"Rod Speed" wrote:
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.


I stand by my claim, Rod. You can check if you want,
and you can make all the denials you want, but it is true,
and anyone can check that out - the "rdisk()" parameter
is relative to the top of the hard drive boot order, and it
only relates to physical position, i.e. cable position or
IDE channel number, in the default case. In the DEFAULT
case, the hard drive boot order is:

Master, IDE channel 0,
Slave, IDE channel 0,
Master, IDE channel 1,
Slave, IDE channel 1.

But when this order is changed in the BIOS, the
meaning of "rdisk()" changes physically, but it retains
its logical meaning as a reference to the boot order.
That means that "rdisk(0)" will ALWAYS refer to the
head of the boot order, regardless of which physical
hard drive is put at the head of the boot order, and
"rdisk(1)" will ALWAYS refer to the next one in the list.

Accordingly, I code boot.ini files to implement
switching between up to 7 or 8 clone OSes which are
resident simultaneously on 3 hard drives in my computer,
and the "rdisk()" parameter has always meant what I've
described above. I base this on the behavior of my
Dell Dimension XPS system which is about as common
as a PC can get.

*TimDaniels*