Re: [Gnome-print] Re: [Gimp-print-devel] An introduction to gnome-print (fwd)

[Michael Sweet <mike easysw com>]

Chema Celorio wrote:
> ...
> Ghostscript drivers as well as other printer drivers can only
> talk raster data to PCL printers. And in this scenario, with a

Not quite true - the PCL 6 driver (which is a *vector* driver)
doesn't have this limitation, and FWIW all HP printers that support
PCL 6 also support PostScript.

> printer that is doing 36 ppm, we can't print at 600 dpi's because
> of the bottle neck between the printer and the print server.

Well, it depends on what you are sending and if you have a fast
interface, such as a JetDirect.  A typical page of compressed PCL
data at 600 DPI runs about 100k (text, line art, etc.)  For a typical
PC parallel port, you'll be stuck printing 2-3ppm.  A 10baseT
JetDirect will increase this to 5-6ppm, while the 100baseT JetDirect
will run at full speed (assuming your computer can keep up)

> The only way I see that we can talk to a printer at this
> speed (and quality ), is if we download whatever font we need and
> then send data as vectors (goto's, lines, text).

That's what the PCL 6 driver is good for, and most fast printers
seem to support PCL 6 and/or PostScript.

> On the other hand, it doesn't make sense to develop a PCL driver
> that translates from Postscript to PCL, since it will be very
> hard to have full Postcript support. I am thinking of
> "for loops" and complex definitions of definitions of definitions,
> plus the parsing involved.

Ghostscript

> I make such a big issue out of this, because I can't imagine
> an office with this problem using Linux. I haven't made any
> tests yet to meassure the speed problems this creates, but we
> need to be able to support this scenario at the optimal speed.

1. These printers have network interfaces without the typical
   bottlenecks seen with parallel ports.  Some also support USB,
   which is similar in speed to a 10baseT interface.

2. Sending raw print data prevents administrators from doing
   accurate accounting, quotas, billing, etc.

3. Building drivers into GNOME applications does not help non-
   GNOME applications.

> Even some apps that send raster data to the printer in the
> Windows world, can't be used at medium or high speed;
> ie Adobe Acrobat Reader. My HP LJ 6P stopps between
> each page because of this when using AAR.

Ah, but then you're using a parallel interface.  FWIW, you may
see better results by setting your parallel port to ECP or EPP
mode in the BIOS setup.

-- 
______________________________________________________________________
Michael Sweet, Easy Software Products                  mike@easysw.com
Printing Software for UNIX                       http://www.easysw.com