backplane

[sirmorris]

I've looked about and I can't find any schematics / plans / crayon drawings of an expansion backplane for the zeddy.

I'd like to add 2 or 3 cards at a time - 32k ram, IO, keyboard. I was planning the layout of my keyboard interface last night and having a pass-through is just going to amplify any wobble problems. I'd rather have something solid that I can use with untouched zeddies.

Do you know of one? I could knock one up in eagle-cad of course, but if there's a tried and tested one available I'd rather spend my time in other ways

C

[BrunoFlorindo]

I know there's instructions, not schematics nor eagle files, for backplane expansion PCBs for the ZX81 and TS2068, but I can't remember where I saw it. It might be on the book 'Powerful projects for your TS2068', which can be adapted for the ZX81, or in one of the Sync magazines. Sorry. I've been scanning so much stuff this week that I'm getting confused. :/

I'm waiting for another book to arrive, a whole book dedicated to hardware projects for the ZX81. I will see if it has what you're looking for. And I'll scan it and upload it too, very soon I hope.