Information Technology Reference
In-Depth Information
ally feasible product relied on a number of assumptions. One of
them was that the rapid progress in semiconductor technologies
would lead swiftly to inexpensive and high-capacity memory
devices. The core memory routinely used in mainframes and
mini-computers was large and inappropriate for Kutt's com-
puter. The first semiconductor memory chips were small but,
unfortunately, they were also expensive and of low capacity. For
instance, the Intel 1101 random access memory (
RAM
) chip was
a tiny device (less than a centimetre in length and less than half a
centimetre wide) but it could hold only 256 bits of information.
If a computer's
RAM
capacity were to be, say, 64,000 bits (i.e.,
eight thousand 8-bit words or 8K), then its
RAM
board would
have to contain two hundred and fifty 1101 chips. In 1971, at
a cost of, say, $12 a chip, that would add up to $3,000 - or the
equivalent of a new Ford Grande Mustang with a vinyl top and
a Grande logo beside the rear window! One of the early Intel
bestsellers - the 2102
RAM
chip, which would be eventually
employed in the
MCM
/70 - had a memory capacity of four 1101
chips. But in 1973, one had to pay $20 per chip, or $1,280 to
external storage, display, and
APL
software.
Of course, the biggest gamble of the enterprise was the as-
sumption that the 8008 microprocessor, or one of its succes-
sors, if ever developed, would be able to reliably support all the
functions of Kutt's computer. The first commercially available
microprocessor, the Intel 4004, was introduced in November
of 1971. The processor, together with three supporting chips,
was designed by Intel for a Japanese client and was meant
to be used in a series of desktop calculators. The calculator-
oriented design of the 4004, as well as the very limited amount
of memory which the chip could directly access (just four thou-
sand 4-bit words), meant that no practical, general-purpose
computer could be built around it. However, the first 8-bit pro-
