"Imaging" a MFM drive?

[Philip Pemberton]

Joachim Thiemann wrote:
> That may be a difficult bit.  All documentation - if there ever was
> some - is long gone.  The Amiga and Sidecar have been through many
> moves, and was last used sometime around 1993/4 when it was replaced
> by the A3000.

Ouch...

In any case I'd try the "standard" parameters first. I do wonder if the 
controller has its own onboard store for the disc parameters, which 
would mean you didn't have to bother trying to figure them out.

Actually, If the partition table is DOS/PC standard, the C:H:S of the 
drive should be stored in CHS 0:0:0... (I spent far too much of my life 
doing low-level programming on DOS boxen :P )

> I found a page describing the jumpers for the controller by googling
> "Xebec" and the assembly-number (104866 or something, I don't have it
> in front of me) so moving the address is certainly an option.

Actually, I just found this:
<http://artofhacking.com/th99/c/U-Z/21077.htm>

Which implies that the drive type is set by jumpers on the Xebec board. 
So you probably won't have to figure out the C:H:S mappings manually, 
assuming the jumpers are set properly.

> I was asking since a google returned a message on the kernel
> developers list (199? timeframe, 2.0 kernel) complaining about the
> nonfunctional xd driver and suggesting it'd be removed in future.

Well, either someone's fixed it, or it's been left in the source tree 
and removed from the kernel config system (make menuconfig).

> I still have a set of original RH5.2 install CD's I'll check those
> once I find them :-)

That should work pretty nicely... assuming the chipset on the PC doesn't 
do/need anything weird.

> Hmmm, maybe an old Minix system could talk to the card :-) od the raw
> device to the serial port, then capture the octal data and reassemble
> the image file...

That's one way to do it, I suppose. I'd sooner use Xmodem (which CRCs in 
and outbound data) but I guess that's just me... :)

-- 
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/