Does anyone have a Chroma 81 attached to a zeddy using a vLA81 ULA?
My rebuilt zeddy (https://www.sinclairzxworld.com/viewtop ... 533#p27533) has a vLA81 and when I connect the Chroma 81 I don’t get a screen output. The Chroma works fine on other zeddies.
I wonder if it is the fact that it is rebuilt that is causing issues or maybe being incompatible with the vLA81? I don’t think I had tried the Chroma with it before as it produces a very nice composite output anyway. This zeddy also has a switchable ROM.
Having seen 3D Monster Maze in colour I fancied a go at it but can’t on this zeddy. Ok, I have ‘one or two’ others but this is my main zeddy.
Chroma 81 and vLA81
-
- Posts: 2169
- Joined: Sat Nov 26, 2016 2:42 am
Chroma 81 and vLA81
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
-
- Posts: 2169
- Joined: Sat Nov 26, 2016 2:42 am
Re: Chroma 81 and vLA81
Bump.
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: Chroma 81 and vLA81
Have you tried swapping the vLA81 for a real ULA in that ZX81? That would prove whether it is the computer itself or the vLA81.
-
- Posts: 2169
- Joined: Sat Nov 26, 2016 2:42 am
Re: Chroma 81 and vLA81
I tried another ULA and it still didn’t work so I guess its the computer. To be fair it is the one I rebuilt from scratch!
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
- 1024MAK
- Posts: 5118
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Chroma 81 and vLA81
Test the connections between the edge connector contacts and the destination of each circuit (e.g. to the Z80)...
Mark
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.