IBM 5162 - Unexact Match of Hard Drive Type Number
I have an IBM 5162 (IBM XT Model 286).
For my IBM 5162, I purchased an 'MFM' hard drive, a model CRAP-E, made by Brick Hard Drives Inc.
The CRAP-E drive has a CHS (cylinder-head-sector) geometry of: 990 cylinders, 7 heads, and 17 sectors per track (SPT).
PROBLEM
I look at the table shown at the bottom of here, a table that shows me the drive type numbers and corresponding CHS geometries that can be chosen from in the SETUP ('CMOS' SETUP) of my IBM 5162, and I see that there is no match, even if I disregard WPC.
A WORKAROUND
In the SETUP, select a geometry where:
• Count of cylinders is the same or less than that of the drive; and
• Count of heads is the same or less than that of the drive.
For my CRAP-E drive (i.e. geometry of 990/7/17), the best selection using the workaround is IBM type 18, which corresponds to a geometry of 977/7/17.
As a result, my IBM 5162 is going to believe that a drive of 977/7/17 geometry is attached.
Cylinders 978 to 990 of my CRAP-E drive are not going to get used, resulting in a loss of about 1.3% capacity.