What is the absolute smallest instruction set do you need to make aworking computer?

On 2019-09-22 8:36 p.m., pyotr filipivich wrote:
"J. P. Gilliver (John)" on Sun, 22 Sep 2019
21:15:45 +0100 typed in alt.windows7.general the following:
In message , pyotr
filipivich writes:
[]
Martin Gardner had an article about a "theoretical" 'primitive
computer using pulleys and ropes in place of transistors (or tubes).
In theory it would work, in practice there would be too much
imprecision from the slack/stretch in the ropes for it to work.

Babbage (arguably only with modern materials) made a mechanical machine
work. There are the mechanical equivalents of squaring circuits,
thresholds etcetera. Electronic computers could be made to work with
three or four voltage levels rather than two - it just reduces the noise
margin, which puts limits on speed and distances. Presumably a
pulleys/ropes machine could be made, as long as there were thresholds,
and the mechanical equivalents of amplifiers (a rope-operated clutch
perhaps? I'm not really a mechanical engineer).

It is funny in a way. Garden was reporting a supposed "discovery"
of a "computer" discovered on a south pacific island. Yes, one could
probably be made to work. Wintergatan - Marble Machine has made what
was originally a CGI video into a working machine.
https://www.youtube.com/watch?v=IvUU8joBb1Q A fascinating study in
its own right.


Absolutely wonderful machine and a brilliant inventor/builder. I didn't
know it existed.

Rene

Rene Lamontagne on Sun, 22 Sep 2019 22:31:28 -0500
typed in alt.windows7.general the following:
On 2019-09-22 8:36 p.m., pyotr filipivich wrote:
"J. P. Gilliver (John)" on Sun, 22 Sep 2019
21:15:45 +0100 typed in alt.windows7.general the following:
In message , pyotr
filipivich writes:
[]
Martin Gardner had an article about a "theoretical" 'primitive
computer using pulleys and ropes in place of transistors (or tubes).
In theory it would work, in practice there would be too much
imprecision from the slack/stretch in the ropes for it to work.

Babbage (arguably only with modern materials) made a mechanical machine
work. There are the mechanical equivalents of squaring circuits,
thresholds etcetera. Electronic computers could be made to work with
three or four voltage levels rather than two - it just reduces the noise
margin, which puts limits on speed and distances. Presumably a
pulleys/ropes machine could be made, as long as there were thresholds,
and the mechanical equivalents of amplifiers (a rope-operated clutch
perhaps? I'm not really a mechanical engineer).

It is funny in a way. Garden was reporting a supposed "discovery"
of a "computer" discovered on a south pacific island. Yes, one could
probably be made to work. Wintergatan - Marble Machine has made what
was originally a CGI video into a working machine.
https://www.youtube.com/watch?v=IvUU8joBb1Q A fascinating study in
its own right.


Absolutely wonderful machine and a brilliant inventor/builder. I didn't
know it existed.

It is a fascinating machine, both from the design concept through
to the latest build. Fascinating as well are the machinist bits (the
variable speed clutch to adjust timing for the kick drum).
In my boxes of book I have the 4 volume set of "Ingenious Devices"
- or "How we did this before stepper motors and computer controls."

--
pyotr filipivich
Next month's Panel: Graft - Boon or blessing?