Re: IIe 3.5 disk drive controller card

[Ed Eastman <noone@nowhere.net>]

From my FAQ regarding 3.5" drive usage on an Apple II:

The Apple 3.5" drives all have in common that they have a variable 
rotation rate and can read the 800k 'standard' formatted DD disk media.

Apple Unidisk 3.5" drives have an additional logic board inside of them 
that allow them to be used on the relatively slow Apple IIe with a 
'liron' card and the updated IIc.   These drive also work with but are 
not recommended for use on the IIgs, IIc+ or with the 'superdrive' 
controller as their extra logic is slower than using a regular 3.5" drive.

The regular Apple 3.5" disk drives are 'dumb' and require the computer 
to control the drive directly like the 5.25" drives.  To do so requires 
faster interaction than a standard Apple II can provide.  This drive can 
be used with the IIgs, IIc+ and an Appple II with a 'superdrive' controller.

The Apple 3.5" Superdrive is exactly like the regular 3.5" drives except 
that it can read HD media (1.4M storage) when attached to a 'superdrive' 
controller.  The format of the HD media is usually drive compatible with 
the IBM/Windows world so some data transfer using this device can be 
accomplished.  When the 'superdrive' is hooked to anything other than 
the superdrive controller it will look and act as a regular Apple 3.5" 
(800k) drive.