I thought I had already pointed out your design in your signature.1024MAK wrote: ↑Sat Jun 13, 2020 8:29 pm ZX81 Video Transistor Buffer Amp
There is also a design using a NE555 timer chip to generate a pulse for the back porch. I’m not tried it. Alternatively, there is the ZXVid.
Mark
Lardo buys another zeddy
Re: Lardo buys another zeddy
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- Posts: 2191
- Joined: Sat Nov 26, 2016 2:42 am
Re: Lardo buys another zeddy
I popped the case and it is very shiny!
ULA 2C210E.
ULA 2C210E.
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: 5165
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Lardo buys another zeddy
You had, but I thought it worthwhile copying said link into a post so that it was crystal clear
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: 2191
- Joined: Sat Nov 26, 2016 2:42 am
Re: Lardo buys another zeddy
I have adjusted the pot in the modulator and it helps but not enough. Guess I may have to try a transistor mod!
The ZXVid is great but a bit expensive to be able to then sell this on.
The ZXVid is great but a bit expensive to be able to then sell this on.
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: Lardo buys another zeddy
Do it lardo you know you want to.
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- Posts: 2191
- Joined: Sat Nov 26, 2016 2:42 am
Re: Lardo buys another zeddy
I have a plan! It involves a weasel.
Or at least stealing the ZX8-CCB from my test rig and putting it in this zeddy and then making one of the comp mods shown and putting it in my test rig.
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: Lardo buys another zeddy
God that's a cunning plan if ever I heard one!
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- Posts: 2191
- Joined: Sat Nov 26, 2016 2:42 am
Re: Lardo buys another zeddy
And done!
I had cut the cables a bit shorter to fit inside my test rig so was faced with a dilemma - fit new cables (eyesight issues with that) or not fit it where I would normally fit.
So I went with option 2.
There are no clearance issues and the red and black cables are fine when routed properly. The board (yes its a green one, thats how old my test rig is / was!) is held by a very strong piece of double sided foam.
Any chance of interference from the PCB? The picture seems rock solid so far.
I also noticed this once I opened the case:
Where is the solder holding the modulator in place?
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: 5165
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Lardo buys another zeddy
You should write to Sinclair and ask them?
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: Lardo buys another zeddy
No need for that.
I happen to know that at the time when most companies were turning to lead free solder Timex decided on a more rigorous strategy of using solder free solder and as you can see it works wonderfully.
Having drunk more whisky than usual so early Moggy retires to his settee for a long nap.