Sinclair ZX80 / ZX81 / Z88 Forums

There are a few reasons why Andy isn't contactable at this time, personal circumstance being one, and any interest in things concerning Sinclair computers is furthest from his mind at this time I would say.

A rough rule of thumb re manuals are if it's a spiral bound version then it belongs with an issue one board.
For the later issue three boards they tended to have what I call, the normal paper back book spine, again just a rough and ready rule.

I have a silver coloured book called 49 explosive games for the ZX81 but sadly it doesn't contain anything remotely like what you describe for the ZX81. However some ZX80 games are included and there is a ZX80 game called space station which does include the things you describe, IE food allocation r...

1024MAK wrote: ↑Wed Jun 07, 2023 4:12 pm Andy has taken a step back from the scene.

His last post was in June 2021. Although he has logged into the forum earlier this year.

Mark

Having been recently in touch with Andy I can confirm that he won't be returning any time soon if at all.

I thought changing the tyres on Max Verstappen's car was unique but this surpasses that!

I regard this as a most excellent simulation and all in 1K!

Nice one Johan.

Nothing out of the ordinary there apart from the non UK modulator.

Second issue NEC ROM (622), Ferranti second issue ULA (184), NEC CPU and a Mostek 1k RAM chip, I always thought the US computers had a 2k chip fitted but maybe that was just the Timex versions.

I had the dead "keyboard-works-with-Memotech-only" situation, can't say anything about whether tape load/save worked as, thanks to spands various, I haven't used a tape in over ten years and binned all my tapes (sacrilege I know) but everything is available as P file these days so no worries.

Cheers Mark, that's tonight taken care of!

The ZX81 uses a mix of software and limited hardware to create a video picture. The Jupiter Ace video system is based on hardware, it will continue to produce a video image even if the processor is stopped (HALTed) or busy (unlike the Zeddy). Hence 2K bytes of the 3K bytes of RAM in a Jupiter Ace i...

Better still, solder 4 resistors to the right places on the CPU, program an EPROM with the ZX80's ROM code, fit a reset switch across the reset capacitor and have the real thing on a ZX81.