Conference azur::mcc

1848.0. "DAP restrictions in the v1.2 ft kit" by DFLAT::PLOUFFE (Jerry) Fri Nov 22 1991 16:37

  The following information will be included in the v1.2 ft Toolkit
  release notes, but I thought that it was important to mention it here:

  There are two code limitations in the current implementation of the DECmcc
  dictionary.

    1.) Identification codes for all dictionary objects (classes (global
        and child), attribute groups, attribute partitions, attributes,
        event groups, event partitions, events, directives, requests,
        responses, exceptions, request arguments, response arguments and
        exception arguments) must be less than 65536 (2 raised to the 16th
        power).

        This is due to a tradeoff made in the implementation of the dictionary
        file key structure to keep the size of the dictionary file keys (and
        thus the size of the dictionary file) relatively small.

        Identification codes greater than or equal to 65536 will be accepted
        by the MSL Translator and DAP, but the high order bits (greater than
        bit 15) will be stripped off resulting in an unexpected code.

    2.) The numerical values assigned to enumerations must be less than
        1048576 (2 raised to the 20th power).

        These numerical values are used as ILV tags when they are encoded
        into the dictionary record.  ILV tags, as documented in the v1.1
        DECmcc System Reference Manual, must be less than this value.

        Numerical values greater than or equal to 1048576 will be accepted
        by the MSL Translator but not by DAP.  DAP will produce the error
        message "Invalid IDcode" when it tries to store this data and the
        processing of the rest of the DAP command file will be aborted.

  Both of these limitations are implementation restrictions not architectural
  restrictions.  Both will be addressed after v1.2 field test.  Impact
  investigations are in progress.

                                                                    - Jerry