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By
Mary
Bellis
In the early 1970s, anyone wanting
to use a computer had to wait in a long line as computers were few and
far apart. The desire and the market was increasing for a computer that
could be used at home or in the office, the "personal computer". Several
different manufacturers marketed "personal computers" between 1974 and
1977 in response to that desire. These were mainly kits (major assembly
required) advertised in the back pages of magazines like Popular Science.
In the March, 1974, issue of QST
magazine there appeared the first advertisement for a "personal computer."
It was called the Scelbi
(SCientific, ELectronic and BIological) and designed
by the Scelbi Computer Consulting Company of Milford, Connecticut. Based
on Intel's 8008 microprocessor,
Scelbi sold for $565 and came with 1K of programmable memory, with an additional
15K of memory available for $2760. The second "personal computer kit" was
the Mark-8 (also Intel 8008 based) designed by Jonathan Titus. The July
issue of Radio Electronics magazine published an article on building a
Mark-8 microcomputer, information the general public was hungry for. At
the same time, the Intel company introduced the new 8080 microprocessor
chip, made for controlling traffic lights. It was to become the microprocessor
inside the very successful Altair
computer.
 Altair
Computer
An Albuquerque, New Mexico, company
called MITS (Micro Instrumentation Telemetry Systems) was in the calculator
business until Texas Instruments swept the market in 1972 with their low
cost calculators. MITS owner Ed Roberts, a former air force electronics
specialist, then decided to try designing a computer kit. He was aided
by his friend Les Soloman, who happened to be the technical editor for
Popular Mechanics magazine and had been flooded with letters from readers
describing ideas for home computers. Roberts worked together with hardware
engineers William Yates and Jim Bybee during '73 and '74 developing the
MITS Altair 8800. The Altair was named by Soloman's 12 year-old daughter
after an episode from the original Star Trek television series.
The Altair was the cover story for
the January, 1975, issue of Popular Electronics, which described the Altair
as the "World's First Minicomputer Kit to Rival Commercial Models". The
orders for the Altair were huge in response to the article. The computer
kit was shipped with an 8080 CPU, a 256 Byte RAM card, and the new Altair
Bus
design (S100 Bus - the connector had 100 pins) for the price of $400. It
was left to the consumer to put it together, make it work and write any
needed software. This was an uneasy task but the computer was definitely
expandable, cheap and available.
Two young programmers realized that
a software program already written for microcomputers could work on the
Altair. Ed Roberts was soon contacted by Harvard freshman Bill Gates (of
Microsoft fame) and programmer Paul Allen. Within six weeks, Gates and
Allen compiled a version of BASIC to run on the Altair. Allan was offered
a position by Roberts as the Director of Software and the only member of
the software department. Gates, who was then still a student, started working
for MITS part-time after he left school.
BASIC required 4096 bytes of memory
to run, sixteen times the amount of memory the Altair then came with. MITS
created a 4K (4096 byte) memory board that allowed the Altair to run BASIC.
The boards were poorly designed and created problems, and a computer hobbyist
named Bob Marsh designed a better 4k board and started a company called
Processor Technology to sell his Altair compatible boards. Roberts tried
to prevent losing his sales by the BASIC software only with his boards.
He succeeded in promoting the first wide-spread case of software piracy.
Hobbyists everywhere bought a Processor Technology memory board and somehow
found a free copy of BASIC.
Robert's tendency to ship some poorly
designed products might have caused MITS' downfall after a few short years,
but no one can deny that it was the Altair which really kick-started the
home computer revolution. Gates and Allen went on to start Microsoft, becoming
the world's leading software developers. Ed Roberts became a doctor and went on
to practice medicine.
One more computer worthy of note
during this period was the IBM 5100. The 5100 was released in 1975 after
two years of development. It was referred to as "Project Mercury" by the
IBM scientists. The 5100 was IBM's first portable computer and considered
an entry level system, but its $10,000 price tag put it beyond the range
of the hobbyists who bought the Altair. Sales of the 5100 went to small
business and educational institutions who bought the desktop sized minicomputer
which came with BASIC, 16KB of RAM, tape storage and a built-in 5-inch
screen.
Next
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First Home Computers - Apple I, II, Radio Shack's TRS-80 and Commodore
Pet
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©MaryBellis
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