Hi all,

I've built a custom 6502 computer that I thought might be of interest here:

https://github.com/nickbild/vectron_64

I hope you enjoy!

Nick

Welcome Nick - excellent project! Spookily enough your project got a mention not very many minutes ago:
viewtopic.php?f=1&t=5607

Looks good - I like the "modern" PS/2 keyboard with the character LCD too

(I picked it up from Adafruits site and posted it here earlier, hope you don't mind!)

Cheers,

-Gordon

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Gordon Henderson.
See my Ruby 6502 and 65816 SBC projects here: https://projects.drogon.net/ruby/

Not at all. Happy to see it being shared -- I spent a lot of time on it!

Is there a schematic? I couldn't find one, except maybe a file that requires a particular CAD to render.

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http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

There's the breadboard view posted, or you need Fritzing (free software) to see formal schematics.

I had a look, since I use Fritzing... the schematic page hasn't been "worked", so what you have there is all there really is.

Fritzing is somewhat interesting in that it has 3 ways to do a design - you can use the breadboard view (which you see here), or the schematic capture view or the pcb layout view. When you do something in one view, components, wires, etc. are added to the other views, but no-where sensible. You can drag things about though. I use the breadboard view for trivial things that stay on breadboards - it's easy to see, makes nice colourful pictures and are easy to replicate, and for simple things easy to go directly to the PCB stage, if needed.

For bigger stuff I start on the schematic view and flip between that and the pcb view, ignoring the breadboard view.

Fritzing is far from perfect, comes in for a lot of criticism, but for simple stuff, it's quick and easy although I have to say; this is (impressively) one of the most complex breadboard layouts I've seen done in Fritzing!

Cheers,

-Gordon

_________________
--
Gordon Henderson.
See my Ruby 6502 and 65816 SBC projects here: https://projects.drogon.net/ruby/

Thanks for the feedback. This is probably where I should mention that this is my first substantial electronics project. Professionally I'm in software, and have no formal EE or CE background. I made it up as I went along, so I'm sure it's a bit amateur -- I'm in the category where I'm just excited that it works!

Keep going! I've done a lot of small arduino type projects using Fritzing and I recently did my Ruby 6502 PCB with it too, although it's actually less complex than yours in some ways. If I'd not been using Fritzing for the past 7 years I'd really make the effort to switch to KiCAD, however there's that 7 years worth of being used to it...

Cheers,

-Gordon

_________________
--
Gordon Henderson.
See my Ruby 6502 and 65816 SBC projects here: https://projects.drogon.net/ruby/

> I'm just excited that it works!
I'm with you there, and I think a lot of others will be too.

Breadboard computers are cool, so I love it.

A minor nit, from the memory map it looks like you reserved some LCD variables in page zero. I would imagine LCD interaction is fairly limited to intermittent character I/O, so the advantages of page zero are wasted. Personally I prefer to use page zero for a Forth like parameter stack, pointers to other blocks of memory, or data elements where the extra cycles are needed.

You're right that I wasted a little zero page on that. I used it because it simplified address decoding for me at that stage. I discovered the wonder of magnitude comparators at a later stage of the build. I'd definitely do some things a bit differently if I were to start with the knowledge I now have.