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Am also noob. Another question: Is there a connection between clockless and analog computing? I dimly recall reading about Ivan Sutherland (and maybe Sun Comp

Am also noob. Another question: Is there a connection between clockless and analog computing? I dimly recall reading about Ivan Sutherland (and maybe Sun Computers) pushing clockless. And for some reason I associated the two strategies. I (think I) get that analog is continuous function. And I think of clockless as like async and queues from high level programming languages. Thanks for humoring me.

jacquesm 4y ago
Analog computers are - in all cases that I'm familiar with - clockless. With respect to Sutherland, I think you're talking about 'fleet', which was a digital async solution, HN discussion from back in the day (13 years ago, all resources seem to have vanished): https://news.ycombinator.com/item?id=723882 https://news.ycombinator.com/item?id=723882
- adrian_b 4y ago
  It is possible to do analog processing of signals that have been sampled in time, using a clock signal, but which have not been quantized in amplitude. Some circuits of this kind are widespread, e.g. the so-called switched-capacitor filters or the so-called charge-coupled devices (CCD), which are used in many image sensors. It is possible to make an analog computer that works like a synchronous digital computer, with all operations done under the control of a central clock signal. In such an analog computer, the digital registers of a digital computer are replaced by capacitors which store electrical charges that are the analog quantities corresponding to the numbers stored in the digital registers of the equivalent digital computer. Such a synchronous analog computer would be slower than an analog computer that works in continuous time, without a clock, but the synchronous analog computer can be made to have a higher precision, because its precision can be made to depend only on area ratios between capacitors, and such ratios can be very stable during aging or temperature variations. In an analog computer with continuous time, without a clock, the precision is also influenced by other kinds of electrical components, at least by resistors, and in integrated circuits it is difficult to make high-quality resistors.
  - jacquesm 4y ago
    That's an interesting idea. I haven't seen that kind of hybrid in real life, the closest thing I can think of is called a bucket brigade: https://en.wikipedia.org/wiki/Bucket-brigade_device https://en.wikipedia.org/wiki/Bucket-brigade_device

jacquesm 4y ago

Analog computers are - in all cases that I'm familiar with - clockless. With respect to Sutherland, I think you're talking about 'fleet', which was a digital async solution, HN discussion from back in the day (13 years ago, all resources seem to have vanished): https://news.ycombinator.com/item?id=723882 https://news.ycombinator.com/item?id=723882

adrian_b 4y ago
It is possible to do analog processing of signals that have been sampled in time, using a clock signal, but which have not been quantized in amplitude. Some circuits of this kind are widespread, e.g. the so-called switched-capacitor filters or the so-called charge-coupled devices (CCD), which are used in many image sensors. It is possible to make an analog computer that works like a synchronous digital computer, with all operations done under the control of a central clock signal. In such an analog computer, the digital registers of a digital computer are replaced by capacitors which store electrical charges that are the analog quantities corresponding to the numbers stored in the digital registers of the equivalent digital computer. Such a synchronous analog computer would be slower than an analog computer that works in continuous time, without a clock, but the synchronous analog computer can be made to have a higher precision, because its precision can be made to depend only on area ratios between capacitors, and such ratios can be very stable during aging or temperature variations. In an analog computer with continuous time, without a clock, the precision is also influenced by other kinds of electrical components, at least by resistors, and in integrated circuits it is difficult to make high-quality resistors.
- jacquesm 4y ago
  That's an interesting idea. I haven't seen that kind of hybrid in real life, the closest thing I can think of is called a bucket brigade: https://en.wikipedia.org/wiki/Bucket-brigade_device https://en.wikipedia.org/wiki/Bucket-brigade_device