Sinclair ZX80 / ZX81 / Z88 Forums

The issue with passing parameters is the interface to BASIC. It's not as ASM friendly as our Acornic cousins ;) Ah I see now, and of course unlike the Spectrum there are no in and out functions built into basic so you can't even read the port directly. I've had a thought how I can add some semblanc...

That's how I'll be doing it. .org 8190 jr realReadJS Getting a value quickly into a register isn't that easy on the '81. There could be a poke but that's a bit scuzzy so a dispatcher won't happen on my watch. Excellent. Dunno Z80 that well, having dabbled a little, some 25+ years ago (when the ZX81...

Excellent so they are active low with pullups :) :) Can I make a sugestion if you are going to have many rom calls (sorry you already know or are indeed doing this :)) but use a scheme where the location called will remain the same across firmware upgrades so something like a jump table org some_fix...

Hi Andy, I'm looking to try and convert your PAL design to a single CPLD (after prompting by SirMorris) and a few descretes, but as usual I'm fine with the digital stuff but fall down when it comes to things like transistors..... Could you do me a favor and double check the two transistor oscilator ...