Sinclair ZX80 / ZX81 / Z88 Forums

You don't need this on a Spectrum - a Spectrum you can just wire the input directly (though some add a capacitor). The board compensates for a shortcoming in the signal from the ZX81 ULA, the Spectrum puts the signal through a video encoder (LM1889).

The Spectrum is indeed much easier - see the full instructions on:

http://womblesretrorepairshack.blogspot ... o-mod.html

The manual / fitting instructions for the ZXvid (if you are using Option A or Option B) appears at:

http://www.rwapsoftware.co.uk/DOC/ZXvid_Manual.pdf

Feedback is welcome

I sent my ZX81 to install ZXVid.

Perfect work and results!

For picky people like me I can say that my ZX81 seems unopened and untouched.

Thank you.

Any reason this wouldn't work on a TS 1500?

Hey Mr SirMorris.... have you a ZXvid knocking around.... want to see if it will work with the TS1500,

i dunno what will happen becaus teh TS1500 already has a back porch....

Andy

I have one installed in my main zeddy. Very nice it is too. Like you say, why add a back porch to a signal that already has a back porch? Are you only after some cleaning up?


C

You could as well have a look here:
http://forum.tlienhard.com/phpBB3/viewt ... =651#p4958
It's a little pcb fitting into the Modulator replacing the internals, or can also be added beside the modulator. As the underside is flat without anything solder on it this can be easily glued wherever you need it.
It digitizes the signal, can be adjusted to the signal level of the ULA, adds a backporch only if needed. Eliminating this noise thats comming from the ULA.
Is just beeing produced and will be available shortly. We are going to present it on our meeting. In SMD if possible, otherwise we will see the prototype.
This can be used on any B&W video signal.

Paul wrote:In SMD if possible, otherwise we will see the prototype.
This can be used on any B&W video signal.

Ähmm - have to correct you.
In general it can be used with any (poor) digital 2-color B&W signal (no grey colors supported to be more detailed) but it is useable only with a video signal with a modulated DC voltage like output of the ULA. It is good for use with direct (or "transistor coupled") ULA output from ZX80 or ZX81 I think.
Other systems not tested.

I'd like a few of these - 3 or perhaps 4. Will there be some available at Mahlerts??