RadiSys EXM-9 Reference page 14

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2. For use by the translation mapping, select either 63 or 17 sectors per
logical track. Call this value S. Use S of 63 for drives greater than 136
MB, and S of 17 for smaller drives.
3. Compute the minimum number of logical heads needed to cover the
capacity of the drive. Call this value H. H is computed as
H = ___B___
1024 × S
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Round H up to the next higher integer.
4. Find a drive type entry in the BIOS fixed-disk menu whose logical
number of sectors per track (S) matches the number you've selected (17
or 63) and whose number of heads is the smallest number at least as large
as H.
5. Some programs (e.g., FDISK in earlier versions of DOS) need to under-
stand the number of cylinders. If you need this value, the number of
logical cylinders on the drive is given by the integer no larger than
__B__
H × S
Use this value for software that needs to understand the number of cylin-
ders on the drive (e.g., the FDISK disk partitioning program).
As an example, consider the Conner Peripherals CP3204F 200 MB drive. The
number of blocks on the drive is specified as 415,264. Because of the size of the
drive we use 63 sectors per logical track (S). The number of logical heads is
415264/(1024×63), which rounds up to 7. Drive type 36 in the EPC BIOS's fixed-
disk menu is the proper choice.
For two other commonly used IDE drives, the Conner Peripherals CP3044 and
CP30104, the appropriate drive types are 24 and 33 respectively.
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EXM-9 Hardware Reference