其中一段程序的job:
; This next section of code tries to find an ACTIVE (i.e., bootable) entry in
; the Partition Table. The first byte of an entry indicates if it's bootable
; (normally an 80h, but in this case, anything from 81h through FFh as well!)
; or not (a 00h); any other values (from 01h through 7Fh) in these locations
; means the Table is invalid! If none of the four entries in the Table is
; active, then the INT 18h instruction will be executed; for which most BIOS
; today (see note at 062B below) will display "PRESS A KEY TO REBOOT".