Home Page Forums Other Emulator Message Boards Modeler and M1 Any future updates to M1?

Ok, thank you.

Apologies if this question is stupid... If SDL is used (on a Mac) won't it talk directly to the sound hardware via Core Audio, so the SDL routines on their own should be sufficient? The point I'm trying to make is: can I just take the oss.cpp file and remove most of the code apart from the SDL-specific routines and that should get me fairly close to a working solution?

In theory, but the SDL routines there almost certainly aren't for SDL 2.x as far as I remember (I'm not sure 2.x *existed* at that time) so they won't build against current SDL 2.30 (or the 3.0 preview).

Basically what I'm saying is that the source drop you found is self-service. That was true in 2010 when I still remembered any of it, but it's way more true 14 years later.

Ok, understood and thank you again for your help - I appreciate you are busy with new projects and M1 was a very long time ago. I did think SDL 2 would be too recent, and using SDL 1 probably won't work on the later OSs so I will have to rewrite the SDL routines.

If I make any meaningful progress I will post here again. If any Mac users are interested in working on this please PM me.

Update: I've managed to get the command line version built and working, sort of:



I've tested with Hot Chase, Cyberbots, Aggressors of Dark Kombat and Godzilla (pinball machine) so far and only the first songs as the key commands don't appear to be working, but I definitely hear some sound! I had to comment-out some code in roms.c that was causing an illegal hardware instruction error, and also remove the reference to the lasound library in the make file before it would build. I only have SDL 2 on my machine but this doesn't seem to be an issue. Using pulseaudio didn't work even though I have the library installed, so I'll stick with SDL for the moment.

Batman - Revenge of the Joker (Genesis game) gives me a segmentation fault. The fm2612.c file does not appear to be being included in the build, so I'll ignore these games for the moment as I presume it's related to this file.

I've identified the cause of the segfaulting on the Genesis games, which is due to the YM2151 driver code when run on a 64-bit system (I think). This also affects Atari System 1 boards and various other games. It appears that the key code (KC) channel/register needs to be initialized when the chip is started/reset - I found this out by looking at the MAME 0.100 source code.

In the M1 code, open sound/ym2151.c and find the YM2151ResetChip function, then where you have this line

chip->oper[i].volume = MAX_ATT_INDEX;

immediately after it add

chip->oper[i].kc_i = 768; /* min kc_i value */

Hope that helps someone. I do not claim to understand anything about the YM2151 chip, I just copied-and-pasted the code.