Re: sys/dev/isa/fd.c FDUNIT/FDTYPE

[Tom Spindler <dogcow%babymeat.com@localhost>]

Increasingly offtopic, but...

>      That must have been fun.  As I recall, this was basically the
> Apple ][ disk controller squished into one chip. It was hard to call
> that thing a disk controller since it wasn't much more then a TTL
> driver and a shift register.

And a state machine as provided by one of the PROMs. A terribly complete
analysis can be found in "Understanding the Apple II" by James F Sather.

>      My first experience with "operating systems" was basically taking
> a printout of a disassembly of Apple DOS 3.3, figuring out how it
> works, and documenting the entire thing, then mangling it to do various
> tricks.  I wonder where that printout is?  I probably still have it
> somewhere.

"Beneath Apple DOS", by Worth and Lechner, is probably a good alternative.

Both of the books I mentioned appear to be up on scribd these days.