On Mon, Jan 17, 2000 at 12:43:24PM -0500, Anne Bennett wrote:
> Just over a year ago (on 1999/01/04), Federico Lupi 
> <Federico_Lupi@www.datasys.it> wrote to describe a problem uncannily
> similar to one I have recently experienced:
[One line excerpts for compactness]
> I had a very old Citizen dot matrix printer connected to lpt0 which
> Recently I have substituted it with an HP Deskjet 695C.  I upgraded to
> Printing became very slow both with and without ghostscript: a
> > Finally I changed the driver from lpt0 (interrupt) to lpa0 (polled) in
> > Do you have any idea of what is happening? Why did lpt0 work with the old

The new inkjets tend to have a different idea of what IEEE1284 is supposed
to look like. It is likely that they aren't triggering an interrupt that
the NetBSD driver is looking for - as the trigger to send the next buffer
full of data. The NetBSD box waits until something causes the driver
to wakeup - perhaps a timeout on the printer?

I don't have access to a 1284 tester, so I can't say who's strictly
correct. It certainly would be possible to write an interrupt driven
driver that uses alarms to wake itself up, but I don't know if it
could determine whether it's safe to stuff the buffer again.

> Also, has anyone written a piece of software to nab whatever the
> printer says back to us?  It would be kind of nice to be able to
> report printer error messages and so on.

I'm not aware of any standardized language for parallel printer
error messages. The traditional line signals - ready, paper-out
are already reported by lpd.

HP probably has a proprietary control protocol for reporting errors,
which they would use in their Windows drivers.

-- 
David Maxwell, david@vex.net|david@maxwell.net -->
Any sufficiently advanced Common Sense will seem like magic... 
					      - me