[comp.windows.ms] MFM + SCSI

akm@geriatrix.cs.uoregon.edu (Anant Kartik Mithal) (03/31/91)

Hi,

I have an MFM AT controller with two ST-251-1s running off it. I need
to add more disk space, and I don't want to get rid of my old disks.
(We've come a long way together...) So, my question is: can I add SCSI
to my machine? i.e., can I add a SCSI controller which doesn't have a
built-in floppy controller and a SCSI hard disk? My existing MFM
controller has dual floppy control.

If so, how will such a device work (i.e. how will dos and Windows know
about the SCSI disk)a? Will I have to add a device driver (which will
run off my existing drive c), which will then allow dos to access the
SCSI disk? And, will this run under windows? I seem to recall hearing
that there are problems between windows and SCSI disks.  What SCSI
disk + controller combinations are recommended? I am looking for ~80
meg at ~ 20 ms access time. I have a free 1/2 height drive slot, and
this is running on a 20 Mhz 386 motherboard.

Is there any other way of adding disk space to my machine?

Thanks for any and all help.

kartik
-- 
Anant Kartik Mithal                                     akm@cs.uoregon.edu
Research Assistant, 					(503)346-4408 (msgs)
Department of Computer Science,                         (503)346-3989 (direct)
University of Oregon, Eugene, OR 97403-1202

gyugyi@earthsea.stanford.edu (Paul Gyugyi) (04/02/91)

I have 2 MFM drives, and a SCSI, plugged into an IBM PC with an
Intel Inboard 386 accellerator card.  Works well.
Some hints:

1) Don't buy the seagate ST-02 scsi controller that costs about $50.
I doesn't come with drivers to let you use both MFM and SCSI
disks.  It simply makes the SCSI look like a MFM disk controller.

2) I have the future domain SCSI disk controller for the XT.  It
is an 8 bit card, which I needed.  Future Domain drivers will let you
use SCSI and MFM disks.  Get the full kit, as it has the driver you
need.  Now, future domain chose to install the scsi disk as a "block
device", not an "Int 13 device", which means that smartdrv and
hyperdisk won't cache the scsi drives (they won't complain either).
Luckily PC Quik Cache will cache block devices, so get that if you
get a future domain controller.  I wouldn't bother mentioning
future domain at all, execpt I hear they have a really fast SCSI-2
controller out (I have no details or hard facts).

3) don't forget about the virtualHardDiskIRQ=false (WARNING: the previous
spelling is probably wrong and won't work at all.  consult sysini.txt files).

Your best bet is to get an Adaptec controller, since that seems to be
widely used & supported.

--
Paul Gyugyi
gyugyi@earthsea.stanford.edu