VAX Q-bus identical to PDP-11 Q-bus?

Jerry Weiss jsw at
Wed Dec 6 15:36:02 CST 2017

The metal face on the Q-Bus cards was there as part of the solution to meet FCC (or equivalent) regulations to
 reduce electrical interference to radio receivers and other devices.

If you can physically fit it into a older Qbus backplane and sort out the cabling it should work
provided you have the necessary drivers.  

However, I’m not aware of drivers for the M5976 for most PDP/LSI-11 operating systems.  Even for VMS or Ultrix
the card is reported to only support specific DEC hardware, even thought is SCSI controller.  


> On Dec 5, 2017, at 9:16 AM, Aaron Jackson via cctech <cctech at> wrote:
> I'm looking after a VAX 4000 for a friend, which has a SCSI Q-bus card
> (M5976). If the card did not have the large metal face, would it work in
> a Q-bus PDP-11? We are not going to potentially ruin a card by trying
> this, but I am interested to know if this is the case.
> Thanks,
> Aaron.

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