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.
Help in resurrecting my ZX81
Re: Help in resurrecting my ZX81
And now a monitor is connected and M1NOT modification added temporarily with the white jumper wire
Re: Help in resurrecting my ZX81
Excellent work Martin.
Another one comes to life and thanks for reminding me about the inverse video I had forgotten about that.
Another one comes to life and thanks for reminding me about the inverse video I had forgotten about that.
- 1024MAK
- Posts: 5118
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Help in resurrecting my ZX81
Good to hear that you have got your ZX81 working.
That board does look it has been through the wars though...
Mark
That board does look it has been through the wars though...
Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
Re: Help in resurrecting my ZX81
My old soldering iron was not easy on any boards