Hi!
As from the title, I’ve got an untested ZX81 at an ebay auction and I get this boot up screen?
What can be the culprit?
In the next days I’ll be able to measure with an oscilloscope the ICs, ma my thanks in advance!
Bought untested ZX81 and got a black screen with a working cursor
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- Joined: Tue Jul 04, 2017 12:12 am
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Re: Bought untested ZX81 and got a black screen with a working cursor
All the chips are socketed by the looks of it - if you have another zeddy try chip swapping to see if that helps.
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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- Posts: 18
- Joined: Tue Jul 04, 2017 12:12 am
Re: Bought untested ZX81 and got a black screen with a working cursor
I don't have it, but I've bought a ULA - I think is the culprit - and when I'll get it I'll update the thread!
Re: Bought untested ZX81 and got a black screen with a working cursor
Is it possible that there is a composite conversion in it that needs pot adjustment? Maybe look under "RF Modulator" and see which circuit is in there.
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