Interrupt 21h Function 440Dh Minor Code 6Fh

Retrieves information about the specified drive.

mov ax, 440Dh            ; generic IOCTL
mov bx, DriveNum         ; see below
mov ch, 8                ; device category
mov cl, 6Fh              ; Get Drive Map Info
mov dx, seg DriveMapInfo ; see below
mov ds, dx
mov dx, offset DriveMapInfo
int 21h

jc  error

Parameters

DriveNum
Drive to obtain information about. This parameter can be 0 for the default drive, 1 for A, 2 for B, and so on.
DriveMapInfo
Address of the DRIVE_MAP_INFO structure that receives information about the specified drive.