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 (see #2980)

See Also: AH=04h"MDEBUG"

(Table 2980)
Values for MDEBUG return code:
 FFFFh call not allowed
 FFFEh password is invalid
 FFFDh display mode is invalid
 else  successful