INT 0x13 function AH=0x48 doesn't work

[Holus]

Pffff

I try to read the diskparameters from USB device with INT 0x13 function AH=0x48

This fails by setting CF and AND AH=0x01!
This function is not supported.

But if I check function AH=0x41 of INT 0x13
CF=0
BX=0xAA55 (like the return value should be)
CX=0x0005 = 101b => functions (AH=42h-44h,47h,48h) supported
DH=0x08
AX=0x21 => 2.1 / EDD-1.1

so far so good!!!

When I use function AH=0x48 (should be supported)
It returns
CF = SET
AH=1 (function not supported)

Hatsikideee????

I don't understand!!!

[Holus]

Pfffff x2

I solved it.

Changed
BOOTDRV times 0x42 DB 0x00
in
BOOTDRV times 0x42 DB 0xFF

for some computers flag word at DS:[SI+2] is not 0x0000

NOT DELL ONLY!!!!!

And now it works fine!!!

[Brynet-Inc]

Thanks for reading the forum rules and using colours, it means a lot to us.