M7516 DELQA - Ethernet Interface

The DELQA (M7516) is a dual width Q-Bus Ethernet controller found in most Q-bus based MicroVAXen. This controller is designed to connect to a "cabinet kit" that mounts in the back panel of a BA23 or BA123 cabinet. Sometimes they were used in BA2xx series cabinets with a special S-box handle that connected to the card. Later the DESQA came out that has the S-box handle built on to the card as a single unit.

Switch/Jumper Settings

The DELQA has a five switches in the upper right corner of the board, it has no jumpers. These switches control the following things:

Switch 1 - DELQA Base Address

CLOSED 17744408
OPEN 17744608

Switch 2 - Reserved

Switch 3 & 4 - Mode and Option

Mode

S3
Position

 Option

S4
Position
 Normal  CLOSED   Remote Boot DISABLED   CLOSED 
 Remote Boot ENABLED  OPEN
 DEQNA-Lock  OPEN  Sanity Timer DISABLED  CLOSED 
 Sanity Timer ENABLED  OPEN

"Remote Boot" is a facility where you can send a MOP packet to your VAX and it will reboot. Its kind of handy if you're trying to debug it from a different room, but its downright dangerous to leave on if there are malicious users around. There are also indications in the manual that you can call up a console on the DELQA using the MOP console protocol but it isn't clearly described if that is a test console on the card or if it actually gives you the VAX's console. More investigation needs to be done.

The "Sanity Timer" is a watch dog timer that can be used to reset the VAX if the software hasn't told the DELQA board that it is still running.  These days this is called a Watchdog Timer, when the board is set with this enabled you VAX will periodically reset itself! 

Switch 5 - Reserved

Connector Pinout

The DELQA card has a 20 pin keyed connector on the top left portion of the board. The pins are connected at follows:

  1. Power (+12V)
  2. Key (No Connection)
  3. +12V Return
  4. +12V Return
  5. Ground
  6. Receive +
  7. Receive -
  8. Ground
  9. Ground
  10. Transmit +
  11. Transmit -
  12. Ground
  13. Ground
  14. Collision +
  15. Collision -
  16. Ground
  17. No Connect
  18. No Connect
  19. No Connect
  20. FUSE OK

LED Indicators

The LEDs on the DELQA are numbered 1 to 3 with number 1 being closest to the 20 pin IDC connector on the boards top edge. When the power is applied the LEDs go through the following sequence:

ON-ON-ON Initial Power-On (note that if the board is configured in "DEQNA Lock" mode all the LEDs simply stay on from power up.
ON-OFF-OFF Executing Internal logic self test
ON-ON-OFF Self test executing external loop-back test
ON-ON-ON Ready

Flashing LEDs indicate an error of some sort.

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