Sinclair ZX80 / ZX81 / Z88 Forums

Finally I got my ZX81 from Danish distributor to work again with Andy Rea's new ULA.

I found a second cut on the pcb from the destructive removal of the old ULA. So now there's 2 wires on the bottom of the pcb, and it works great, and a new transistor has been inserted where one was removed in the debug fase.

You can even see the inverse screen created by Andy's custom firmware.

Now off to bed. Tomorrow will bring new adventures with enabling of the ULA's M1NOT feature and maybe enabling of composite output.

Thanks again to everyone here helping me to resurrect this old friend.

And now a monitor is connected and M1NOT modification added temporarily with the white jumper wire

Excellent work Martin.

Another one comes to life and thanks for reminding me about the inverse video I had forgotten about that.

Good to hear that you have got your ZX81 working.

That board does look it has been through the wars though...

Mark

My old soldering iron was not easy on any boards