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Zusie – My Relay Computer

Zusie – My Relay Computer

19 comments

·January 31, 2025

rahen

Another relay computer for those interested, with hand built DRAM! http://www.northdownfarm.co.uk/rory/tim/tim-8.htm

dahart

So cool! Should link to the project homepage http://www.nablaman.com/relay/ Or the news page with pics & videos. http://www.nablaman.com/relay/progress.php Last update was in 2011, btw.

bittercynic

That's beautiful and mesmerizing - video here: http://www.nablaman.com/relay/progress.php

I built one of these[0] a few years ago, and really enjoyed the build process and playing around with it. It was a pretty big project, but no special skills required.

[0] https://relaysbc.sourceforge.net/

sitkack

The creator of relaysbc posts here every so often.

The bare PCB is here https://www.tindie.com/products/jhallen/single-board-relay-c...

I have not completed mine yet, what was the hardest part during assembly or the gotcha you had to debug?

bittercynic

I think the hardest part was trying to clean the flux off of the board, and I never did get it that clean.

I chose to use sockets for the relays, and at first it had some weirdly inconsistent behavior. Removing and re-installing all the relays fixed it, though.

I went very slowly and checked my work as I went. I don't understand the circuit well enough to debug it, so I was very motivated to work accurately.

ggerules

This is a very cool project!

I wish this was around when I was teaching computer architecture. I use to challenge students to think outside the box when it came to switchs. One example is to build a computer out of paperclips.[1] The book can be found on eBay, Amazon and other used/old book outlets.

[1] "How to build a working digital computer", Edward Alcosser, 1968

sho_hn

I 3D printed some Zuse-style mechanical NAND gates last year, that was a lot of fun and makes for a great fidget toy:

https://mero.ng/i/vMdqQYJG.jpg

I've kind of given some thought of doing a higher-quality metal production run of these with nice finish and engravings of the inputs and outputs as a geeky desk fidget.

Model credit goes here (and of course to the original Zuse patent application the design is from), although I made a NAND remix as I wanted a universal gate and fixed up all of the tolerances and still really have to upload my version:

https://www.printables.com/model/69642-zuse-inspired-z1-logi...

dang

Related. Others?

Zusie – My Relay Computer - https://news.ycombinator.com/item?id=8711869 - Dec 2014 (21 comments)

EvanAnderson

As of late I've been watching a Youtube creator, DiPDoT[0], building a relay computer.

DiPTDoT's project is still in-progress. His computer has an 8-bit data bus and a 16-bit address bus[1], like the Zusie. His registers are a little more generous than the Zusie.

I really enjoy the sound of DiPDoT's test rigs running his cards thru functional testing. The rhythm of a relaying computer running code with loops is probably pretty fun.

[0] https://www.youtube.com/@dipdoting

[1] https://youtu.be/GwNZFNtruTY?t=60

alnwlsn

One of the most polished diy relay computers (and video series) I've seen is by Paul Law [0]. He's been working on it for over 10 years, and has just started a series on using it to calculate Pi.

[0] https://www.youtube.com/@paul80nd

artemonster

the guy uses same relays as I do and he solders them onto pcb. Ive learned my lesson the hard way that these relays are unreliable and they do die, so in my design all of relays are socketed. hope the guy will adjust his design too

artemonster

Shameless plug for my relay computer: https://github.com/artemonster/relay-cpu

gwbas1c

I'd love to see, and hear, a video of the computer in operation

myth2018

gwbas1c

I see "This video displays Zusie the Relay Computer...", but there's no actual video to see.

creer

There is now a whole bunch of relay computers on youtube! It's become easier to do it seems. This one 2011, some more recent on youtube.

genpfault

(2011)?

guerrilla

> 8-bit data bus and 16-bit address bus

What? That is very intense. If I were doing relays, I would have gone for 2 bits or something, 4 bits max. Hardcore.

creer

Agreed, 8-bit data, 16-bit address (but 12-bit program counters) is massive for relays! That's a lot of relays to do anything. But it turns out their start was when they stumbled on 1500 relays in good condition. So they were set in relays from the start and could aim "rather" big. They do have a lot of relays.