#2 Diagnose beep codes on boot

[SD Snatcher]

Please implement diagnose beep codes like the most PC-BIOS have.

http://networking.ringofsaturn.com/PC/beep.php

This can help to diagnose problems that occur on boot. The standard MSX BIOS has nothing like that, leaving the users on dark when any component of the MSX is defective (RAM, PPI, VDP, etc)

[Maarten ter Huurne]

I think that in every case except broken VDP or broken VRAM, we can put a message on the screen instead of beeping. This would save users from having to look up the beep codes. There is already code that prints "MEMORY NOT FOUND." if the search for RAM does not find anything.

There is no diagnostic code for the PPI, PSG, VDP, VRAM etc yet as far as I know. It would be a lot of work to thoroughly test a chip, but simply checking whether a written value can be read back would already detect most broken chips probably.

I don't know whether the current version of C-BIOS can actually run on real hardware. I know someone tried with an early version and that didn't work because the VDP was written too fast. It would be useful if this test could be repeated with today's C-BIOS.

[SD Snatcher]

Ok, I do agree about the VDP/broken RAM being the only case that needs beep-codes.

I just tested the C-BIOS v0.24 on an Expert 1.1 (VDP=TMS9128, PPI=NEC8255, PSG=A-Y-3-8910A, RAM on slot 2 unexpanded) and it didn't booted at all. No image is shown, and this is why I asked it to issue some kind of beep codes. Any troubleshooting information is useul on real hardware. :)

[SD Snatcher]

I decided to give C-BIOS a try on my Sony HB-F1XDJ (512KB RAM). Unfortunately, it didn't boot also. No reaction at all...