BV> If you are going to use LBA mode, then you should start with a
BV> freshly formatted disk or a disk which does NOT contain any data.

Well, thats certainly safest, but its not necessarily the only way.

BV> LBA works below the OS at the BIOS level.

Not with OS2 it doesnt.

BV> Your OS makes calls to the disk which the BIOS handles.

Nope, OS2 doesnt use the bios for the hard drive access. Which is why
the 1024 cylinder limit only applys to getting the boot manager booted,
and it can then boot a partition outside that, or even on another drive.

BV> If you format the disk for X heads, Y cylinders, Z sectors
BV> using Normal access then configure it for A heads, B cylinders,
BV> C sectors using the LBA mode, things are going to get pretty
BV> screwy because the BIOS sees it as a different disk.

Depends. If you install a large drive with >1024 cylinders
with an OS which doesnt give a damn about that like OS2, you
dont necessarily get a different mapping from the CHS to the
linear sequence of sectors seen with LBA when you enable it.
Only if the mapping changes will you necessarily have a problem.

BV> It doesn't simply convert all standard requests into LBA requests.

It does actually with DOS on some configs. The higher level software
still makes its requests in terms of the CHS values and the bios does
the translation between those and the LBA request down the cable.

BV> Well, it probably does but the sectors
BV> aren't going to be in exactly the same place.

Depends entirely on the mapping between CHS
and the logical block, the sector number.

BV> The ACCESS method is different.

Yes, but that doesnt necessarily mean that the sector sequence is.
There is no reason why it cant result in the same sequence of sectors.
@EOT:

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