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Note 25.0                  FPJ11,KDJ11-A compatibility                No replies
FURILO::JACKSON                                      85 lines  19-AUG-1985 11:35
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      +---------------+                                    +-----------------+
      | d i g i t a l |                                    |  uNOTE # 025    |
      +---------------+                                    +-----------------+

                                                                         
      +----------------------------------------------------+-----------------+
      | Title:       FPJ11-AA Compatibility with the       | Date: 28-APR-85 |
      |                    LSI-11/73 (KDJ11-A)             |                 |
      +----------------------------------------------------+-----------------+
      | Originator: Mike Collins                           | Page 1 of 2     |
      +----------------------------------------------------+-----------------+


      Early LSI-11/73 (KDJ11-A) modules are  incompatible  with  the  FPJ11-AA
      floating  point  accelerator.   This MicroNote describes how to identify
      those modules which are compatible and those which  are  not  compatible
      with the FPJ11-AA.

      The following information refers to two identifying numbers.   They  are
      the module variation and the module revision.

      The module variation number is stamped  onto  the  end  of  the  plastic
      handles.  It will be 'M8192', 'M8192-YB' or 'M8192-YC'.

      The module revision number can be  found  on  side  two  of  the  module
      (noncomponent  side)  stamped  into  the plastic handle, or written with
      indelible ink.  This number is updated  as  the  board  is  ECO'd.   The
      designation  is a number followed by the module revision.  e.g.  441 C1,
      indicates module revision C1.

      The first LSI-11/73 module is called a KDJ11-AA and is incompatible with
      the  FPJ11-AA.   The module variation for the KDJ11-AA is M8192, and the
      module revision number is C1.   The  KDJ11-AA  can  be  upgraded  to  be
      FPJ11-AA  compatible.  Contact the local DEC office for more information
      concerning the upgrade procedure.

      Two new options have been created.  The KDJ11-AB is a  module  which  is
      fully  compatible  with  the  FPJ11-AA.   The  module  variation for the
      KDJ11-AB is M8192-YB, and the module revision number is A1 or A2.

      The third option is called a KDJ11-AC and is used for  fully  compatible
      modules  which  have  FPJ11-AAs installed onto the board by Digital.  It
      has a module variation of M8192-YC and the module revision number is  A1
      or  A2.  Therefore a KDJ11-AB becomes a KDJ11-AC by simply installing an
      FPJ11-AA.

                                                                Page 2


      The following table summarizes the above information and should be  used
      as a 'quick check' for FPJ11-AA compatibility.

      +----------+------------+------------+--------------------------+
      | OPTION   |    MODULE  |   MODULE   |     FPJ11 COMPATIBLE?    |
      |          |  VARIATION |  REVISION  |                          |
      +----------+------------+------------+--------------------------+
      | KDJ11-AA |    M8192   |     C1     |   NO (But Upgradeable)   |
      +----------+------------+------------+--------------------------+
      | KDJ11-AB |  M8192-YB  |  A1 or A2  |          YES             |
      +----------+------------+------------+--------------------------+
      | KDJ11-AC |  M8192-YC  |  A1 or A2  | YES (FPJ11-AA Installed) |
      +----------+------------+------------+--------------------------+


                                      CAUTION

              An FPJ11-AA installed on a KDJ11-AA may APPEAR  to  work
              but cache errors and parity errors may occur.

              An MXV11-BF must be  REV  C  to  be  compatible  with  a
              KDJ11-A  with  an FPJ11-AA (KDJ11-AC).  Earlier versions
              of  the  MXV11-BF  are  incompatible   with   KDJ11-ACs.
              KDJ11-As  without  FPJ11-AAs  are  compatible  with  all
              versions of the MXV11-BF.

              The MCV11-D is incompatible  with  KDJ11-ACs.   KDJ11-As
              without  FPJ11-AAs  are  compatible with all versions of
              the MCV11-D.


