INT 1aH b001H: Query ROM/Hardware-Based MRCI Support

 Expects: AX    b001H
          CX    4d52H ('MR')
          DX    4349H ('CI')
          ──────────────────────────────────────────────────────────────────
 Returns: CX    4943h ('IC', if successful)
          DX    524dh ('RM', if successful)
          ES:DI address of an MRCInfoRec describing the MRCI server
          ──────────────────────────────────────────────────────────────────
    Info: See INT 2fH 4a12H for information on the parameters.

          This fn is defined by the MRCI API as a way for a hardware or
          ROM-based MRCI server to make its presence known and as a way for
          a software-based MRCI server to learn whether it should install
          itself.

          The idea is that a ROM-based and/or hardware-assisted compression
          system will be installed during ROM-Scan, before DOS or other
          operating system is loaded and thus may be unable to take control
          of the standard INT 2fH vector.

          The MRCI spec recommends that applications check for the server
          via INT 2fH 4a12H and if it is not found there, use this INT 1aH
          service.

   Notes: Before using INT 1aH, you should check its interrupt vectors to
          make sure that it is not 0000:0000.

See Also: MRCI API
          DoubleSpace Overview
          DoubleSpace API
          INT 2fH: Multiplex Interrupt
          DOS Functions
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