The Day After - Inventing the PC - page 136

of the main problems was whether the ROM chips containing
the MCM /70's operating software could be reused in a new
computer. For its MCM /70 project, MCM had contracted Elec-
tronic Arrays to fabricate large quantities of such ROM chips
at a time when the company was still aiming at a monthly sales
target of 1,000 MCM computers for 1975. However, by the end
of 1974, these production targets had had to be substantially
scaled down, but the ROM chips from Electronic Arrays were
piling up. “Now, how do you develop a computer that would
make use of these read-only memory chips, and the binary code
that Gord [Ramer] and Don [Genner] had put together?” asked
Laraya in an interview. “After all, it was a big [software] system
that took a long time to debug.” With this question, Laraya was
hinting at one of the main obstacles MCM had to overcome if
it wanted to re-use these ROM chips in new products: the soft-
ware contained in these chips was tightly connected to the Intel
8008's architecture. In other words, the chips were meant to
operate with the 8008 microprocessor, and if MCM wanted to
re-use them, it had to find a way to replicate the 8008 processor.
And this is exactly how MCM 's new computer - the MCM /800 -
was put together. The computer's central processing unit was
built using a large number of TTL semiconductor devices. It was
able to execute the same instruction set as the 8008 but at a
much higher speed. With this design shortcut, the company was
abandoning, forever as it turned out, the microprocessor tech-
nology path on which it was founded.
The MCM /800 was packaged in a new case and had an inter-
nal fan to dissipate heat - the feature so passionately discussed
during the MCM /70's development. But like the /700 model, the
new computer was difficult to upgrade and service.
MCM announced its new computer in July 1976 and adver-
tised it as “the combination of data processing and word pro-
cessing for as little as $400 a month.” It was targeted at problem-
solving and small business markets. “A typical business system