Re: 3.5 " vs. 4.25" Floppy Drive

[Wayne Stewart <waynes@intergate.bc.ca>]

"ruud.dingemans" wrote:

> Still wonderin' what the difference is between a Unidisk and an external
> Mac 3.5 inch drive (I've tried
> several of these and they all work on my IIgs).

In the 800k size Apple put out 3 different drives.
They all use the same 800k mechanisms but there are other hardware
differences.
The 3.5" UniDisk (model #A2M2053) has a small computer controlled
by a 6502 processor inside it. The purpose is to control the drive and
feed the data to the computer at a speed a 1mhz Apple II can accept.
In appearance the drive is bone white(may be yellowed by ultraviolet)
with the manual eject hole underneath the eject button. It also has a
daisychain port at the rear. This drive will work with a IIc, IIgs, a
UniDisk(Liron) card or a SuperDrive card and some UDC cards.
It won't work with a Mac

The platinum 800k dive(model #A9M0106) is controlled by the
computer or card it's attached to. It has a daisychain board that allows
it to work on a Mac or IIgs. In appearance it's characterized by the
platinum colour and the manual eject hole is in the center of the eject
button and it has a daisychain port.. It'll work with a IIgs, IIc+,
SuperDrive card, UDC card or with a Mac. It won't work with a IIc.

The Mac 800k drive(model #M0131) has no eject button or daisychain
port though it does have a manual eject hole. It's a bit slimmer than the
other 800k drives and can be found in beige or platinum colour. This
drive will only work with a Mac or a UDC card.

    Wayne