I always had Macs as a kid. I used to hang out on the 68kMLA forum when I was in high school. Now I do Linux driver development for 5G telecommunications SoCs. I recently bought a Mac Mini G4 to show my kids some of what I used to play with (after a clamshell iBook started to fall apart faster than I could fix it). It’s amazing what folks here have done to get Mac OS 9 to run on this hardware.
Anyways, it’s frustrating AF that onboard audio does not work quite right with Mac OS 9, and I was wondering if this is something I could fix.
Resources I’ve found on this:
https://github.com/torvalds/linux/tree/master/sound/aoa — this is the Linux kernel driver for this sound hardware (Toonie in our case). It looks like there is no hardware support for setting the volume — it’s just a DAC — so any system-wide volume control would have to take place in software.
https://vintageapple.org/inside_r/pdf/Sound_1994.pdf — chapter 6 shows how to build an audio component, and what capabilities and callbacks are exposed through one.
http://macos9lives.com/smforum/index.php/topic,4682.msg36250.html — this shows which built-in component is used for the Mac Mini’s audio, and gives some basic information on how to find that within the System file.
So as far as a basic plan of attack, here’s what I’m thinking:
(1) Figure out how to extract the existing ‘awgc’ audio component from the Mac OS 9.2.2 system file (would
https://github.com/fuzziqersoftware/resource_dasm be the right way to do this?)
(2) Reverse-engineer it to figure out what’s going on currently. (Would Ghidra work, or do people have a tool they like better for classic Mac OS stuff?)
(3) Modify the audio component and put it back in the system file.
Would this be a sane way to go about it? Has anyone else worked on this and has more information to contribute?
Thanks!