Sinclair ZX80 / ZX81 / Z88 Forums

you might need special code for ZX-PC transfer, but the keyboard itself will just work...

Mike

XavSnap wrote:

http://www.user.dccnet.com/wrigter/inde ... XKBDv3.htm

seem great...
But, you had to twick the ROM or use a software driver !

No you don't... just plug it into the expansion port and start typing.

Mike

All timing in a TZX file should be relative to a 3.5MHz clock.

I have a #define in my TZX file code:

#define TZXSCALE(x) (((float)x)/(((float)3500000)/((float)machine.clockspeed)))

Then when I load a file in, all values are put through scaling.

Mike

Hi Andy. It's a great start to an emulator. Now all you need to do is the boring stuff... loading/saving, peripherals etc. I wouldn't worry to much about multi-threading - EO isn't multi-threaded either, though I did once consider it and there's some threading code commented out in the source. On th...

Hi Andy. Here's the programs I used fairly regularly to get EO reasonably correct: http://www.chuntey.com/testsuit.zip You've done most of them, but I noticed you haven't tried Xtricator. It uses a completely different pseudo-hires routine to most programs. The Z80s IM2 mode is used to redirect the ...

Given an address in memory, it's trivial to disassemble the instruction at that address, know it's length in bytes, then move onto the next instruction. However, how would one know what the immediately previous instruction was before that address? It would be easy if all instructions were the same l...

sirmorris wrote:Could anyone produce a memotech work-alike? Even just the schematic would be great. Perhaps we could even do a small production run?

I believe Wilf has at least two projects that would suit you

http://www.user.dccnet.com/wrigter/ of course.

Mike

Then it could work, if You're right the Speccy boxes should work also with Zeddy. I know the Kempston interface works on the ZX81 - I've tried it. However, as I said the kempston is the hardest to read on the '81 due it not simulating keypresses but using port 31. An AGF/Protek (Cursor key) interfa...

is posible to emulate the keystrokes from the expansion port ? I mean without any software part ? Yes. There were several replacement keyboards for the ZX81 that plugged into the expansion port. The simplest joystick interface to make would be similar to the Spectrums IF2 - using keys 1,2,3,4,5 or ...

yerzmyey, EO plays AY fine* on both XP and Vista here. However, I did find a couple of bugs with OUTD/OUTIR instruction which stopped *some* AY tunes playing. If no AY music at all is working, then there must be another problem somewhere. It's strange though. If beeper sound works but not AY, the pr...