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A 1961 Relay Computer Running in the Browser

minivac.greg.technology

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Re: A 1961 Relay Computer Running in the Browser

#31

Post by djmips »

zkmon wrote: post #12

When you attach a name as inventor of something, it sounds as if the whole concept was borne by them, which is not true. All "inventors" and "great leaders" are only carriers of incremental change, which sometimes marks a milestone for a series of changes done by their predecessors or the context. Steam engine concepts were already there before Jame Watt, logic by electrical circuits was already there before Shannon.…

It says, "Designed by Claude Shannon" (at least now it does) - did it formally say invented or what's put the bee in your bonnet?

Re: A 1961 Relay Computer Running in the Browser

#32

Post by JKCalhoun »

gregsadetsky wrote: post #25
JKCalhoun wrote: post #20

Earlier quoted context omitted.

Super cool. And thanks for links to the original manuals for those that want to take a deep dive. Feature request: I was wanting for a bit more sound… I mean, when I see "relay computer", I'm heading there for lots of soft clicks.

More…?! :) I totally feel you - the one reservation is that I’m using (gasp) not the original Minivac Relay sound. I need to go to a Computer Museum that will let me record one to offer a more authentic simulated experience. So tldr - let me get a clean real sound and then we can come back to this question :)

I heard some clicks. I thought they were just the sounds of the switches I was toggling. Are there other (relay) sounds I somehow missed?

Re: A 1961 Relay Computer Running in the Browser

#33

Post by gregsadetsky »

JKCalhoun wrote: post #32
gregsadetsky wrote: post #25

Earlier quoted context omitted.

More…?! :) I totally feel you - the one reservation is that I’m using (gasp) not the original Minivac Relay sound. I need to go to a Computer Museum that will let me record one to offer a more authentic simulated experience. So tldr - let me get a clean real sound and then we can come back to this question :)

I heard some clicks. I thought they were just the sounds of the switches I was toggling. Are there other (relay) sounds I somehow missed?

Just to make sure I'm not misunderstanding:

The relay click sound you're hearing should only happen when a relay turns on, and when it turns off. There is no sound when a button is pressed - you can check this by loading an empty simulator and pressing any of the buttons at the bottom (the simulator won't make any sound):

https://minivac.greg.technology/simulator/

((Once/if I get to see a Minivac in real life, I may learn that buttons do make sounds..))

When a relay turns on and off, a sound is played. In the following circuit, check this by pressing and releasing the button 1:

https://minivac.greg.technology/simulator/#wires=1%2B%2F1C%2...

Re: A 1961 Relay Computer Running in the Browser

#34

Post by ebruchez »

analog31 wrote: post #3
etaioinshrdlu wrote: post #2

"Before microchips existed, computers were built with mechanical relays." Should probably say something about vacuum tubes as well!

And discrete transistors. Now that my curiosity is piqued, I found this nice timeline: https://www.computerhistory.org/timeline/computers/ It looks like transistorized computers were dominant at the point when integrated circuits were introduced.

In particular, the IBM 1401 (two of them actually) that you can see demonstrated at the Computer History Museum in Mountain View are transistor-based and were very successful computers.

https://computerhistory.org/exhibits/ibm1401/

Re: A 1961 Relay Computer Running in the Browser

#35

Post by adrian_b »

gregsadetsky wrote: post #26
bolangi wrote: post #24

Here's a demonstration of a 1958 relay computer. https://youtu.be/_j544ELauus?t=373

Thanks! The Enigma-cracking Bombe (on display at the extraordinary Bletchley Museum of Computing) also used relays https://www.tnmoc.org/bh-10-bombe-description And the Z3 as well! https://en.wikipedia.org/wiki/Z3_(computer)

IBM SSEC, which has started operation at the beginning of 1948, has been for a few years the fastest and most versatile computer in the world (unlike the special-purpose ENIAC) and it has solved a great number of important problems of scientific and technological interest.

It was a hybrid electronic-relay computer, containing more than twenty thousand electromechanical relays and more than ten thousand vacuum tubes.

This is likely the biggest and most complex relay computer ever made, though its main arithmetic part and its fastest registers were made with vacuum tubes, for increased speed in comparison with a pure relay computer.

https://en.wikipedia.org/wiki/IBM_SSEC

Re: A 1961 Relay Computer Running in the Browser

#36

Post by mrandish »

gregsadetsky wrote: post #25
JKCalhoun wrote: post #20

Earlier quoted context omitted.

