Sharp MZ

Have a look at https://en.wikipedia.org/wiki/Intel_8255#Bit_Set/Reset_(BSR)_mode. When you write at $E002 (Port C), it is not the same as reading at the same port. I don't understand how setting 0 to this port will set PC1 to 1 (should be $03 instead). I don't understand your code because of that an...

So trying to emit bytes as the Monitor is expected to read them instead of saving them solves the issue as far as I can see. I had also a working state machine version. I made some changes to add an ultrafast mode but it probably broke that version. So I must wait for the next weekend to fix it. I t...

As for MZ-80 A, the commands are different and probably the same as MZ-700: press [ B ] then [CR] to toggle key beeping.

Tried SG but no sound, nor out of my fully working 80A either. Perhaps I am doing it wrong? Is it SG then [Return] or just SG? You must type [S] then [G] then [CR] (what you call 'return') just after powering the MZ-80 K. If you cannot hear any beep after pressing keys, so your monitor is not runni...

Would not it be related to the arduino UNO? On MEGA2560 I do not have that kind of problem. FR: Je travaille en ce moment sur la piste en question. J'ai aussi commencé à réfléchir sur le pourquoi tu n'as peut-être pas le problème : tandis que je procède de la même manière que fait le monitor pour s...

FR: non, je suis sur MEGA aussi. En fait, l'explication se trouve dans le fait que la librairie SdFat enclenche des interruptions probablement lié à un "look-ahead" qui viennent pertuber le temps passé entre la sortie de la boucle d'attente qui maintient le signal à 1 et la mise à 0 du sig...

Looks as if your VRAM contains a repeated sequence of $3A $00 $3C $00 or $3A $00 $3C $FF or $3A $FF $3C $00 or $3A $FF $3C $FF. Those characters are valid in the display table. Was the burned MROM checked to run on a working MZ-80 K before you got it? Is there any indication the monitor is working? ...

Is the source accessible anywhere? I want to see if I can help you to build a text game engine with scripts you can write instead of using a BASIC. That way, you'll get a pure binary that you can load on any MZ-80 K compatible computer.

FR: Pour revenir au problème que j'ai. J'ai écris un programme que je charge d'abord dans la page vidéo non-affichée du MZ-700. Ce programme me permet de calculer le checksum du dernier programme chargé (et je l'ai par la suite modifié pour qu'il m'affiche des checksums partiels tous les 256 octets ...

A lot of manuals here but not the one you're looking for: https://www.manualslib.com/brand/sharp/desktop.html