fair point that was worth trying, I tried on another TV and it was a little different.
Either.. A few times I got a very steady black screen (No cursor etc, just black)
the other times I got crazy noises and patterns like in the video
Hello All & Dead ZX .. probably
- 1024MAK
- Posts: 5171
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Hello All & Dead ZX .. probably
Modern TVs, if they can’t detect the back porch part of the video signal, they get their auto calibration of the black video level wrong. This results in a very dark image even with the brightness and contrast turned up to full or nearly full.
Mark
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: 15
- Joined: Mon Mar 04, 2019 5:33 pm
Re: Hello All & Dead ZX .. probably
Oh well, I tried first the CCB because it was the least disruptive, which didnt work, followed by a new ULA, which also results in the same video signal. I guess now the only thing left to do is replace the other chips!
-
- Posts: 15
- Joined: Mon Mar 04, 2019 5:33 pm
Re: Hello All & Dead ZX .. probably
Ok I was wrong, the new ULA does work!! Keyboard is a bit iffy, but for now, I'm happy!
- 1024MAK
- Posts: 5171
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Hello All & Dead ZX .. probably
Good to hear that you are up and running (well, once you have sorted the keyboard)
Mark
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.
Re: Hello All & Dead ZX .. probably
i had a commodore pet universal main board ( from a cbm 4032 machine) in the kitchen sink... my missus thought i'd gone nuts... works a treat and is clean to boot now
what's that Smell.... smells like fresh flux and solder fumes...