A Sharp SP-5025 BASIC program listing, using an accurate homemade replica font in a linux terminal.

This is making me happy today - I've made good progress on listing and printing the contents of Sharp #BASIC programs using a homemade authentic-looking font.

#PicoMZ80K #PicoMZ80A #RetroComputing

z80.timholyoake.uk/displaying-s...

Pico MZ-80A announcing SA5510 BASIC has loaded correctly

A game of duck shoot in progress. You beast!

More progress - A/K VRAM modes appear to work ok and it's happy enough with SA5510 and a game of duck shoot 😱

#RetroComputing #PicoMZ80A

A little bit of progress today ... Keyboard handling is now mostly sorted. Next job is probably to look at the additional 0xE0nn addresses that the #MZ80A uses for various things, including reverse video and screen / VRAM scrolling.

#RetroComputing #PicoMZ80K #PicoMZ80A

SA-1510 monitor start without lots of smiley faces.

That's better!

#RetroComputing #PicoMZ80A #PicoMZ80K

The explanation of what's happening from the Sharp Users Club Sofware Manual III "The effects are disconcerting to say the least"

Should be easy enough to craft a fix, as I know where the program counter is when the vga display routines are called. I think!

#RetroComputing #PicoMZ80A #PicoMZ80K

It's most noticeable (at the moment) during emulator startup as the monitor is attempting to clear the screen by scrolling it downwards (Sharp ASCII 104). But my emulator assumes you are 'poking' 104 (0xCF) ... which happens to be a face in the Sharp display codes.

#RetroComputing #PicoMZ80A

The MZ-80A emulator at boot. As well as the SA-1510 monitor prompt, the screen is full of green faces due to a feature of the monitor code.

Here's an interesting "feature" of the MZ-80A monitor ROM. Depending on whether the screen is addressed by the monitor or 'poked' to from BASIC, some ASCII codes have a different effect.

#RetroComputing #PicoMZ80K #PicoMZ80A