Re: WD1002A-HDO

On Mon, Nov 22, 2021 at 12:54 PM <ruud_at_baltissen.org> wrote:
>
> Hallo allemaal,
>
>
> I found this WD card that, according some info I found, is a SASI to
> MFM convertor. My idea: can it replace the converter in the CBM 9060
> or 9090?
>
> I contacted a friend of mine, Fred Jan Kraan, but he hasn't answered
> my mail yet. It seems he is more than familiar with this card.
>
> My questions:
> - Anyone familiar with this card?
> - if so, could it replace the original converter?

I am not familiar with the WD1002A-HDO but I can provide some info on
the original card as one point of the comparison.

The CBM D9060/D9090 shipped with an OMTI 2501 card.  I have never been
able to find docs for this card in 25 years of looking.  What I did
find just now is a mention of that class of card in some newer docs:

  http://www.bitsavers.org/pdf/sms/OMTI_5x00.pdf

Apparently the 5000-series is somewhat compatible with the older
2000-series.  They do not claim command compatibility specifically,
but they do mention format/track compatibility, which is a huge deal.

I am not aware of anyone (myself included) ever going through the
D9060/D9090 firmware to pull out all the SASI commands used.  The ones
to read and write disks are almost certain to be standard ones.  The
two vendor-specific things are going to be in whatever initialization
packet is sent (like ASSIGN DISK PARAMETERS - $C2) and possibly
low-level formatting/reading (FORMAT DRIVE/CHECK TRACK FORMAT -
$04/$05).

Certainly the OMTI 5000-series is an excellent place to start to
understand the 2501, especially hand-in-hand with seeing what the
drive firmware is doing.

Cheers,

-ethan