[Coco] Software testing for FDC emulator

[Aaron Wolfe]

> ...You can call them subdrives or virtual drives but they
> behave just like the FDC...

I think it's important to reiterate that CoCoNet/DrivePak/etc drives
do not behave exactly like a FDC.  They are actually incompatible with
lots of software, mostly games.  DriveWire has this same limitation,
and I suspect most IDE/SCSI controllers do too, so it isn't picking on
CoCoNet, but I know from discussion in the IRC channel it is has been
a common surprise to a new user of the serial based systems that they
might not be able to play their favorite game after all.

Darren's project fixes this, hopefully providing 100% compatibility
with all software.  Also, any OS9 software should work fine with
coconet and other alternatives.  But, to say your system behaves just
like the FDC can lead to disappointment, as I have seen first hand.  I
am now careful to explain the limitations of serial based drive
systems when talking with people about it.

-Aaron