I started on my new ZX-81 replacement board (kit) ZX81+38

[mahjongg]

The layout is coming along nicely, here is a preview, the white lines (ratsnest) are the connections I have yet to make:

[mahjongg]

I have made 100% all connections. The expansion port is not fully wired, but enough for I / O devices such as the printer, and programmable sound generators and the like. I'm going to add ground planes on both sides.

[1024MAK]

Looking a lot better

Mark

[mahjongg]

Almost finished, only nBUSACK and nWAIT have not yet been routed to the expansion port. The layout is now quite "busy".
Next week I will attempt to do the two missing connections.

[mahjongg]

Finished the last two remaining signals, and applied copper fills. Next is to tweak solder mask and silk screen:

[mahjongg]

And this is how the PCB will look like:


Next up, ordering the PCB's (ZX81+38 and keyboard PCB) and testing it.

[8008guy]

What does the keyboard pcb look like?

[mahjongg]

It will look like this:


just with some superfluous stuff removed (reset button and LED's). I also designed a keyboard overlay.

Here you can see a prototype, together with my older ZX-81 clone, built from SMT components.

[8008guy]

Cool!

[nollkolltroll]

Looking very good