INT 2F U - Quarterdeck - QEMM/QRAM v5.0+ - GET HIRAM MEMORY CHAIN
        AX = D201h
        BX = 4849h ("HI")
        CX = 5241h ("RA")
        DX = 4D30h ("M0")
Return: BX = 4F4Bh ("OK")
        CX = segment of start of HIRAM chain
        DX = QEMM/QRAM code segment
Notes:  QEMM/QRAM/VIDRAM/MANIFEST will search for a free AH value from D2h
          through FFh, then C0h through D1h
        QEMM and QRAM both responded the same
        the HIRAM memory chain has the same format as the regular DOS 4.0
          memory chain (see INT 21/AH=52h), except that XMS Upper Memory Blocks
          have the block header program name field set to "UMB"; blocks whose
          "owner" field is set to the QEMM/QRAM code segment returned in DX
          are locked out regions such as video memory and ROMs.