INT 13 - HARD DISK - DRIVE DIAGNOSTIC (XTIBM PC XT,PSIBM PS/2, any model) AH = 13h DL = drive number (80h = first, 81h = second hard disk) Return: CF set on error CF clear if successful AH = status code (see #00234 at AH=01h) AL = 00h SeeAlso: AH=12h"HARD DISK",AH=14h"HARD DISK"