X-Hacker.org- Ralf Brown's Interrupt List (Part 1,2) - int 21 - dos 4.0

Click above to get retro games delivered to your door ever month! X-Hacker.org- Ralf Brown's Interrupt List (Part 1,2) - int 21 - dos 4.0 - get boot drive

INT 21 - DOS 4.0 - GET BOOT DRIVE
        AX = 3305h
Return: DL = boot drive (1=A:,...)

Online resources provided by: http://www.X-Hacker.org --- NG 2 HTML conversion by Dave Pearson