Re: Disk drive / controller questions

[pubpc1@library.ucla.edu]

david@wraith.cs.uow.edu.au (David E A Wilson) wrote:
>James Noyes <jnoyes@quality.net> writes:
>>   Here's the story - I'm looking for a specific controller.  I need
>>a controller that will go in an Apple //e and will run both a PAIR of
>>UniDisk 3.5's and a PAIR of Disk II's.  It needs to occupy a SINGLE
>>slot (preferably slot 6) and phantom-slot the UniDisks to slot 5 (or
>>any other slot, actually) under ProDOS 8, while still allowing the
>>actual device in slot 5 to function (it's my mouse) - similar to what
>>happens when a second 3.5 drive is mapped to slot 2, drive 1 under
>>ProDOS 8 on a IIgs, while still allowing the serial port to work.  I
>>don't care if it doesn't allow the UniDisk 3.5's to work under DOS
>>3.3, since I wouldn't use them for that anyway.
>
>I have a UDC with one Apple 3.5 on the first connector and one 5.25"
>drive on the 2nd connector (with a home made 19 pin to 20 pin adaptor).
>I have also run it with 2x Apple 3.5 and 1x 5.25". It should do 2x 5.25"
>[I could try it out by plugging in my DuoDisk from my other //e] as well.
>
>[looks back and sees the reference to UniDisk 3.5] Oh dear...
>
>Unfortunately my UDC card seems to be unable to drive a UniDisk 3.5.
>I tried one and it did not work so I have Apple 3.5 drives instead.


The UDC that I used WAS able to handle the UniDisk 3.5.  The UDC ROM was
upgraded after the Laser 128EX/2, which used it, came out.  The new
firmware was able to drive a UniDisk 3.5 just fine, although the speed
is dog slow.  I don't have the card with me right now, but you can check
to see if a particular card will work with a UniDisk by the version number.
Older UDC cards are identical and all that is needed to upgrade them would
be to burn new ROMs for them.

Otherwise, there is a way to modify the UniDisk so that it behaves like
an AppleDisk 3.5.  It involves flipping the controller board, but I forgot
the details.

-Scott G.