Int 60 Fn 03  - Mdebug - Pop Up                                            [G]

   AH = 03h
   DS:SI -> password or a null byte
   ES -> new value for the register SE
   DI -> new value for the register OF

Return: AX = return code
       FFFFh call not allowed
       FFFEh password is invalid
       FFFDh display mode is invalid
      else successful

See Also: AH=04h"MDEBUG"