Super cool. And thanks for links to the original manuals for those that want to take a deep dive. Feature request: I was wanting for a bit more sound… I mean, when I see "relay computer", I'm heading there for lots of soft clicks.

More…?! :) I totally feel you - the one reservation is that I’m using (gasp) not the original Minivac Relay sound. I need to go to a Computer Museum that will let me record one to offer a more authentic simulated experience. So tldr - let me get a clean real sound and then we can come back to this question :)

You may not need to get a museum's cooperation. After a quick search it seems these come up for sale from time to time. I saw one on the Vintage Computer Federation forums offered in 2021 for $500. You may be able to find a collector online who has one and will record the relays for you. A lot of folks have pretty high-quality USB mics for conferencing/podcasting these days.

An alternative might be going to a regional VCF show where one will be (possibly by pre-arrangement with a collector). There are five or six shows held around the country every year. Unlike a museum almost all the devices there are available for hands-on interaction.

Re: A 1961 Relay Computer Running in the Browser

#37

Post by retrac »

artemonster wrote: post #27

shameless plug https://github.com/artemonster/relay-cpu a great and useless hobby project :) 10/10 would do again

Very cool. I've been sketching out a relay computer myself. Mostly unbuilt but I have tested a variety of circuits implementing gates, latches, oscillators, flip flops, counters, registers all using only SPST reed relays.

I'm fixated on speed. I connected some reed relays in a 3 stage ring oscillator and it ran at 1.8 kHz. That has me thinking that with a pipeline 100 instructions a second might be attainable. Reed relay logic seems to be fast enough for a UART at 50 baud. Teletype interactivity is a stretch goal.

My program counter is also 12 bits! And I've also been using Digital to simulate parts of it. Great tool for that.

The current design is RISC-like with a 12 bit word requiring 4 cycles for most instructions. I have an old version of the design specified in gate level Verilog. I should publish that. Though I'm forever tinkering with the control such that it'll probably never be done. Karnaugh maps are like Sudoku.

Re: A 1961 Relay Computer Running in the Browser

#38

Post by mrandish »

gregsadetsky wrote: post #9

Thank you so much everyone, this is something I've worked on for a few years on and off -- I posted about it here in a Show HN a few hours ago [0] The biggest unlock was finding Willy McAllister's excellent Circuit Sandbox [1], which provides the Minivac Simulator's underlying electrical math. I tried so many approaches to simulate electricity (a doomed DIY approach, Falstad, Spice...) but Circuit Sandbox's DC analys…

Thanks for making this! Love the manuals too. It reminds me of the Radio Shack 150-in-one electronics kit I had as a kid.

Re: A 1961 Relay Computer Running in the Browser

#39

Post by gsf_emergency_5 »

aebtebeten wrote: post #15
analog31 wrote: post #3

Earlier quoted context omitted.

And discrete transistors. Now that my curiosity is piqued, I found this nice timeline: https://www.computerhistory.org/timeline/computers/ It looks like transistorized computers were dominant at the point when integrated circuits were introduced.

I like how the 1937 "Model K" adder is literally on a breadboard. (are those knife switches in the upper right?)

U-type flat spring, see fig 2, precursor to transistor

https://www.calling315.com/relay-logic

The user facing switches are 'A' & 'B'

Re: A 1961 Relay Computer Running in the Browser

#40

Post by artemonster »

retrac wrote: post #37
artemonster wrote: post #27

shameless plug https://github.com/artemonster/relay-cpu a great and useless hobby project :) 10/10 would do again

Very cool. I've been sketching out a relay computer myself. Mostly unbuilt but I have tested a variety of circuits implementing gates, latches, oscillators, flip flops, counters, registers all using only SPST reed relays. I'm fixated on speed. I connected some reed relays in a 3 stage ring oscillator and it ran at 1.8 kHz. That has me thinking that with a pipeline 100 instructions a second might be attainable. Reed r…

Oscillator can go high, but real logic is complex and requires realiability. and the fact that cheap relays are absolute crap with a ton toff spread between 3ms to 18ms! The actual clock frequency you can hope for is around 10-15 hz :(
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