Sinclair ZX80 / ZX81 / Z88 Forums

Hello and welcome to our forum sl07h1. :D It's always nice to see new faces from around the world and also nice to know this small computer possibly helped you choose your career. The folk here are nice and friendly and will help with any questions you may have and please do read the many threads on...

Thanks for the explanation about the ZX80 video routine,this makes sense now.

I have found that if I do the opening moves for the opponent and then let it play for itself a good game can be played plus it's nice to have something for the ZX80 to do.

Both the ZX80 and 81 have had a full FIDE 1k chess for about five years now. I did a lot of play testing for Stefano of both versions and whilst the ZX81 version is quite excellent in my opinion, the ZX80 version is problematic from a gameplay point of view which I find surprising as I believe they ...

And you're not leaving until it's fixed!!!

(Or until Lardo sells you one of his Chinese zeddy knock offs)


Moggy hides fearing lardo's wrath

As I said earlier I'm not the smartest here but I have seen similar patterns when the onboard RAM chip(s) were shot. The only way I could test was by using a RAM pack, which cuts out the onboard memory, as for for scoping and probing tests then hopefully a forum guru who knows their way around such ...

Top picture wrong, bottom picture correct re ROM position.

I cannot help further than that I'm afraid as I don't have the Latin for things technical.

The programmer bursts in fractions of a second if memory serves and there is no way you could keep up with that manually I assume.

That's great news Trevor got there in the end.

Most excellent!

Further to the above if you do use an external supply then some method must be used to obtain either 21 or 25 volts. The three batteries put out 27v and in my programmers case a small onboard dropper circuit ( zener diode and resisters I think ) is used for required voltages.