Some drive problems associated with older size barriers and drives that are small by
today's standards, can be avoided simply by avoiding the use of BIOS hard disk
autodetection and entering drive parameters manually. Yes, I know, I am always saying to
use autodetection. I do think it is the best
way for most people to set up their drives--assuming their BIOS is new enough and supports
the drives being used.
In some cases, for example, where the BIOS wraps around when the disk is too large, you
can get around the problem by manually entering the maximum parameters that your disk can
support. Let's suppose that you have a 540 MB hard disk that your old 486 system is
choking on. The drive has 1048 (logical) cylinders, 16 heads and 63 sectors per track. If
you manually set the disk up in your BIOS as having 1023 cylinders, 16 heads and 63
sectors per track, it will probably work fine, but as a 528 MB disk. You still get the use
of 97% of the disk.
Note that this technique will be of no help for modern systems with large drives; for
example, it will do nothing to get around larger size barriers such as the 8 GB barrier.
Next: Int 13h Extensions
