1 SIDPARSE
    The SID (System IDentification) register is comprised of several fields.
    The  format  of  the  SID  varies  from  one  class of VAX processors to
    another.  Not all processor classes have serial number fields.   In  ALL
    cases, the left most byte of information is the CPU class number.

    The  SIDPARSE command procedure takes apart a SID value and displays the
    relevent  fields.  A SID can  be supplied or, if  <cr>  is entered,  the
    current system's SID is obtained and used.
2 CPU_Classes
    The CPU class numbers and the SID formats are:

                      Processor    Number
                      ---------    ------
                      uVAX-I          7
                      uVAX-II         8
                      VAX-730         3
                      VAX-750         2
                      VAX-780,        1
                      VAX-782,        1 
                      VAX-785         1
                      VAX-8600        4
2 Small_CPU_Format
           31 23 23 16 15  8 7   0
          +-----+-----+-----+-----+
          |     |     |           |    The uVAX I and uVAX II SID format.
          +-----+-----+-----+-----+
             ^     ^        ^
             |     |        +------ Not Used
             |     +--------------- Micro Code Revision
             +--------------------- Cpu Type (7 for uVAX-I, 8 for uVAX-II)
2 Medium_CPU_Format
           31 23 23 16 15  8 7   0
          +-----+-----+-----+-----+
          |     |     |     |     |    The VAX-730 and VAX-750 SID format.
          +-----+-----+-----+-----+
             ^     ^     ^     ^
             |     |     |     +--- Hardware Revision Level
             |     |     +--------- Micro Code Revision Level
             |     +--------------- Not Used
             +--------------------- Cpu Type (3 for VAX-730, 2 for VAX-750)

                              NOTE: The VAX-725 is a VAX-730 processor.
                                    The VAX-751 (OEM) is a VAX-750
                                    processor.
2 Large_CPU_Format
           31 23 23 15 14 12 11  0
          +-----+-----+-----+-----+
          |     |     |     |     |   The VAX-780 and VAX-8600 SID formats.
          +-----+-----+-----+-----+
             ^     ^     ^     ^
             |     |     |     +--- Serial Number
             |     |     +--------- Plant (where CPU was manufactured)
             |     +--------------- Hardware ECO Level
             +--------------------- Cpu Type (1 for VAX-780, 4 for VAX-8600)

                              NOTE: The VAX-782 is a VAX-780 processor.
                                    The VAX-785 is a VAX-780 processor,
                                    although the high bit of the ECO is
                                    always ON for 785's.
