DR11-W to Model-1/20 on 4.1 BSD

[romig at osu-dbs.UUCP]

We have a Raster Technologies Model-One/20 frame buffer that I am
*trying* to connect to our Vax 780 (which runs 4.1 BSD) with a DR11-W.
The driver (which I hacked from a DR11-B/W driver that hadn't been
tested with a DR11-W) *seems* to work, although I am not sure.
Oh yeah, the DR11-W is the MDB DR11-W, not the DEC DR11-W.

Specifically, I load the CSR with function bit 3 set, set the GO bit,
and it times out N seconds later.  The function bits appear to get
set correctly, the cables seem to be hooked up correctly, and I'm
really stumped.

(1) Has anyone out there connected a Model One/xxx to a Vax running
    Unix with a DR11-W before?  Can you give me any helpful hints (or
    even software?)

(2) Does anyone out there have any helpful hints on what I can do to 
    find the problem?  General debugging techniques for Unix device
    drivers would be *VERY* much appreciated.  Specific debugging hints
    for DR11-W's would be nice too.  For example, is it possible for me
    to use adb to massage the device registers and force it to do a write
    operation?  Can anyone clue me in on how to do this (ie, what to write
    where...)

Sigh....whimper....

					Steve Romig (614) 422-0915
					cbosgd!osu-dbs!romig (UUCP)
					romig at ohio-state (CSNET)