So why the special exotic disk hardware for the
Lisa and Mac?
Because Apple! Duh!
At least they belatedly realized how mind-bogglingly stupid it had been to
make their own floppy drives, and switched to Sony.
Did Apple ever make their own drives? The Disk ][ has many mechanical
parts interchangeable with a nroaml Shugart drive, inclduing that
horrible plastic head posiitioner with the spiral groove. Yes, the
electronics was an Apple design, but the mechanical side looks pure Shugart.
The Sony drives used in the Macs were not standard Sony drives. Sure they
had a lot of parts in common [1] but there were differences,particularly
i nthe electroncis. Much the same situation as the Disk ][
[1] Many of the parts used in the (standard) Sony drive in the HP9114Bare
interchangeable with thos in an Applie 800K drive. The head carriage,
stepper mtoore, etc for example. On the PCB the digital SIC that handles
ti the host interface is of course differnet between the stnadard and
Apple drives, but almost everything else, includign the analogue ASIC
that handles the read/write signals is the saem. The stnadard drive even
has a place to fit an eejct moroe and there are unused component
lcoations on the PCB to fit the motor drive components.
-tony
