Having problems with SCSI MO drives

[Guy Sotomayor]

On Wed, 2004-09-08 at 08:40, Vintage Computer Festival wrote:

> 
> The problem is I'm trying to get a system working with several different
> old MO drives (Maxoptix Tahiti 1, Pinnacle Micro REO-650/1300, Sony
> <forgot the model>).  The Maxoptix is not even being recongized, and may
> well be dead dead dead.  The Pinnacle is being recognized but I'm getting
> the errors mentioned.  The Sony drive gets recognized OK and the system
> boots but then I get a bizarre message in the Adaptec BIOS that says it's
> not a disk drive(!)  Well then what is it?  It's a Macinstor drive (ugh,
> can't think...forgot who the manufacturer is).

ARG!  I played with all of these (and continually cursed the day I first
had to deal with them) while I was developing SCSI stuff at IBM.

When I delt with the Tahiti-1 it had continuous microcode updates and
the optical cartidges were not compatible with anyone else's.

The major problems with these drives is that they reported honestly what
they were (r/w optical drives).  However, all of the PC code (BIOS, DOS,
etc) thought optical drives were CD-ROMs and were utterly confused by
anything that wasn't (especially 512 byte sector optical drives...and
ones that didn't have the RO bit set).

More reasonable OS's (aka UN*X) handled these beasts a bit better but
the drives themselves were *always* a headache.

As someone previously mentioned, ISA DMA is fiddly at best.  Go do this
on a PCI machine.

You probably also want to make sure that the SCSI HBA is configured for
single ended and 5MB/sec or lower (ie async).  These SCSI interfaces on
these drives are old and they will probably get very confused with the
more modern auto-config stuff.

-- 

TTFN - Guy