Help: Benson Plotter on 4.2

[parker at NRL-CSS.ARPA]

From:  Alan Parker <parker at NRL-CSS.ARPA>

Is anybody using a Benson (sometimes called Varian) plotter on 4.2?
(I can't believe I'm the only person dumb enough to buy one!)  The
supplied driver on the 4.2 distribution doesn't work at all.   It
generates a large number of unibus errors and NPR timeouts.   

This was also the case with the 4.1 distribution (at least the version
that we got).  Peter Eichenberger @ Stanford gave me a fixed version of
the driver for 4.1 which we have been running for the last few years
without any problems.

I modified this driver for 4.2 as best I could.   It seems to work OK,
until the plotter is taken offline while its printing.   When that
happens, the device goes away.   ("va0: no such device or address").
The only way to get it back is to reboot.   Not acceptable.

So much for where I stand.   Does anyone have any suggestions?  Do *you*
have a Benson plotter running on your system?   If so, I would like to
compare notes.    Thanks.

arpa: parker at nrl-css
uucp: ...!decvax!nrl-css!parker

-Alan