SYSRUTH@utorphys.BITNET ("Ruth Milner, Systems Manager x2746") (07/07/88)
We have a setup here where an Apple LaserWriter is connected to a
DZQ11 serial line on a MicroVAX-II. While at VMS V4.5, this setup would
not work unless we reverted to the 4.3 TTDRIVER. This had something
to do with the fact that the 4.5 TTDRIVER could not handle things when
the LaserWriter sent a bunch of <XOFF>s (not just one) on buffer overflow.
(It also doesn't always send an <XON> again afterwards, resulting in a
timeout). The 4.3 TTDRIVER could cope, and everything worked fine.
Recently we upgraded to VMS V4.7, and we find that we now have the
same problem as we originally had at 4.5: if we use the vanilla
VMS print symbiont, with the 4.7 TTDRIVER, nothing prints. We assume
this is because the LaserWriter loses data and therefore quietly
aborts the job. We did get a public domain program which allows us
to print small files, but any job longer than a page, and sometimes
even short files, often aborts with either timeout errors or errors
like "OFFENDING COMMAND: read
- filestream - ..." and then only partially finishes that page.
My question is mostly to do with the TTDRIVERs. What changed in the
4.4/5 TTDRIVER that might have prevented our being able to use it
for this purpose? Besides adding terminal classes, what other changes
were made to the 4.6/7 TTDRIVER? Would we be able to put the 4.3
version back on the system and have it work as it used to under 4.5,
or are the changes at a fundamental enough level that this could cause
VMS to detect an inconsistency and crash?
I am aware of a couple of packages available which may or may not
be suitable; if we can't go back to the 4.3 TTDRIVER then I believe what
we need is a true print symbiont, not just a conversion program for dvi to
PostScript format (which is all the majority of these packages are). If,
however, the 4.3 driver will work, then that is the simplest solution.
Comments, anyone? Ideas? If you are just using the ordinary VMS stuff
to handle your LaserWriter, how did you get it to work? Since some of
the answers might be fairly technical, it might be best to send them
directly to me, and I will summarise to the net if others are interested.
Also, I don't know much about LaserWriters; if what we need is a new
PROM rev., or something, I'd be interested in hearing about that, too.
Thanks, everyone.
Ruth Milner
Systems Manager
University of Toronto Physics
SYSRUTH@UTORPHYS (BITNET)