Lardo buys another zeddy

ZX80 / ZX81 hardware and software offered for sale or swapping
Moggy
Posts: 2040
Joined: Wed Jun 18, 2008 2:00 pm

Re: Lardo buys another zeddy

Post by Moggy »

1024MAK wrote:
Sat Jun 13, 2020 8:29 pm
:arrow: 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
I thought I had already pointed out your design in your signature. :?

Lardo Boffin
Posts: 1234
Joined: Sat Nov 26, 2016 2:42 am

Re: Lardo buys another zeddy

Post by Lardo Boffin »

I popped the case and it is very shiny!

E4174CF7-0D14-4099-9447-1C4E5BB0A0A2.jpeg
ULA 2C210E.
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
Iss 3 ZXVid
TS 1000 iss 3, ZXPand AY, ZX8-CCB, ZX-KDLX & ChromaSCART
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Spectrum +2a

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1024MAK
Posts: 3032
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Lardo buys another zeddy

Post by 1024MAK »

Moggy wrote:
Sat Jun 13, 2020 10:42 pm
I thought I had already pointed out your design in your signature. :?
You had, but I thought it worthwhile copying said link into a post so that it was crystal clear :mrgreen:

Mark

Lardo Boffin
Posts: 1234
Joined: Sat Nov 26, 2016 2:42 am

Re: Lardo buys another zeddy

Post by Lardo Boffin »

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.
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
Iss 3 ZXVid
TS 1000 iss 3, ZXPand AY, ZX8-CCB, ZX-KDLX & ChromaSCART
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Spectrum +2a

Moggy
Posts: 2040
Joined: Wed Jun 18, 2008 2:00 pm

Re: Lardo buys another zeddy

Post by Moggy »

Do it lardo you know you want to. :lol:

Lardo Boffin
Posts: 1234
Joined: Sat Nov 26, 2016 2:42 am

Re: Lardo buys another zeddy

Post by Lardo Boffin »

Moggy wrote:
Sun Jun 14, 2020 2:12 pm
Do it lardo you know you want to. :lol:
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)
Iss 3 ZXVid
TS 1000 iss 3, ZXPand AY, ZX8-CCB, ZX-KDLX & ChromaSCART
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Spectrum +2a

Moggy
Posts: 2040
Joined: Wed Jun 18, 2008 2:00 pm

Re: Lardo buys another zeddy

Post by Moggy »

God that's a cunning plan if ever I heard one! :lol:

Lardo Boffin
Posts: 1234
Joined: Sat Nov 26, 2016 2:42 am

Re: Lardo buys another zeddy

Post by Lardo Boffin »

Moggy wrote:
Sun Jun 14, 2020 6:38 pm
God that's a cunning plan if ever I heard one! :lol:
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.

1B193437-51C4-4D08-9FED-C90A0DC6C65B.jpeg

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:

80C8F137-AB11-42C2-9E7F-799D0D4C4F95.jpeg

Where is the solder holding the modulator in place? :shock:
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
Iss 3 ZXVid
TS 1000 iss 3, ZXPand AY, ZX8-CCB, ZX-KDLX & ChromaSCART
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Spectrum +2a

User avatar
1024MAK
Posts: 3032
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Lardo buys another zeddy

Post by 1024MAK »

Lardo Boffin wrote:
Mon Jun 15, 2020 12:00 am
Where is the solder holding the modulator in place? :shock:
You should write to Sinclair and ask them? :lol:

Mark

Moggy
Posts: 2040
Joined: Wed Jun 18, 2008 2:00 pm

Re: Lardo buys another zeddy

Post by Moggy »

1024MAK wrote:
Mon Jun 15, 2020 9:33 am
Lardo Boffin wrote:
Mon Jun 15, 2020 12:00 am
Where is the solder holding the modulator in place? :shock:
You should write to Sinclair and ask them? :lol:

Mark
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.

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