I wasn't able to find a thread for System 7 on unsupported non-Mini hardware, and I learned that it was possible with the CHRP-derived ROM and Enabler via this thread, so I hope this is the right place to share test results for getting something earlier than 9.2.2 running natively on a G4 Quicksilver 2002.
I've started to test out
Mac.OS.ROM_10.2.1_patched.bin and
System.Enabler.356_patched_71x.bin (because I wanted to see the patched boot screen) on my Power Mac G4 Quicksilver 2002 (1x933MHz, 1.5G RAM) with Mac OS 7.6.1 and I've found the following Control Panels and Extensions that need to be disabled for it to boot and run without crashing.
- If I don't disable the WindowShade extension, clicking inside a Finder window will trigger a broken bomb dialog that sometimes doesn't even get to draw its contents.
- If I don't disable the File Sharing Extension, the system will bomb during the boot process with "Sorry, a system error occurred. \n "File Sharing Extension" \n Illegal instruction".
- If I don't disable the Date & Time control panel, you'll get "Sorry, a system error occurred. \n "Finder" \n error type 10." (I was too lazy to confirm, but I suspect this is a Y2K20 bug.)
(After catching those, I found QuickDraw GX complaining that I should have installed the PowerPC version instead of the 68k version and I popped in the 7.6.1 CD to reinstall that.)
I'll have to see how many of those go away if I prepare the system with SheepShaver instead of Basilisk II. (Something I assumed wouldn't matter since I used the "for any mac" checkbox in the installer.)
(More specifically, to get my IDE-SD adapter bootable with 7.6.1, I installed 7.6.1 in Basilisk II with the for-any-mac checkbox, copied the contents over to a folder on my G4, and then booted the Mac OS 9.2.2 install disc from the restore set so I could be in a position to partition the SD card in a way that would boot the G4 before copying the 7.6.1 contents on, since HD Setup won't partition SD cards in USB adapters and the 7.6.1 installer does a machine ID check if you try to run it under 9.2.2 on the G4.)
Also, while they're not crashes, the sound output doesn't work (unsurprising, given how my currently-in-need-of-diagnosis-and-repair Mac Mini G4 worked with OS9), the Display control panel also won't work with the QS2002, so it's stuck with 640x480 and whatever color depth it defaults to, and running 7.6.1 with
System.Enabler.356_patched_71x.bin shows the old boot splash layered on top of the new one.
Maybe, next time I feel like repeating the tests, I'll try swapping in System Enabler 356_patched_75x76x.bin.