Mac OS Classic
- What language is OS 9 written in?
- Regarding the ROM...
- Wikipedia article on Mac OS Classic
- Inside Macintosh (on archive.org here
- Macintosh Programmer's Introduction to the Macintosh Family (also here and here and here)
- Vintage Apple's Mac Programming Books
- PowerPC History - in particular, this discusses in some detail the 68k emulator
- "Question from a non-programmer"
- Lowend Mac's article on Pink / Taligent
- On the Sound Design of TalOS (includes a screenshot from a TalOS demo)
- A Technical History of Apple's Operating Systems
Apparently, Mac OS 9 is very popular amongst audio engineers that want to create very low-budget setups.
- An OS 9 odyssey: Why these Mac users won’t abandon 16-year-old software
- ArsTechnica Forums - Research for the above article
- Mac OS 9 Lives