Re: question on LED clock operation

I was responding to previous post, where it was clear that by CPU's we were
discussing single chip based "microprocessors" such as the Intel 8080. These
were originally designed as the heart of "smart terminals" which were
programmable terminals that were designed to be able to emulate other brands
of terminals (to be used to communicate with mainframe computers) but which
did no local processing of data. Each brand of mainframe had its own
associated type of terminal. If you had a data center that needed to
communicate remotely with several mainframes, either you could buy a whole
bunch of different proprietary (and expensive)terminals or a wonderful
chameleonlike Datapoint, which could become whatever type of terminal you
wanted it to be after you loaded the proper emulation from a tape. Hobbyists
discovered that these chips, as a result of their programmable nature, could
be made into stand alone computers even though their manufacturers did not
have this use in mind at all when they were designed. Thus the great
personal computer industry was born almost by accident.
See:

http://www.old-computers.com/museum/computer.asp?c=596


There is no doubt that Von Neumann laid the theoretical ground for computers
but his theories had to be implemented in hardware, which was an entirely
different problem. And reducing that computer hardware to a scale that was
accessible in cost and size to individuals was yet another problem. Just as
Galileo's theoretical work on the period of the pendulum laid the basis for
modern clocks and yet it was left (Huygens) to others to work out
escapements, wheels, etc. to turn the pendulum into a practical clock. And
to others still to reduce the clock to something that you could wear on your
body and was accurate enough to navigate a ship. In the case of the personal
computer, it is as if the balance wheel was first built to be the basis of
say a music box and then almost by accident repurposed for use as the heart
of the pocket watch.




"Joe Sterling" <hanrahanman@xxxxxxxxxxx> wrote in message
news:1166651868.562718.250770@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Jack Denver wrote:
Although it was their thought that CPU's would be used for things like
embedded controllers. It was hobbyists, not the chip producers who
figured
out a way to turn CPUs into the basis for "personal computers" which did
not
exist as commercially produced complete devices.



"Revision" <ttsremove@xxxxxxxxxxx> wrote in message
news:4587b068$0$15449$88260bb3@xxxxxxxxxxxxxxxxxxxx
Historically the time frame between say 1968 and 1975, the companies
building large scale MOS integrated circuits went for supplying the
immediate demand for pocket calculators and clocks. After a few years
of
this they started to look into using the technology to produce "CPU"
chips.

The term "CPU" for "Central Processing Unit" dates back at least to the
early 1950's. The old vacuum tube-based mainframes -- even the first
ones like Eniac -- had CPUs. In fact the basic design of a computer,
due to John Von Neumann -- has not changed since then, despite the
advent of transistors and solid-state miniaturization technologies.
The architecture is the same.

Joe


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