/cyber/ - Cyberpunk & Science Fiction★

>>48346 (OP)

I've alwayswanted to build my own with a 6502 ever since i fell in love with it's assembly language, but never got around to it… It still interests me a lot to see people building and programming them from the ground up, and i could see some truly great ideas from from those kinds of projects

I looked into making a TTL computer once, you can look up TTL computer and find homemade computers that are made with kinda simple components that are a bit easier to understand

If you're interested in the z80, here's an article on it from last month; https://hackaday.com/2017/10/26/hackaday-prize-entry-the-minimalist-z80-computer/

>>48346 (OP)

That's an ambitious project. You might want to start modestly, but whatever you do, please please post here from time to time so we can learn from your mistakes.

There's my father's old Soviet ZX Spectrum clone lying on my table, and I'm trying to resurrect it.

>ZX Spectrum was the cheapest home micro computer on European market, beating competition by a margin.

>Despite that Sinclair still managed to make massive profits from it, because it was literary built from garbage.

>When schematics reached Soviet block, people there didn't have access to any good components and had to cut down costs even further.

>Out of all Soviet speccy clones, Leningrad-1 is considered to be the cheapest and shittiest one.

>Leningrad-1's schematics and PCB mask were copied with a malfunctioning fax machine, introducing an additional error, that could destroy your ICs.

>unpopulated PCBs made with that mask were sold on grey markets across provincial parts of Russia, where my father got a hold of one.

>In addition, my father couldn't find some required ICs while building this thing and had to improvise.

>Later on the board was used as a donor for other projects and then was rotting in a garage at the bottom of some box for ~20 years.

So you can imagine the depth of the situation I've gotten myself into.

And considering my lack of experience with restoration, I'm seriously in over my head.

There's rust flakes everywhere, capacitors look like someone chewed them, lots of components missing.

Even some PCB traces are falling off, and when you fix one thing, two other things break.

For now I replaced the oscillator and even got almost stable video signal out of this thing.

CPU appears to be working too, but only when I take it out of PCB and stick into a breadboard.

On the other hand, when I hook power directly to the board, I have a serious voltage drop (from 5V to fucking ~4.3V) and CPU doesn't get enough juice to start up.

So, I'm not sure what to do next.

I kinda want to restore it to it's former glory and turn it into some kind of /cyber/ family relic.

But, objectively speaking, this thing never was glorious to begin with, and patching up PCB is a lot of work and result will be ugly mess.

On the other hand if I'm going to replace PCB with new one, I might as well go all the way and get better schematics or even ditch ZX Spectrum completely and implement a better Z80 machine.

But it feels like I would lose some of that "relicness" in the process.

I think I'd probably do an Apple clone, just because there's more information and the parts are probably easier to find.

Check this series out: https://www.youtube.com/watch?v=ZXllm5JWWAs

The thing that holds me back, though, is questioning what I'd use it for? There are projects to take something from this generation and add an ESP8266 modem, so you can do text BBS systems again, but you can more easily do that with any widely available CHIP or Pi Single Board Computer.