Memory Control Block

                             Memory Block Layout                              

        00h     BYTE    ID ("Z"=Last MCB, "M"=Another MCB Follows)
                        Probably from Mark Zbikowski
        01h     WORD    Segment Address of corresponding PSP
                        Zero if unallocated
        03h     WORD    Number of paragraphs in block
        05h   3 BYTEs   Unused
        08h   8 BYTEs   File Name (no extension) of owning program.
                        Only used in DOS4, and only for programs run
                        through the EXEC function, otherwise unused.