Re: 3.5 for 2c

[david@wraith.cs.uow.edu.au (David E A Wilson)]

dempson@swell.actrix.gen.nz (David Empson) writes:

A very good summary of Apple's 3.5" drives and controllers. It should be
added to the FAQ.

>Universal Disk Controller (from Central Point, also known as the Lazer
>Disk Controller)
>This works on a IIe.  I don't know if it works on a IIgs (but there
>wouldn't be much point anyway).

Looking at the code it should work on a //gs. If it finds a 65816 then
it plays with the //gs CPU speed register. Not the way I would have
checked for a //gs! It relies on the following code not causing
problems on a 6502/65c02:

c61c    clv
c61d    sep     #0xea
c61f    nop
c620    bvs     0xc629

>It supports 5.25" drives and the Apple 3.5 Drive. Connecting a
>SuperDrive to this card will make it act as an Apple 3.5 Drive.
>I don't know if this card supports the UniDisk 3.5.

I have one of these cards and it does not support the UniDisk 3.5
but does (marginally) support the Macintosh external 800k drive at
a 6 fold slow down. 9 minutes to scan an entire disk! I understand
that earlier models of this card (possibly the ones with both 19 &
20 pin connectors?) supported UniDisk 3.5 drives as well.
-- 
David Wilson				+61 42 213802 voice, +61 42 213262 fax
Dept Comp Sci, Uni of Wollongong	david@cs.uow.edu.au