Re: Diff. types of Unidisk controller?

[shack@onyx.southwind.net (Randy Shackelford)]

Ben Lai (benlai@unixg.ubc.ca) wrote:

: I saw a recent ad from Shreve Systems where they are selling a 5.25" 
: Unidisk Controller card and a 3.5" Unidisk Controller card. 

: I was under the impression that all Unidisk controllers are the same 
: (hence "Uni" - disk). Does anyone know what are the differences between a 
: 5.25 and a 3.5 inch Unidisk controller?  Would I be able to connect a 3.5 
: Unidisk drive to a Unidisk controller that I got with my 5.25 duodisk?

There was a drive known as the Unidisk 5.25 at one time. It's the beige
version of the Apple 5.25 drive. The card that runs daisychainable 5.25 drives
was called the Unidisk 5.25 card once upon a time. This card will run any
DB19 connector equipped 5.25: Disk //c, Duodisk, Unidisk 5.25, and Apple 5.25.
It won't run a 3.5 drive. I have a few 5.25 cards on hand, and early ones say
"I/O controller 655-0101-" with a revision letter. Later ones say "Apple 5.25
controller card 655-0101-" some revision letter. I'm not positive but the "I/O
controller" card may be made for a Duodisk. Unidisk 3.5 cards say "Apple 3.5
floppy disk drive interface card" and mine from mid '86 bears the numbers
603-9107-A and 820-0117-A. This card will run intelligent devices; I've used
Unidisk 3.5s and a CT-20c hard disk with it.
--
Randy Shackelford
shack@southwind.net