INT 67h,  4Eh  GET OR SET PAGE MAP                                   . 3.2

On entry:
        AH = 4Eh
        AL = 00h if getting mapping registers
             01h if setting mapping registers
             02h if getting and setting mapping registers at once
             03h if getting size of page-mapping array
        DS:SI = pointer to array holding information (AL=01/02)
        ES:DI = pointer to array to receive information (AL=00/02)

Return:
        AH = status
            00h successful
                AL = bytes in page-mapping array (subfunction 03h only)
                array pointed to by ES:DI receives mapping info (AL=00/02)
            80h internal error
            81h hardware malfunction
            84h undefined function requested
            8Fh undefined subfunction parameter
            A3h contents of source array corrupted (EMS 4.0?)

Note: this function was designed to be used by multitasking operating
      systems and should not ordinarily be used by appplication software.