Sinclair ZX80 / ZX81 / Z88 Forums

Crayon21 wrote: ↑Tue Nov 16, 2021 5:21 am Max. our previous cat was murdered by the neighbors dog. I've yet to find it and kill it pulled through the fence and eaten.

Oh dear. Maybe you need a bigger cat.


This is not my cat, I wish it was.

Crayon21 wrote: ↑Tue Nov 16, 2021 3:48 am I would submit more if able but i have my kitten to look after.

You can't fool me, I have two cats. They look after me at least as much as I look after them! The younger one especially comes over and curls up next to me whenever I have a headache or don't feel well.

I've tried to open both the small window and full screen versions on a Macbook Pro M1 Max running macOS Monterey 12.0.1. After I get past the usual trust unknown source warnings it crashes immediately for the full screen. I can see it try to occupy the full screen but it flashes black and crashes. ...

I don't understand this game. Is there documentation?

ULAs can and do fail, mostly due to running to hot, or someone plugging the power adapter into the wrong plug port. Old EPROMs can also drop bits, but are usually pretty reliable and can often be erased and reprogrammed. The Z80 CPU can also fail. Erm, actually edge-connector abuse is more likely t...

Re: ULA, interesting and fair do's, I stand corrected (my default stance as you know full well! :lol: ). Glad it is likely reliable. As to the bit rot... Superbrains are well known for this. I'd forgotten about that. So I guess next step will be to see if the ROM has anything in it. Out with the pr...

1024MAK wrote: ↑Thu Nov 04, 2021 1:17 am Please don’t assume that all modern TVs don’t work. I use a Sharp LCD TV with my 1980s computers including ZX81s with RF UHF outputs.

Mark

I have the 210E version of the ULA and it works fine with my 65 inch flat screen TV.

mrtinb wrote: ↑Tue Nov 02, 2021 10:18 pm That requires the Chroma 81 interface, but that is unavailable for order at the moment.

http://www.fruitcake.plus.com/Sinclair/ ... erface.htm

Or there are some circuit mods with transistors, etc, to do B&W composite video output.

doperst wrote: ↑Sun Oct 24, 2021 5:05 am Hello,
unfortunately, the link is dead.

I am new here, about a month ago i started recovering and upgrading my ZX81, now i am collecting as much info on it as possible.

Yup, this link...

It's dead Jim.

This comes in two flavors: A full basic listing and a Machine code variant (which i will get to eventually). The idea came about because there is no way for one unfamiliar with machine code to draw on screen (we don't use lightpens or graph paper anymore so you see the issue). This program asks for...