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Note 23.0                    MicroVAX I->II upgrades                  No replies
FURILO::JACKSON                                     248 lines  19-AUG-1985 11:31
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      +---------------+                                    +-----------------+
      | d i g i t a l |                                    |  uNOTE # 023    |
      +---------------+                                    +-----------------+

                                                                         
      +----------------------------------------------------+-----------------+
      | Title: MicroVAX I to MicroVAX II Upgrade Issues    | Date: 28-APR-85 |
      +----------------------------------------------------+-----------------+
      | Originator: Mike Collins                           | Page 1 of 5     |
      +----------------------------------------------------+-----------------+


      This MicroNote  describes  the  hardware  issues  in  upgrading  from  a
      MicroVAX I to a MicroVAX II.

      The Add-On and  Upgrades  group  within  Digital  Equipment  Corporation
      announced  a  formal  upgrade  kit  at  the  time  of  the  MicroVAX  II
      announcement.  For more information about this program contact  a  local
      DEC  sales  representative.   This MicroNote is intended for those users
      who wish understand the issues in an upgrade.

      Reference MicroNote #22 for a detailed description  of  the  differences
      between the processors of the MicroVAX I and MicroVAX II systems.

      Upgrading a MicroVAX I to a MicroVAX II is straightforward  because  the
      two  systems  share  many  common  components.   First  of  all the BA23
      enclosure is used by both systems, this includes  the  backplane,  power
      supply,  control  panel,  and  I/O patch panel.  The 5 1/4" disk devices
      used on a MicroVAX I are also compatible with the  MicroVAX  II.   Since
      I/O  devices  for  both  machines  are  Q-bus  devices they are directly
      compatible with the new processor.  The  upgrade  process  does  however
      involve  replacing the processor, the memory, the 5 1/4" disk controller
      and the  processor  cabinet  kit.   Each  of  these  upgrade  issues  is
      addressed in detail.

      An upgrade example is shown at the end of this MicroNote.

      THE PROCESSOR UPGRADE:
      The MicroVAX I CPU is made up of two quad modules, the memory controller
      ('MCT') and the data path ('DAP').  These two modules occupy slots 1 and
      2 in the backplane.  Both of these modules are replaced  with  a  single
      quad  module,  the  MicroVAX II CPU which must be placed in slot 1.  The
      MicroVAX II CPU module includes 1 MB of memory and  the  MicroVAX  78132
      floating  point  unit.   Slot 2 previously used by the MicroVAX I is now
      available for expansion memory or other options.


      THE MEMORY UPGRADE:
      The memory system designed  for  the  MicroVAX  II  is  unique  to  that
      processor,  therefore  the Q-bus memories used in the MicroVAX I must be
      removed and replaced by the new type.

                                                                Page 2


      If the MicroVAX I being upgraded has only 1 MB of main memory  then  the
      processor  and  memory  can  both  be  replaced with the MicroVAX II CPU
      module.  Additional memory  may  be  added  to  a  MicroVAX  II  CPU  if
      necessary.   Besides  the  1  MB of on-board memory, the MicroVAX II CPU
      will support a maximum of 2 memory expansion boards.   These  additional
      boards  must  be placed immediately after the processor in slots 2 and 3
      of the backplane.  The memory modules communicate with the CPU over  the
      C-D interconnect of the backplane and an over-the-top cable.  A cable is
      shipped with each memory module.

      Figure 1 is an example of  how  the  processor  and  memory  boards  are
      configured into a system.  If the dual height memory expansion module is
      used (MS630-AA) it must be placed in the C-D side of the backplane.  The
      memory  modules  may  be  placed in any order in slots 2 and 3.  Table 2
      lists the memory expansion options.

                                      WARNING

              Both the MicroVAX II  CPU  and  MS630  memory  expansion
              modules  must  be placed in backplane slots with the C-D
              interconnect.  Damage may result if  these  modules  are
              placed  in backplanes with Q-bus signals on both the A/B
              and C/D sides.


      Table 2 - MS630 Memory Expansion Modules

      +----------+---------------+---------------+
      |  MEMORY  |  MEMORY SIZE  |  FORM FACTOR  |
      +----------+---------------+---------------+
      | MS630-AA |    1 Mbyte    |      Dual     |
      +----------+---------------+---------------+
      | MS630-BA |    2 Mbytes   |      Quad     |
      +----------+---------------+---------------+
      | MS630-BB |    4 Mbytes   |      Quad     |
      +----------+---------------+---------------+

        Figure 1 - Processor and Memory Configuration
           +-------------------------------------+
           | +---------------------------------+ |
         1 | |  MicroVAX II CPU   ==========   | | 
           | +---------------------|      |----+ |
           +-----------------------|      |------+
           | +---------------------|      |----+ |
         2 | |  MS630-B           ==========   | | 
           | +---------------------|      |----+ |
           +-----------------------|      |<--------Memory Expansion 
           |                 +-----|      |----+ |       Cable
         3 |    MS630-AA---->|    ==========   | | 
           |                 +-----------------+ |
           +-------------------------------------+
         4 |                                     |
         . |    Additional slots                 |
         . |                                     |
         8 |                                     |
           +-------------------------------------+

                                                                Page 3


      THE RQDX DISK CONTROLLER UPGRADE:
      The RQDX1 5 1/4" disk controller used in  MicroVAX  I  systems  must  be
      removed  and  replaced  with  the  RQDX2  controller.   This  upgrade is
      necessary because the RQDX2 provides features not available on the RQDX1
      and because the RQDX1 is incompatible with the MicroVAX II.

