On September 25, 1973, a small electronics company Micro Computer Machines (MCM) of Toronto unveiled its desktop, portable, microprocessor-based computer — the MCM/70. MCM introduced its computer as being of "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.'' In short, MCM unvailed the world's first microprocessor-based PC.
Only a few MCM/70s survived and are now in computer museums and private collections scattered around the world. The age-related physical deterioration of some of the electronic components makes the use of the surviving MCM computers for the purpose of demonstration, experimentation, and research inadvisible.
An alternative approach to the direct use of MCM hardware is to write histrorically accurate software emulators of this computer destined for modern desktop and laptop computers. Although such emulators do not necessarily reflect the computer's hardware on, say, integrated circuit level, they offer a platform for research of general hardware organization, storage organization, systems and applications software, etc.
In 2019, YUCoM offered its emulator of the MCM/70 as free software. The mulator is the result of an extensive study of the MCM/70 hardware and of a software recovery project that has preserved MCM software from approximately 100 digital MCM cassettes donated to the museum. It emulates the original MCM/70 hardware with 8Kbytes of RAM with high historical accuracy. In particular, the memory management as well as tape, keyboard, and display functionality are emulated accurately. The emulator operates under the original systems software and is using the original tape storage organization (reconstructed during the above mentioned software preservation project).
Since its creation, the emulator has been successfully used for historical reserch described in these publications:
- Stachniak, Z. Learning from Prototypes, IEEE Annals of the History of Computing, vol. 42, no. 2 (2020), pp. 63-71.
- 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.
For more information on the MCM/70, visit the MCM Exhibit.
To obtain a copy of the emulator, please contact York University Computer Museum.