20 Jul
2024
20 Jul
'24
3:46 p.m.
A fair clarification, I realize that I was sort of mixing two different
topics (and didn't mean to imply it had anything to do with analog
computing).
What I meant was that in the title of the book they use "digital computer"
and I wonder if there was ever a book describing a mechanical "analog
computer" - and what they might even look like.
It's also funny to me they've inserted the word "working" (I wonder if
that
was a subtle tribute to the Babbage machine, which at the time wasn't
confirmed to be a working system -- I've read that the Mark-1 was largely
inspired as an intent to realize the Analytic Engine, but the Mark-1 does
include numerous "electro" upgrades probably to make the implementation far
more practical and more useful in the end).
and - thanks on the notes for ternary computers (and also references to
where this "paperclip computer" has been realized in the past!).
-Steve
On Sat, Jul 20, 2024 at 2:03 PM Bill Degnan via cctalk <
cctalk(a)classiccmp.org> wrote:
I should add, the paperclip computer was a mechanical
computer, not an
analog computer in the 50-60's sense of the term.
b
On Sat, Jul 20, 2024 at 2:05 AM Bill Degnan <billdegnan(a)gmail.com> wrote:
Steve
You ask a lot of good questions.
The story is pretty well documented. There was a company that made a
commercial version of the computer described in the book
https://blog.adafruit.com/2013/05/08/how-to-build-a-working-digital-compute…
There is a nice paperclip computer at the System
Source museum in Hunt
Valley, MD.
I am sure there are people who actually built homebrew versions by
following the book but I have never seen one.
Analog computers are not like quantum computers enough for a valid
comparison. Different era, different uses. Quantum computers are still
digital computers and they're really nothing like analog computers of the
50's-late 60's.
Analog computers were wired to complete a circuit that performs a
mathematical function circuit. The inputs and outputs are voltages or
other electronically-measurable forces such as vibration. When an analog
computer program runs the output is sent to a voltmeter, oscilloscope,
plotter or counter, or custom device. A person would take the plot
(waves,
plotted points, etc.) and measure the slope or
wave frequency manually by
performing additional calculations with a slide rule or feeding the data
into a digital computer for analysis. Think smart programmable
thermostat.
Analog computers are more like open-use peripherals that can be
programmed
to do one thing at a time over and over. Analog
computers often
had amplifier tubes which were used to generate input voltage pulses to
be
fed into the program circuitry. I am just
touching the surface, but hope
that explains what they did. They're no longer used for general
computing
because now we have USB devices that do analog to
digital conversion
50's-60s' analog computer programming is done by patch panel.
BIll
On Fri, Jul 19, 2024 at 10:58 PM Steve Lewis via cctalk <
cctalk(a)classiccmp.org> wrote:
> Last month, I got to speak at VCF SW on aspects about the history of
> personal computers.
> https://www.youtube.com/watch?v=fpF6Ofrr6_0
> (I botched a couple things, a link to corrections is in the Description)
>
> I brought up the 1968 book "How to build a working digital
> computer"(Alcosser). I was wondering about opinions here on that book -
> was it at all influential at the time? Or is anyone aware of
actually
> building the system it describes?
>
> And - any thoughts on "digital computer" vs analog? I'm aware of
early
> Heathkit analog computers. Is it fair to say quantum computing is sort
of
> a return back to analog computing?
>
> I recently heard someone make a comment that we're near the end of the
> "3.3V era" (maybe this was in the recent X16 talk, where some of the
> challenges of the recent retro-remakes is exploring back to the 5V era
and
how
it's getting more difficult to find modern-make components that
support
that).
Has no one explored a "tri-state" system? (discrete regions across 5V?)
- Steve
(v* voidstar tech, not to be confused with voidstar labs)