a computer in every home and office closer to reality.” wrote Electronics Communicator following the MCM/70’s announcement in Toronto.

Prototyping the Future

MCM built several prototypes of the MCM/70 before the computer's manufacturing began in mid-1974. All of them have their roots in the Key-Cassette concept developed by the company's co-founder and first president Mers Kutt. A drawing of it can be found in design notes that Kutt kept from late 1971 until mid 1974. 


The Key-Cassette concept. Drawing by Mers Kutt, 1972.

The one-page sketch depicts a portable computing device with built-in keyboard, one-line display, cassette storage, and acoustic coupler for communication over phone lines. In addition, the device was to be programmed in the APL language. The Key-Cassette concept already expressed several key aspects of personal computing philosophy that MCM would be shaping in the coming years: that of an individual-focused complete computing environment, easy to learn and interact with. 


This prototype was demonstrated during the Fith International APL Users' Conference in Toronto, 1973.


José Laraya in front of an MCM/70 and one of its prototypes. York University, 2011.

From the early stages of the MCM/70 design process, MCM used the computer's prototypes as demonstrators. MCM built the first such demonstrator in early 1973, in time for the computer’s public presentation in May during the Fifth International APL Users' Conference in Toronto. The unveiling of the MCM computer at the conference was a landmark event in the history of personal computing because it showed for the first time that a practical, portable, general-purpose computer designed for personal use and programmed in a high-level language could be economically manufactured.

In the summer of 1973, several MCM/70 demonstrators were on their European and North American promotional tours. One of them was what can be now considered the first portable and battery operated PC. It was assembled in record short time for a demonstration at the APL Congress that was to take place in August at the Technical University of Denmark in Lyngby, Denmark. In July 1973, MCM decided to pack the current MCM/70 hardware, including a keyboard, a one-line plasma display, and a single cassette drive, into an attaché case and to operate all of it on batteries exclusively. The company expected considerable marketing gains from the planned ground-breaking presentation of a never-seen-before luggable, battery operated, general-purpose computer which they named the Executive.

The project was successful. On August 23, the day after the Executive’s demonstration at the congress, the Danish daily Politiken published a front-page article about a sensational computer from Canada. The article included two photographs depicting MCM employee Ted Edwards operating the Executive on the doorstep of the auditorium where the conference took place.

For a moment, MCM contemplated the manufacturing of the Executive and made an appropriate announcements in press. In October 1973,the computer was shown during the National Computer Show and Conference in Toronto. But, in the end, the company quietly abandoned the Executive concept focusing its attention on the development of the desk top version of the MCM/70.


Ted Edwards demonstrating the Executive at the Technical University of Denmark during the

APL Congress in Denmark, August 1973 (© Politiken).

The Production Model

The manufacturing of the MCM/70 started in the mid 1974 but the production was limited. 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 (OS) 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. The base machine without external storage and minimal memory (of just 2Kbytes of user workspace) was sold in North America and Europe as an advanced programmable calculator.


The MCM/70 production model, 1974.

The MCM/70's OS comprised two modules, called EASY and AVS, that managed the computer's virtual memory, cassette drives, and power supply. It also provided general I/O utilities. The user interacted with the computer through a set of simple OS commands. EASY (or External Allocation System) provided traditional I/O functions for digital cassette-based storage. It also controlled the mounting and unmounting of cassette tapes and the "graceful" powering down of the computer with an OS command. 
A Virtual System (AVS) managed virtual memory of the computer.

The MCM/70's virtual memory, developed by André Arpin between 1973 and 1974, was a unique piece of computer engineering. In the early 1970s, this type of memory was available only on some mainframes, and there were no blueprints for its implementation on a small computer.% Andre image

The choice of a programming language was as important to the MCM/70 personal computer concept as the machine's OS. For MCM, that special language was APL created by Kenneth Iverson and implemented by Gord Ramer for the MCM/70. At the time of the computer's design, APL was considered powerful, concise, and easy to learn and use. It was offered by several major computer manufacturers and time-sharing systems.

Users as Programmers and Software Consumers

At the time of the MCM/70's introduction to the market, MCM viewed the end-users of its computers as programmers responsible for their own applications software needs. However, by the end of 1975, MCM views on end-users began to change and the company assumed some responsibilities for the development of systems and applications software to address the needs of "software consumers"  an emerging new class of MCM clients. To that end, MCM offered its clients word processors and some finance programs. It created communications hardware and software to remotely connect MCM computers to several APL time-sharing systems, to IBM 360 mainframes, and to other MCM machines.

The Next Generation of MCM Computers

Already in early 1974, MCM was researching possible directions for the development of new generation of computers to replace the slow MCM/70 and maintain a safe technological distance from competition. In 1975, the company released the MCM/700  an upgraded version of the MCM/70, and the model /800 in the following year. The company made also available a line of peripherals and displays. The MCM/800 was followed by a successful model /900 unveiled in 1978. The last two computers manufactured by MCM were the Power and MicroPower which the company started to sell in 1980.

Impact and Historical Significance

It is difficult to explain unequivocally why the MCM/70 was not a commercial breakthrough that launched the personal computing industry. It is also difficult to estimate the number of the MCM computers sold world wide although it is known that the MCM/70 computers sold well France and even found their way onto the desks in the Soviet Academy of Sciences.


Mers Kutt and Gordon Ramer  the co-founders of Micro Computer Machines, 1973.

Even so, it was MCM's historical role to show that with the advent of the microprocessor technology, affordable personal computing was at our fingertips, that it was not too farfetched to imagine a computer on a desk in a school, an office or at home.

Further Readings:

  • Stachniak, Z. Inventing the PC: The MCM/70 Story, McGill-Queen's University Press, 2011.
  • Stachniak, Z. MCM on Personal Software, IEEE Annals of the History of Computing, vol. 39, no. 1 (2017), pp. 29--51.

The MCM/70 Personal Computer