Timothy Daniels wrote
Antoine Leca wrote

rdisk(N) is the "real" disk number (as assigned by the BIOS - 0x80; and
up to 3 according to MS doc).

You can also think of "rdisk()" as meaning the
"relative disk position", that is, relative to the head of the BIOS's
hard drive boot order.

No you cant.

Since the boot order can be adjusted manually by the user via keyboard
input to the BIOS, the hard drive referred to by "rdisk(0)" can be
changed at will.

No it cant. The boot order setting doesnt
change the N in the rdisk entry.

Thus, "rdisk(0)" will refer to the top of the boot
order list, "rdisk(1)" will refer to the next in the list, "rdisk(2)"
will refer to the next after that, etc.,

No it doesnt. It has nothing to do with the boot order list at all.

It JUST refers to the physical order.

but which hard drive those arguments refer to only
depends on cabling and I/O channel in the default case.

In all cases, actually. The boot order in the bios is irrelevant to that.