Function 3305h Get Startup Drive

mov ax, 3305h ;Get Startup Drive

int 21h

mov StartupDrive, dl ;drive (1 = A, 2 = B, etc.)

Get Startup Drive (Function 3305h) returns a number representing the drive that was used to load MS-DOS.

Parameters

This function has no parameters.

Return Value

The DL register contains the number of the startup drive (1 = A, 2 = B, 3 = C, and so on).