Reconfigurable Analog Computers

(arxiv.org)

21 points | by gidellav 15 hours ago ago

6 comments

  • Animats 13 hours ago

    The article mention EAI's SIMSTAR, a real software reconfigurable analog computer from the 1980s. Here's a description of how that worked.[1] This was pretty good. They had a crosspoint of FET analog switches to pass signals around, so they managed to do this in solid state, without relays. They had a M68000 as a control machine to set up connections. It all worked well enough to allow a real time man-in-the-loop simulation of the F-16 control system.[2] Just barely. The USAF paper says that the biggest problem was keeping the SIMSTAR analog computers alive.

    Analog FPGAs have been made, downsizing this sort of thing to chip size. But not recently. The problems seem to be 1) lack of a use case, and 2) noise.

    Analog computing is all about noise minimization. This is Not Fun.

    There's interest in this stuff for neural nets, which do a lot of clipping and may be less noise-sensitive.

    [1] https://www.analogmuseum.org/library/simstar_technology.pdf

    [2] https://apps.dtic.mil/sti/tr/pdf/ADA189675.pdf

    • buildbot 12 hours ago

      Does https://en.wikipedia.org/wiki/Cypress_PSoC Count? I’ve kinda wanted to try one out but have 0 use case…

      • duskwuff 7 hours ago

        Not really. The amount of analog hardware on die is minimal - it's little more than a few multiplexers surrounding the standard sorts of analog peripherals you'd see on a microcontroller like ADCs/DACs/comparators.

  • Marshferm 14 hours ago

    Ullmann to the rescue. We’re indifferent to analog computers like Detroit was once with electric cars.

    • Locutus_ 12 hours ago

      Ahhh, Vaxman still up to his usual shenannigans :-)

      • Marshferm 11 hours ago

        Imagine that, a self-organizing, self-learning software that builds its own hardware. Even dumb primates like us can build ‘em!