Well thanks to a faulty monitor my ZXPand+AY has bitten the dust after it put 96vac down the audio lead. Looks like the PIC, Gals and ROM at least are dead and possibly the AY chip. So basically every chip on it.
I gather these are no longer available? (I have no way of programming a GAL chip or the PIC)
Dead ZXpand
Re: Dead ZXpand
OK so after burning a new rom and swapping the PIC chip out with the one from my ZX80 ZXPand I have identified the PIC chip as faulty.
Can this just be replaced or does it need to be programmed first?
Thanks
Can this just be replaced or does it need to be programmed first?
Thanks
Re: Dead ZXpand
Actually it seems to have updated the chip fine after the swap.
Now to test the AY
Now to test the AY
- 1024MAK
- Posts: 5165
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Dead ZXpand
Yes, PIC chips are easy to program, you need a PICkit programmer. The clones of the PICkit2 from China are apparently okay. Or you can buy the latest official version from Microchip.
I can’t remember if the ZXpand has holes/pads for a in circuit programming pin header. But it’s not hard to solder a IC socket and pin header to a piece of stripboard. Then wire it up.
A working PIC in a working ZXpand can have its “firmware” updated from the SD card.
Mark
I can’t remember if the ZXpand has holes/pads for a in circuit programming pin header. But it’s not hard to solder a IC socket and pin header to a piece of stripboard. Then wire it up.
A working PIC in a working ZXpand can have its “firmware” updated from the SD card.
Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor 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 being good this year.
ZX81 Chip Pin-outs
ZX81 Video Transistor 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 being good this year.
-
- Posts: 17
- Joined: Thu Aug 06, 2020 11:29 am
Re: Dead ZXpand
I got in touch with sirmorris when my zxpand died and he was happy to repair it. If you have trouble with yours get in touch with him and see what he says. Worth a shot!