Zx81 composite mod with backporch-Advice

[rmbrowngr]

Looking for advice on which composite mod with backporch to buy as ZX8-CCB and zxvid are not available.

I can do basic soldering tasks. And I just received a wonderful zxpand+.

[Paul]

ZX8-CCB should be available next week.
It's definitely the best choice.
Have you tried https://www.ginger-electronic.com/de/re ... -zx81.html

[Lardo Boffin]

+1 for ZX8-CCB. I have fitted more of these than I can count! The first ZX81 job I ever did was to fit one of these.

They are showing as a available:

https://www.ginger-electronic.com/en/re ... -zx81.html


Some musings on the two options along with some photos showing fitting on page 3 onwards.

https://sinclairzxworld.com/viewtopic.p ... 765#p21765

[Lardo Boffin]

You may need to adjust the two pots in order to get a good picture on the TV you wish to use.

Best advice for this is to take a photo on your phone of the pots before adjusting so you can revert if necessary.

This is my default start point after fitting numerous of these:

Depending on your ULA you may get a picture straight away and not need to adjust anything.

[Lardo Boffin]

I would also get a KDLX keyboard at the same time. Much better than a standard flat membrane.

[rmbrowngr]

ZX8-CCB should be available next week.
It's definitely the best choice.
Have you tried https://www.ginger-electronic.com/de/re ... -zx81.html

I took a look at this, in the English version of this page (https://www.ginger-electronic.com/en/re ... -zx81.html), but I don't see it mentioning about the back porch. I Definately need this feature.

Let me know when you have your ZX8-CCB if it addresses the back porch issue.

[Paul]

It adds the back porch.

[rmbrowngr]

I would also get a KDLX keyboard at the same time. Much better than a standard flat membrane.

Yes, I'm interested in this too. BTW, the fitting instructions are a bit unclear if you remove the old keyboard \ membrane, as the site shows the cables sticking out of the case.

I've also seen you post viewtopic.php?p=48624#p48624 on how you modify your ZX81's. Is it worth while replacing the voltage regulator and capacitors? If so, does someone sells this as a kit?

[Lardo Boffin]

You can get the capacitors here:

https://www.retroleum.co.uk/zx81-components

And the voltage regulators here:

https://www.retroleum.co.uk/spectrum-repairs-mods


Its the murata regulator at the end of the list. Order quickly as they tend to vanish (but are posted often).

The capacitors are not essential but the regulator really helps keep your zeddy cool.

[Lardo Boffin]

You can apparently leave the original keyboard membrane in place if you wish.

I never have, I always remove them first. A hair dryer is very useful for the removal of old keyboards. It part melts the glue so they come off easily.

You will need some strong double sided tape for the KDLX. I use this stuff:

https://www.ebay.co.uk/itm/154340327039 ... media=COPY