32Meg Limit and > 512 Byte Sectors

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2 total messages Started by Brian Who? Tue, 31 Jul 1990 20:47

#1742

Author: Brian Who?
Date: Tue, 31 Jul 1990 20:47

14 lines
1252 bytes

     I am writing a SCSI device driver for the Seagate ST-01 interface card
and want to have it utilize large drives without having to partition them.
In reading thru the documentation available on Bios Parameter Blocks, I tried
to get around the 32Meg drive limit by makeing the sectors larger (2048).
What I ran into was that DOS refused to use the driver and complained about
"Invalid Sector Size in C:\SCSI.SYS".  It turns our that you cannot have
a loadable driver that defines a sector size larger than the largest sector
size used by the internal/resident drivers.

     Now for the question.  Does anyone know of a way to convince DOS to
allow the larger sector sizes?  It might be possible to create a boot floppy
with large sectors, but I don't want to have to boot from a floppy all the
time.  Help!?!?!?!?

Re: 32Meg Limit and > 512 Byte Sectors

#1855

Author: Pasquale Leone
Date: Wed, 01 Aug 1990 19:00

8 lines
912 bytes

    Apparently there is a byte(s) location in one of the hidden dos files
that determine the sector size used. My PRIAM disk manager patches this
code byte if I want to allow disk sizes larger than 32Meg. The problem
with this method is that disk access slows down (so the manual claims).
I don't use this mode so I don't know how well it works.

pasquale@sgl.ists.ca

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