Subject: Re: Disks for uVax II
To: Douglas S. Meade <>
From: Michael Kukat <>
List: port-vax
Date: 06/22/1999 17:39:59
Hi !

Emanuel answered the most, the rest is:

> I've got another Micropolis 1375 (170Mb) that has a SCSI
> interface, but looks identical in every other respect to the
> RD53 drives, which say they are Micropolis 1325.  Could it
> be converted easily to a drive the uVax would be happy with,
> say by attaching a mounting from an old RD53?

Take a very close look at the controller PCBs. If all connectors are at
exactly the same place, there could be a bit of a chance, sometimes the
controllers are the same for multiple drives. If the drive geometry is
stored on the disk itself, this COULD work. But i think this is a bit
unusual on old ST506-disks. Try to get more information about the SCSI
drive, especially, how it is formatted. SCSI drives often use RLL encoding
and sometimes do a CHS mapping in a way to get more data onto the media by
putting more sectors on the outer tracks than on the inner tracks. If such
things apply to your SCSI drive, just forget the experiment, but if you
see an MFM version of this drive with the same physical data (cylinders,
heads, sectors), you could try it. But be careful: I'm not responsible, if
you trash the SCSI drive by this. If connectors are the same, the chance
to trash the controller is not that big.
I did such things, i think it were Seagate drives or so, too long ago, but
this doesn't mean, it works with other drives also.

If you do, spin up the drive alone, and listen to the head and watch the
LED. If it spins up, it should mode the head several times, and then the
LED must be off and the drive must keep spinning. If so, just try it, but
don't wonder, if it's still a RD53 :-)

so long.. Michael