I've been tinkering around with an Apple II emulator after writing an NES one (they share 6502 processors) and have it reading disk images, displaying graphics, and generally playing whatever games or software I throw at it. One difference I can't explain however has to do with the boot-up sequence and how it interacts with its disk drives.
When the Apple II starts up it finds a disk controller (if installed) and attempts to load any disk it has in the drive. It will happily do this forever, endlessly spinning the motor. If you then hit Reset the system will drop out of this search and into the BASIC prompt. On real Apple hardware that will turn off the disk drive, which will spin down after it's in-built delay. However, my emulator does not turn off the disks, it just happily keeps running them. That's because nothing in the ROM seems to be instructing it to do otherwise. I've traced through its code when a reset occurs and I can't seem to find anything talking to the disk controller either.
I'm curious if anyone knows the details on this. Does the system have some other method to kill the drive motors that's not apparent from the ROM? Or did I just miss something?