In a few situations, none of the drive types specified in your BIOS
setup program will match your drive, and the setup program will
not provide an opportunity to specify a custom drive type. In this
case, consider the third option described on page 6 — allowing
your ST9100A or ST9100AG drive to mimic one of the BIOS-sup-
ported drive types. During the BIOS setup process, simply select
a drive type with a capacity that is

less than or equal to

the drive’s
BIOS calculated capacity listed in the table on page 6. This drive
type should have no more than 1,024 cylinders, 16 read/write
heads, or 63 sectors per track. In addition, the total number of
sectors for that drive type (listed in the setup program) should not
exceed the number of cylinders times the number of read/write
heads times the number of sectors per track. In other words:

Total sectors per drive

≤

(No. cylinders)

×

(No. read/write heads)

×

(No. sectors/track)

BIOS compatibility recommendations
The ST9100A and ST9100AG are AT interface compatible drives,
which conform to ATA specifications. The host system BIOS must
provide support for the AT interface command set. Consult the
system documentation for information on the AT interface within
your system. Several key compatibility issues are discussed
below.
In accordance with ATA specifications, the BIOS must reset any
emulation/translation parameters after a hard reset is received
from the host.
In some configurations, the ST9100A and ST9100AG drives
supply 16 bytes of Error Correction Code (ECC) with the Read
Long and Write Long commands. Depending on the drive type,
your system BIOS may look for 4 bytes of ECC. If your system
BIOS expects 4 bytes of ECC and the drive supplies 16 bytes,
ST9100A and ST9100AG Installation Guide, Rev. A 7