yon@apollo.COM (David Yon) (06/29/89)
Hi all, What do people out on the net know about SCSI drives for the AT? I'm looking into either the ST138 or ST157 with the ST02 Seagate SCSI/FDC interface. What I'm curious to know is, how does the AT BIOS know how to inter- face to the drive if you have a SCSI port in the way? Does the BIOS have built-in code to recognize that a SCSI port is in the system (which I doubt) or does the SCSI port look remarkably like a drive controller board (which I would also doubt). Is it really as easy as telling the AT the drive parameters and it all just magically works? Also, I would like to continue using Disk Technician+ with the new drive, does anyone have any experience at using Disk Technician with a SCSI drive? Thanks... David Yon
dold@mitisft.Convergent.COM (Clarence Dold) (06/29/89)
in article <441b1d44.1042a@apollo.COM>, yon@apollo.COM (David Yon) says: > What I'm curious to know is, how does the AT BIOS know how to inter- > face to the drive if you have a SCSI port in the way? Does the BIOS have > built-in code to recognize that a SCSI port is in the system (which I doubt) > or does the SCSI port look remarkably like a drive controller board (which I > would also doubt). There are two answers, in the case of the Unisys 6000/50. Our BIOS does have special code, to use our controller, as if it were ST506. MSDOS, and any program using BIOS or DOS access to the disk is unaware that a SCSI controller is there. XENIX, which goes directly to the controller, not using BIOS calls, won't recognize the SCSI controller without a special driver. -- --- Clarence A Dold - dold@tsmiti.Convergent.COM (408) 434-5293 ...pyramid!ctnews!tsmiti!dold P.O.Box 6685, San Jose, CA 95150-6685 MS#10-007
rmk@frog.UUCP (Rick Kelly) (06/30/89)
In article <441b1d44.1042a@apollo.COM> yon@apollo.COM (David Yon) writes: > What I'm curious to know is, how does the AT BIOS know how to inter- >face to the drive if you have a SCSI port in the way? Does the BIOS have >built-in code to recognize that a SCSI port is in the system (which I doubt) >or does the SCSI port look remarkably like a drive controller board (which I >would also doubt). Is it really as easy as telling the AT the drive parameters >and it all just magically works? Also, I would like to continue using Disk >Technician+ with the new drive, does anyone have any experience at using >Disk Technician with a SCSI drive? > > Thanks... > >David Yon The SCSI disk controller has an extended BIOS rom that get loaded at boot time. The system will basically timeout looking for a normal floppy or winchester, and then use the extended BIOS code to poll the SCSI bus. If it finds a bootable device, you're up and away. I have been told that Seagate's SCSI boards are excellent. Rick Kelly Test Engineering Charles River Data Systems 983 Concord St. Framingham, Ma. 01701 Phone: 508-626-1011 days 508-879-2179 nights