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                                                24 July 2004.  SMS.

      DEQNA Jumper Settings


   The DEQNA (M7504) is a Q-bus Ethernet adapter.  The usual cabinet kit
provides a 10Base5 (AUI) connector.

   The DEQNA is obsolete (even by Q-bus standards), troublesome, and not
supported by VMS since about V5.4.  A compatible card, the DELQA,
replaces the DEQNA.


   Jumper W1 sets the CSR address.
      Right two pins: CSR = 17774440  (Default)
      Left two pins:  CSR = 17774460

   Jumper W2 controls a fair-access timer which provides a delay before
   re-requesting the Q-bus.
      Installed: No fair-access wait
      Removed:   5 microsecond fair-access wait  (Default)

   Jumper W3 disables the sanity timer.
      Installed: Sanity timer disabled  (Default)
      Removed:   Sanity timer enabled


      Jumper Locations:

                                                    \     /
      | \           J1           /                                   |
      |  | (Ethernet connector) |                                    |
      |  +----------------------+                                    |
      |                                                              |
      |                            o o-o                      o-o    |
      |                              W1                       W3     |
      |                                                              |
     --------------------------------,                               |
      |                             /                                |
      |                            '-----------------------------------
      |                                                              |
      |                                                              |
      |                               o o                            |
      |                               W2                             |
      |                                                              |
       |                         +--------+                         |
       |                         |        |                         |
       |                         |        |                         |
       +-------------------------+        +-------------------------+


   In SYSGEN CONFIGURE for a DEQNA, specify device "QNA".

DEQNA Problems (from "VMS Version 5.4 Release Notes")

3.23.3 DEQNA Ethernet Adapter May Receive Corrupt Data

Under certain rare circumstances, the DEQNA Ethernet adapter in large and complex Ethernet configurations may receive corrupted data. The VMS operating system automatically enables a data integrity feature that reduces the risk to VAXcluster users. Digital recommends that this feature remain enabled on all VAXcluster members that use DEQNA devices.

The DECnet command COPY provides data integrity checking. User-written applications performing data transfers to systems using DEQNA adapters must provide their own data integrity checking.

VMS support for the DEQNA (from "Cover Letter for VMS[TM] Version 5.5")

DEQNA Support

As of VMS Version 5.4-3, VAXcluster software did not support the DEQNA[TM] Q-bus to Ethernet adapter. If a node in your VAXcluster is connected through a DEQNA device, you must replace the DEQNA with a DELQA or a DESQA before updating to VMS Version 5.4-3 or upgrading to VMS Version 5.5. Contact your Digital representative for information about the DEQNA upgrade program.

VMS Version 5.5 withdraws support for the DEQNA device, except for access using the QIO or ALTSTART interfaces. Within 18 months a release of the VMS operating system will withdraw all support for the DEQNA; after you install that future release, the Ethernet driver will place the DEQNA device in an OFFLINE state, rendering it inoperative.

Follow this link to more Q-bus material.

© 2023 Steven M. Schweda.