      The RQDX1 does not pass the interrupt acknowledge (IACK)  or  DMA  grant
      signal  (DMGO)  to  other  modules  which may be located after it in the
      backplane.  Therefore it must always be the last  module  in  a  system.
      This  restriction  has been removed with the RQDX2, which does pass both
      of those signals.

      Both RQDX modules are capable of controlling 4 logical  units.   However
      the  RQDX1  can only control a maximum of 2 fixed winchesters (RD5n type
      drives).  Therefore the largest amount of storage that can be  connected
      to  an  RQDX1  would be a combination of 2 RD5n type drives and an RX50,
      which counts as two logical units because it actually handles two  400KB
      floppies.   The  RQDX2 also controls 4 logical units but it knows how to
      control any combination of RDs and RX50s.  Therefore the maximum  amount
      of  storage  that  can  be connected to an RQDX2 would be four RD5n type
      drives.

      The RQDX1 is compatible with RX50 floppies (800KB), RD51 (11MB) and RD52
      (31MB)  disk  drives.   The RQDX2 is compatible with those drives but is
      also capable of controlling RD53 (71MB) drives.


      THE CABINET KIT UPGRADE:
      The MicroVAX I  cabinet  kit  is  incompatible  with  the  MicroVAX  II,
      therefore  the  cabinet  kit  used in the MicroVAX II, BA23 based system
      must be used.  The part number is CK-KA630-AB.

      Both cabinet kits have one serial line connector in order to communicate
      with  the  VAX  console  device.   The  MicroVAX  I cabinet kit uses the
      standard  25-pin,  D-subminiature  RS232  connector.   The  MicroVAX  II
      cabinet  kit  uses  a  different  type  of  connector.   It  is  a 9-pin
      D-subminiature connector and will therefore require  a  different  cable
      from  the  patch  panel to the console device.  The appropriate cable is
      part number BCC08.


      OPERATING SYSTEM UPGRADE:
      Once the hardware has been upgraded it is also  necessary  to  have  the
      appropriate system software which will support the MicroVAX II.  Table 3
      lists the initial versions of  MicroVMS,  ULTRIX-32m  and  VAXELN  which
      support the MicroVAX II.

      Table 3 - System Software Support

      +-----------------+----------------------------------+
      | System Software | Version with MicroVAX II Support |
      +-----------------+----------------------------------+
      | MicroVMS        |         V4.1m or later           |
      | ULTRIX-32m      |         V1.1  or later           |
      | VAXELN          |         V2.0  or later           |
      +-----------------+----------------------------------+

                                                                Page 4


      Many software layered products support the  MicroVAX  II.   Consult  the
      appropriate  Software Product Description (SPD) to verify if the current
      version of the layered product is supported.


      UPGRADE EXAMPLE:
      The following example illustrates the  changes  made  to  a  MicroVAX  I
      system  to  upgrade  it to a MicroVAX II system.  The diagrams represent
      the modules placed in the BA23 backplane.

      Both systems have a CPU, 2MB of  memory,  a  DHV11  8-line  asynchronous
      multiplexer,  a  DEQNA  Ethernet  controller  and  an  RQDX  5 1/4" disk
      controller.

             MicroVAX I System                         MicroVAX II System

          +---------------------+                   +---------------------+
        1 | KD32 CPU - MCT      |                 1 |       KA630-AA      |
          +---------------------+                   +----------+----------+    
        2 | KD32 CPU - DAP      |                 2 |   DEQNA  | MS630-AA |
          +---------------------+                   +----------+----------+
        3 |    MSV11-QA (1MB)   |                 3 |        RQDX2        |
          +---------------------+                   +---------------------+
        4 |    MSV11-QA (1MB)   |                 4 |        DHV11        |
          +---------------------+                   +---------------------+
        5 |        DHV11        |                 5 |                     |
          +----------+----------+                   +---------------------+
        6 |   DEQNA  |   G7272  |                 6 |                     |
          +----------+----------+                   +---------------------+
        7 |        RQDX1        |                 7 |                     |
          +---------------------+                   +---------------------+
        8 |                     |                 8 |                     |
          +---------------------+                   +---------------------+

      Comments:

      The 2 modules of the MicroVAX I CPU  and  the  two  quad  memory  boards
      (MSV11-QAs) were replaced by the KA630-AA and one MS630-AA.

      The DHV11 and DEQNA are compatible with both processors, therefore  they
      were not replaced and remained in the system.

      The RQDX1 controller is incompatible with the MicroVAX II, therefore  it
      is  replaced with the RQDX2.  Any 5 1/4" disk (RX50, RD51 and RD52) used
      on the MicroVAX I is compatible with the RQDX2 on the MicroVAX II.

      The RQDX1 controller must occupy the last slot in a system.   The  RQDX2
      controller  is  located  before  the  DHV11  in  the  upgraded system to
      emphasize the point that it is not required to be the last module in the
      system.

      The MicroVAX I system required a G7272 grant continuity card in  slot  6
      in  order  to  make the system work properly.  This was not necessary in
      the upgraded MicroVAX II system because there was an  empty  dual-height
      slot  next  to  the  MS630-AA memory module.  This illustrates the point

                                                                Page 5


      that the dual height slot next to an MS630-AA is a valid Q-bus slot  and
      can be occupied by any compatible, dual-height option.

      The cabinet kits for the two systems are not shown in the diagrams,  but
      the  one used for the MicroVAX I must be replaced by the cabinet kit for
      the MicroVAX II, part number CK-KA630-AB.  The serial  line  cable  from
      the  patch  panel  to  the  terminal must also change.  The cable of the
      MicroVAX I system must be replaced by a BCC08 cable.

