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
- -

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