btdrv parameter can't identify the right drive

[val43]

I've got linux installed on the internal drive of a laptop, and xp on an external usb drive.

The internal drive has 4 partitions. grub is in the first.
The external drive has 2 partitions. ntldr is in the first.

I'm launching plop from grub, so I need to edit plpbt.bin properly.

I tried these settings with plpcfgbt:
vm=800x600 fnt=bios prf=1 prfname=Arch btdrv=80h btprt=1

then:
prf=2 prfname=XPusb btdrv=81h btprt=1

and at last:
dprf=2

But looking at the profiles in Plop setup (while it's running), it appears that both are linked to HDA partition 1, which should be the linux /boot partition on the internal drive.

Trying to boot both linux and xp reports: "No valid bootsector signature". If i try to boot anyway, nothing happens.
booting USB fails (freezes as soon as the windows logo appears).
If I change the settings while grub is running and link HDB (partition 1) to the 2nd profile, it's the same (no valid boot sector signature)..

booting directly from the usb drive works, but i'd like to use Plop for this job!
is it possible to have it get the device numberings right? It looks like that's the problem

[Elmar]

post the modified plpbt.bin (press additional options, attachment)

[val43]

here 


EDIT:
to be precise, both grub and ntldr are installed on the MBR of each drive, not the first partition.



OT:
also, the suggested grub2 configuration didn't work for me. this does:

Code Select Expand


menuentry "Plop Boot Manager" {
    set root=(hd0,msdos1)
    linux16 /plpbt.bin
}

the path is relative to the /boot folder. the absolute path for me is /boot/plpbt.bin