Lecture 10. Computer at home and the per-
sonal computing paradigm
Informal and unedited notes, not for distribution. (c) Z. Stachniak, 2011.
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Introduction: microcomputers for home
Volume manufacturing of microcomputers for commercial markets began in
1973. Microcomputers were primarily employed as embedded control systems
(e.g. French Micral) but also as data processing units for business, research,
and educational applications (e.g. Canadian MCM/70).
It was not before late 1970s, when general purpose microcomputers were
manufactured in hundreds of thousands of units per year. This sudden de-
mand for microcomputers was caused, in part, by the introduction of mi-
crocomputer hardware and software capable of supporting small business
operations and computer literacy programs.
In 1977, Commodore introduced its all-in-one PET 2001 computer aimed
at business while Apple Computer unveiled its Apple II which would soon
attract a lot of attention from nancial analysts and planners due to the
popularity of the VisiCalc spreadsheet program developed for that computer
by Personal Software Inc. A VisiCalc machine, i.e., an Apple running Visi-
Calc software, demonstrated that a microcomputer could be an eective,
personal productivity tool that did not require any computer hardware or
programming skills from its user.
1 Fig. 1. Commodore PET exhibit during Vintage Computer Festival, 2004. Photograph
by Z. Stachniak.
But the main reason for the marked increase in microcomputer sales was
the invention of a new consumer electronics gadget the home computer.
Since 1977, a number of computer, semiconductor, and consumer electronics
companies had begun to manufacture rudimentary but complete microcom-
puters for home applications and started to sell them in large quantities
through chains of large department stores, dedicated computer stores, and,
in some cases, through manufacturers own retail outlets (for instance, by
1979, Tandy Corp. sold over 100,000 of its small TRS-80 Model 1 computers
through its vast North American chain of outlets).
2 Apple Computer, Atari Inc., Commodore, Tandy Corp., and Texas Instru-
ments were among the rst companies to oer home computers but they were
soon followed by numerous other rms, some of which had no prior experi-
ence with digital hardware manufacturing.
Fig. 2. A Timex Sinclair TS-1000 home computer ad in Science Digest, October 1982.
3 At the core of the home computer concept there was an assumption that a
computer at home should serve the needs of all members of a family regard-
less of their knowledge of computer hardware or software; in fact, none was
assumed essential for the home utilization of microcomputers.
As opposed to hobby computers, the home computer hardware was not sup-
posed to be tampered with; all that a user had to do was to connect the
power cord and peripherals via clearly marked ports and to locate the on/o
switch. As for software, all major home computer manufacturers provided
a variety of application programs and at least one programming language,
mostly BASIC, in accord with an educational doctrine which expected an
educated individual to be uent in at least one programming language.
The BASIC programming language was easy to learn, easy to use, and could
run on machines equipped with small amounts of memory.
Computer hobbyists rejected the home computing paradigm outright and
considered computers for the masses a consumer electronics product doomed
to failure, a solution looking for a problem.
However, the consumers reaction proved otherwise. By 1980, there were over
120,000 Apple IIs while Tandy sold over 175,000 of the TRS-80 microcom-
puters. The sales of tiny Sinclair ZX-80 and ZX-81 computers introduced in
1980 and 1981, respectively, reached 400,000 by 1982! In the same year, there
were over 800,000 small Commodore VIC-20s world-wide. Sales reached the
one million mark in early 1983 when Commodore was shipping its VIC-20s
at the rate of 100,000 units a month.
In 1983, two other manufacturers joined the one million club: both Texas
Instruments and Apple Computer shipped over one million of their TI-99/4A
and Apple II computers. In 1984, there were over 2 million Apple IIs and,
perhaps, even more Commodore 64s, arguably the worlds most successful