Tim HolyoakeHere we go again ...
Just been searching out MZ700 monitor & graphics ROMs. Bitrot has set in on many trusted Sharp MZ resources, so only spammy download sites now claim to have them. Fortunately I'd downloaded the ROMs a couple of years ago, but it seems like a race against time to preserve what's left. #RetroComputing
It's a start! Hacked the monitor into my mz80k/a code and it runs up. Now comes the painstaking stuff - keyboard mappings, colour, clock accuracy etc etc etc ... #RetroComputing #Sharp #MZ700
A nice bit of Saturday afternoon progress on the Pico #MZ700 emulator. Colour output has been working for some time and I now have a reasonable USB to MZ700 keyboard mapping sorted as well.
Next up - I need to sort out timings (can this really emulate a 3.5MHz MZ700 on a Pico, or will a Pico2 be required) and the banked memory implementation. This is, of course, a completely different implementation to that used on the MZ-80A.
#Sharp were nothing but (in)consistent with the MZ series machines!
Sorted out the display of the upper 256 characters today. Took longer to figure out than it should have ...
I seem to be getting close to having a reasonable #M700 #emulator running. There are some oddities that I need to look into (e.g. keyboard handling for monitor in ROM seems different to monitor in RAM) and I need to retrieve my real MZ-700 to check various timings.
I think I may have found the weirdness in the keyboard handling today. Looks like I may need to rewrite my 8255 emulation as it could also be the root cause of my cursor blink speed issues. More investigation needed however. #RetroComputing #Sharp #MZ700 #PicoMZ
My rewrite of the 8255 emulation seems to have fixed the keyboard handling weirdness and cursor blink speed issues on the #MZ700 emulation. It also seems to have sorted the odd glitch I knew I still had with #MZ80K keyboard handling. The new emulation is more efficient, so I may be able to drop the Pico clock speed another 10MHz or so ...