Re: Apple UniDisk 3.5 vs. Apple 3.5

[spec@vax2.concordia.ca (Mitchell Spector)]

In article shack@deimos.frii.com (Randy Shackelford) writes...

>OK I think it's time for the Canonical List o' External Floppies (tm):
> 
>1. beige, Apple logo not in color, notch at right end of disk slot so you 
>   can jam the disk all the way in -> 400K external for Mac, incompatible 
>   with IIs
> 
>2. beige, colored Apple logo, no eject button, no daisychain port on the
>   back -> 800K Mac external, incompatible with IIs

    Both of the above drives (Macintosh 400K and 800K Drive) will work
with an Apple II Plus, IIe and IIgs if connected to a VTech UDC card
(Universal Disk Controller). As well, they should work with Laser 128
models EX and EX/2, which have the equivalent of the UDC built-in.

>3. white, eject button -> unidisk 3.5, compatible with 32K ROM //c and up,
>   //e with "Apple 3.5 floppy disk controller card" AKA the LIRON card,
>   //e with "Apple II 3.5 disk controller card" AKA superdrive card, IIgs
>   floppy port, IIgs with superdrive card, IIgs with LIRON card (1 MHz only)

    If using a UniDisk 3.5 on an Apple IIgs, it should be connected 
directly to the Smartport in back. A UniDisk 3.5 connected to the 
SuperDrive card will not operate under GS/OS, and the same most likely 
applies with the Liron card (I'm not certain whether the Liron will 
work in a IIgs at all, though I may very well be wrong).

>5. grey, amber in use light -> external FDHD, compatible with //c plus
>   (800K only), IIgs floppy port (800K only) //e and IIgs with superdrive
>   card (800K and 1.44 mb)

    A small note, some external SuperDrives have "FDHD" printed on 
the front, others do not.  It is also possible to transplant an 
internal SuperDrive mechanism and place it into an old Apple 3.5 
case. I did this since it was much cheaper buying the internal 
mechanism than an external drive (only difference is the LED color 
and ID sticker underneath).

    You can easily check for this user-upgrade by looking for a two
small white posts inside (right corner) where the disk inserts. The 
FDHD mechanism only has this, one of the posts is for High Density
floppy detection (if the button is depressed, it knows your using 
an DD 400/800K floppy; the hole on HD disks allows the post to go
through).

Mitchell Spector
spec@vax2.concordia.ca