INT 21,44,E / IOCTL,E - Get Logical Drive

AH = 44h

AL = 0E

BL = physical drive number (0=default, 1=A:, 2=B:, 3=C:, ...)

on return

AX = error code if CF set (see ~DOS ERROR CODES~)

AL = logical drive number assigned to physical drive

= 0 if drive accessed by only one drive specifier

= 1 if drive A:, 2 if drive B:, etc

- used to determine the last drive designator used to access

a drive if more than one logical drive designation applies

to a device

- implemented from DOS 3.2