Sinclair ZX80 / ZX81 / Z88 Forums

I just need enough room for my MMC bootstrap code. Anything else is a bonus.. If I can get to a file on the card then I don't need to hard-code the menu system/dos into the ROM. And if my DMA project gets off the ground I won't need any hacks.. 1 button click to load the bootstrap code, the next to ...

Any tips for hacking the '81 ROM?

I'm thinking of patching the existing ROM for my main hack machine. I'll be removing the printer routines, most likely. Has anyone done this?

Hiya

Nice pix!

I'd be very surprised if there was anything at all high-tech in the printer! My guess would be that the carbon is a residue from the burny-sparky(tm) mechanism...

Good luck with the fix

Will you be planning any cards to fit in this? Just the barest of boards would be good.. Otherwise we'll have to be off to olimex for their overpriced ISA slot protoboards ;) Like I said before, a pre-cooked IO address decoder circuit space, the rest as proto area.. (That is if you haven't been put ...

Hmm. Large enough for 40-pin DILs, certainly. 8255s will be common additions..!

It would be nice to have the pins labelled. Maybe a small section (SMT parts?) for a common IO port decode circuit... Or design a new super one which offers flexibility?

Oh and the moon. On a stick, preferably

@yerz - Having a male conn. on the board would be difficult to arrange - the expansions would have to lie on top of each other.

This 'plane would be for a set of home-made boards. It would be most valuable if there was a basic 'experimenter' plug-in available..! Hint, hint

Sorry I misunderstood

That is a very fine machine that kweeky has..!

I am ashamed to report that I am English and therefore have no gift for foreign tongues..

I'll babelfish the text later. But right now it's food preparation time. Mmmm Food!

In the zx81 options there's a dropdown to enable varioous forms of hrg - one of these is memotech. This is separate from the CHR$ generator.

There's definitely code in there to enable the funky rom overlay that the board provides - I think you need to look again, Xav!

I don't think Mike would mind - the code is open, after all! Mike?

I'll gladly help pointing you at the necessary parts.

You could check the source for Eightyone...