Re: Disk ][ cards

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

In article waynes@intergate.bc.ca writes...

>I've become curious about the Disk ][ Interface card for some
>reason. Hopefully someone can answer my oddball questions.
> 
>I have some Disk ][ interface cards. They have 2 different part
>numbers. One is 600-0037 . Am I correct in assuming this is
>the first Disk ][ interface card? The other is 650-X104.
>Did Apple use any other numbers on their Disk ][ interface
>cards? I�m not counting theI/O controller of course*

    The bottom line is all Apple II 5.25 controllers, at least
those manufactured by Apple Computer, are functionally identical.
The main difference is early cards had a dual set of IDC-20 male 
pins directly on the card, while newer ones replaced that with
a D-19 female connector that attached to the back port. Using an
adapter, you can connect newer drives to older cards (or visa-
versa of course).

    One important difference has do with the PROMs on early
Disk II controller cards, which only supports 13 sector disks
(DOS 3.3 and ProDOS-8 require the 16 sectors PROMs). In all
my years an Apple II user, I've never seen a controller with
the original PROMs. They're quite rare as far as I know.

Mitchell Spector
spec@vax2.concordia.ca