Sinclair ZX80 / ZX81 / Z88 Forums

There's one other game doing the rounds that I uploaded to a ZX81 site back in 2000. I was quite amazed to google it and find its on a lot of sites now! That game is called 'Whale Attack' and is a very simple game that survived as a hand written listing. More recently I have retrieved some of my cas...

And it is the klutzed ROM....PRINT SQR .25 returns 1.7xxxxxxx I thnk. Certainly not 0.5.

OK so I had a look today, the RAM pack contains two circuit boards linked by a ribbon cable and says "ISSUE 2" on the first board (the one with the edge connector) On Friday it would run for an estimated 10 seconds. This time I ran it for 4 minutes on three separate occasions without any crashes. BU...

Its definitely two boards linked, I just assumed they were all like that as the one I had 30 years ago was the same (but without the paranoid FCC warnigns)

I'm keeping it at work so I shall open it up again on Monday but I didn't notice any ULA. Everything looked fine, as you said I noticed the silver paint on the inside.

What I shall do on Monday is time the problem accurately, and have a look at all the capacitors...and look for a ULA.

I have not timed it accurately, but I believe it is the same time. It certainly does not vary much. I managed to type the first two lines of the POKE program which returns the total RAM before it crashed. This I did twice. On other occaisons I have just let the machine sit and it crashes, or have tr...

I recently obtained a 16K RAM pack for my ZX81, looks almost brand new. If relevant it is the USA version. Anyway the Zeddy 'boots', taking a second or so to scan the memory before the K cursor appears....then after about 10 seconds the machine crashes. This happens reliably with the RAM pack but no...

Hey guys, I didn't want to open the machine up again but I obtained a RAM pack and was getting very inconsistent connection. So I opened up the Zeddy again to clean the edge connector contacts, and took the opportunity to photograph the motherboard. The ULA is attached directly and just has the numb...

SO my ZX81 is at work still as the Mrs doesn't want me to bring it home...and since its functioning on 1K for the time being I have been using a few Sinclair Programs listings and of course JK Greye Software's "10 games for 1K ZX81". Guillotine (rather like hangman) is proving quite a hit. My collea...

Way back in the early 1980's I wrote some ZX81 games which I considered were pretty good at the time. I intended to offer them for sale but bottled out. Now I am rediscovering some of my old listings and tapes, I'm intending to release most of them on the web as .p files free for distribution. But I...