fyl@ssc.UUCP (Phil Hughes) (12/02/88)
Over the past year I have seen many people refer to the problem where the
V/AT spooler stops talking to a printer even though there are files in the
print queue. lpstat shows the printer as idle but queued files exist. I
don't think anyone has ever thought it was anything other than a V/AT bug.
Well, here is an interesting story.
One of our consulting customers has been running V/AT on a clone for over
a year. They had an Centronics printer with parallel interface. This
problem never happened. They just called because of a death of their
printer. I suggested they swipe a printer from their DOS machine to get
things running. They have a Brother printer. When they plugged it in
printing took off.
About 1 hour later they called back. Things had stopped working. An
lpstat showed the old "printer spooler bug" - idle printer but files in
the queue. This is only one data point but it sounds to me like there is
a difference between Centronics and Centronics compatible.
--
Phil Hughes, SSC, Inc. P.O. Box 55549, Seattle, WA 98155 (206)FOR-UNIX
uw-beaver!tikal!ssc!fyl or uunet!pilchuck!ssc!fyl or attmail!ssc!fylbill@zycor.UUCP (bill) (12/05/88)
In article <1559@ssc.UUCP> fyl@ssc.UUCP (Phil Hughes) writes: } I suggested they swipe a printer from their DOS machine to get } things running. They have a Brother printer. When they plugged it in } printing took off. } } About 1 hour later they called back. Things had stopped working. An } lpstat showed the old "printer spooler bug" - idle printer but files in } the queue. This is only one data point but it sounds to me like there is } a difference between Centronics and Centronics compatible. I have a Epson Rx-80 and a Panasonic KX-P3151 for nice output. The Epson works fine. If I plug in the Panasonic instead, the system prints for about 2 minutes then crashes. This is with a Herc graphics card (mono). I have not tried swapping cards yet... In any case, this would lead me to the same conclusion as above - there is some difference between compatible and compatible. -- Bill Mahoney bill@zycor.UUCP Sorry Sen. Bison, but you're no Yacc Kennedy...
dtynan@sultra.UUCP (Der Tynan) (12/06/88)
In article <1559@ssc.UUCP>, fyl@ssc.UUCP (Phil Hughes) writes: > > About 1 hour later they called back. Things had stopped working. An > lpstat showed the old "printer spooler bug" - idle printer but files in > the queue. This is only one data point but it sounds to me like there is > a difference between Centronics and Centronics compatible. > > Phil Hughes, SSC, Inc. P.O. Box 55549, Seattle, WA 98155 (206)FOR-UNIX One thing I would check for, is the printer buffering. A "Centronics" interface is just that. An interface. A lot of older printers don't have any kind of buffering, which means that you have to feed it data at the print rate. This can result in an interrupt-per-character type arrangement, which can kill even the best operating system :-( On newer printers, once you get the interrupt, you can handshake in a lot of chars at once, meaning that the latency is a lot less. It seems to me, that the driver/printer interface is getting confused. This could be a result of heavy interaction. Note however, that I don't use Microport UN*X, so the above is nothing more than idle speculation, given the information posted. Hope it helps... - Der -- dtynan@zorba.Tynan.COM (Dermot Tynan @ Tynan Computers) {apple,mips,pyramid,uunet}!Tynan.COM!dtynan --- If the Law is for the People, then why do we need Lawyers? ---