It should certainly be possible but it may not be pretty
Is that a commission or a rhetorical question? 
"Different" ZX81's
Re: "Different" ZX81's
I have a crazy idea about making improvements that are compatible with stock hard/soft-ware switchable.
I am getting the idea I may need to get the V2 zpand and was interested in making it battery powered with LCD screen so the need may be there.,.Ill get back with you.
Twisted threads... this should go with the K2 thread...
I am getting the idea I may need to get the V2 zpand and was interested in making it battery powered with LCD screen so the need may be there.,.Ill get back with you.
Twisted threads... this should go with the K2 thread...
The answer is yes.
Wait I have my own project I was suppose to do the same with. I'll shutup now (but secretly wish for someone to take up the task...)
Did I just type what I was thinking and press enter?
5-TS1000,UK ZX81<-Sheelagh, US ZX81, 2-TS1500/KDLX , 3-TS2040 printer, 2-TS2020 cassette decks, ZXPAND+AY, ZeddyNET, ZXBlast, UDG, ZX8CCB, AERCO, BUILDS/REPAIRS ZX Spectrum, ZX80 Minstrel, ZXMAX48 v1 v2, 2-TS-2068, ROM, 16kRAM
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Lardo Boffin
- Posts: 2256
- Joined: Sat Nov 26, 2016 2:42 am
Re: "Different" ZX81's
A nice working issue three that came in a new sleeve type box.
Looks like they could not be bothered to fill the vias with solder on this one!
Anyone know why some of the issue threes have an extra capacitor down by the 7805?
Looks like they could not be bothered to fill the vias with solder on this one!
Anyone know why some of the issue threes have an extra capacitor down by the 7805?
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
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Lardo Boffin
- Posts: 2256
- Joined: Sat Nov 26, 2016 2:42 am
Re: "Different" ZX81's
A working issue one that came in a brown postal box.
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
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Lardo Boffin
- Posts: 2256
- Joined: Sat Nov 26, 2016 2:42 am
Re: "Different" ZX81's
And a not working (not booting to the K, just a white screen, not swapped the ULA yet) early issue one. This one came with the ZX80 PSU that is minus the jack plug.
Amusingly this one was sold as an un-used kit! That was 'probably never used, ever!' I assume this was because the modulator is missing?
Also someone has attached wires underneath - possible a battery mod?
The ROM looks like it could be a bugged version judging by the number. Will put it in another zeddy and find out.
Regardless it was cheap, boxed and the case the zeddy is in is rather good! As is the very good condition issue one manual.
Amusingly this one was sold as an un-used kit! That was 'probably never used, ever!' I assume this was because the modulator is missing?
Also someone has attached wires underneath - possible a battery mod?
The ROM looks like it could be a bugged version judging by the number. Will put it in another zeddy and find out.
Regardless it was cheap, boxed and the case the zeddy is in is rather good! As is the very good condition issue one manual.
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
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Lardo Boffin
- Posts: 2256
- Joined: Sat Nov 26, 2016 2:42 am
Re: "Different" ZX81's
And here we have a truly different ZX81.... Well, kind of.
All the way from the US of A!
All the way from the US of A!
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
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1024MAK
- Posts: 5529
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
- Contact:
Re: "Different" ZX81's
Nice 
Have you figured out how to get a video signal displayed yet?
If yes, does it work?
Mark
Have you figured out how to get a video signal displayed yet?
If yes, does it work?
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
Spring approaching...
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
Spring approaching...
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Lardo Boffin
- Posts: 2256
- Joined: Sat Nov 26, 2016 2:42 am
Re: "Different" ZX81's
This one seems to be missing some bits...
Ohhh shiny!
Ah here they are!
Looks like a few evenings of very anxious soldering!
Ohhh shiny!
Ah here they are!
Looks like a few evenings of very anxious soldering!
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Re: "Different" ZX81's
"LARDO STEP AWAY FROM THE SOLDERING IRON! 
Serious face, when you hinted that you 're going to assemble this little beauty my heart sung, no display cabinet for this one build it and use it.
Nice one Lardo happy soldering.
Regards.
Moggy.
Serious face, when you hinted that you 're going to assemble this little beauty my heart sung, no display cabinet for this one build it and use it.
Nice one Lardo happy soldering.
Regards.
Moggy.
???????????????????????????PIINKEY$?????RND????????????????????????????????????????????????????????PI????????
Re: "Different" ZX81's
Build it.... would be a shame.to.let it rot unused 
I had a kit once.....
I had a kit once.....
what's that Smell.... smells like fresh flux and solder fumes...