DRB32-W driver for DECsystem 5820 under Ultrix 4.0?

[Michel Fingerhut]

Hello world,

We have a DRB32-W (for BI bus, emulates a DR11-W, used to connect
DACs/ADCs), a DECsystem 5820 and Ultrix 4.0.  What we need is the
appropriate device driver.  Although there is one under VMS, there is
none under Ultrix, even 4.0.  Moreover, there is no documentation (that
I know of) on how to write a device driver for DECsystems under
Ultrix.

Can anyone help?  Thx in advance.
Michael