> 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.

All HP printers I have seen support at least IEEE1284 Nibble Mode.
I'm running a modified lpt driver with this mode supported since 1.2
to get the PJL and Postscript messages back.

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


-- 
Juergen Hannken-Illjes - hannken@eis.cs.tu-bs.de - TU Braunschweig (Germany)