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PPA Printer-Support RPM Packages for Red Hat Linux and Compatible Distributions
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PPA Printer-Support RPM Packages for Red Hat Linux and Compatible Distributions
v0.27, Nov 11, 2000
Information and installation instructions
to accompany pnm2ppa packages for Red Hat Linux available at
http://sourceforge.net/projects/pnm2ppa
(Updated for pnm2ppa-1.04 and later.)
See the "Troubleshooting" section at the end of
this document for
fixes to some reported problems
Overview of HP's PPA DeskJet Printers.
Most of Hewlett-Packard's DeskJet(tm) printers use the PCL3 command language,
and are currently supported by Ghostscript drivers. However, a few models,
namely
- DeskJet 710C Series: HP DeskJet 710C, 712C
- DeskJet 720C Series: HP DeskJet 720C, 722C
- DeskJet 820C Series: HP DeskJet 820Cxi, 820Cse
(discontinued)
- DeskJet 1000C Series: HP DeskJet 1000Cxi, 1000Cse
(discontinued)
feature "Host-based" printing,
and use HP's proprietary
PPA (Printer Performance Architecture) protocol,
instead of PCL. The two models in each series are physically
identical;
they just come with different bundled Windows software.
The 820C and 1000C series are discontinued at this time (January 2000).
PPA printers rely on software running on the
host CPU to carry out the low-level processing
of printer output that would be done by hardware in
a standard PCL printer. The relation of PPA printers to PCL printers
is analogous to the relation between "Winmodems" and true modems.
Unfortunately, HP only supplies Windows software drivers for PPA printers,
and have indicated that it is unlikely that
they will ever make the proprietary PPA specs public.
This is apparently because of concerns that
publication of the specs might reveal crucial details
of HP's trade secrets about "color science" to competitors.
(A secondary issue
is that it is apparently possible to physically
damage the printer by sending it
bad sequences of PPA commands, which is not the case for PCL commands,
and it seems that HP do not wish to take any responsibility for such damage by
encouraging unofficial PPA programming.)
In fact,
the decline in hardware component prices has meant that the anticipated
cost-savings through using host-based PPA instead of printer-based PCL
are less than expected, and two of the PPA printer series
(820C, 1000C) have been phased out, and replaced by similar PCL printers
in HP's product line. The 710C and 720C series are still being sold
at this time of writing. All other currently-offered
DeskJet models appear to be standard PCL3
printers.
Many Linux users may have inadvertently purchased PPA DeskJet models,
mistaking them for PCL3 DeskJets, for which independently-produced
Linux drivers have long
been available. Fortunately, a reverse engineering effort,
started in 1998 by Tim Norman,
http://www.normsoft.com/ppa
and
http://pnm2ppa.sourceforge.net,
and continued by the pnm2ppa project at
http://sourceforge.net/projects/pnm2ppa
has managed to produce drivers that provide basic printing
functionality for these PPA printers under Linux and other
Unices.
The pnm2ppa driver for color printing with PPA printers.
Color printing with PPA printers is supported by the
pnm2ppa driver which is the successor to the older
black-and-white-only driver
pbm2ppa-0.8.6 developed by Tim Norman.
pnm2ppa
can translate portable anymap (pnm)
format images into a stream of PPA instructions which can be sent to the
printer. In the driver name,
"pnm" stands for the superset
of three image formats:
ppm (portable "pixmap" format for color images),
pgm (portable "greymap" format for greyscale images),
and pbm (portable "bitmap" format for black and white images).
Ghostscript has a number of "output devices" that
produce pnm format output from postscript or pdf input.
These come in plain (text) and raw
(binary) variants. While pnm2ppa can now interpret
both plain and raw pnm formats, there is no point in using the
inefficient plain formats: always use the "raw"
output devices, which are:
- ppmraw - raw pixmap format (color images);
- pgmraw - raw greymap format (greyscale images);
- pbmraw - raw bitmap format (black and white images);
- pnmraw - selects between ppm, pgm, and pbm raw formats;
- pgnmraw - selects between pgm and pbm raw formats.
The last two output devices are switches that try to analyze the
image, and select an appropriate format; however, they are not
recommended for routine use, as they may inconsistently choose the format.
The ghostscript-5.10
package supplied with Red Hat 6.x distributions provides all these
devices; older versions may not. To see the list of available
ghostscript output devices, type the command line
gs --help
if the required ppmraw or
pbmraw devices are not shown, you will have to upgrade your
version of ghostscript.
The data must be streamed directly from ghostscript to
pnm2ppa to the (local) printer without being
stored in any intermediate
file: one ppm-format (color) US Letter size page is represented
by 3x5100x6600 Bytes (100MB) in binary format and four times this amount in
text format.
An example of
a command line for printing a postscript
file file.ps using gs (ghostscript) and pnm2ppa is
cat file.ps | gs -q -sDEVICE=ppmraw -r600 -sPAPERSIZE=letter -dNOPAUSE \
-sOutputFile=- - | pnm2ppa --eco -v 720 -i - -o - | lpr -l
(all on a single line). In this example the paper size is explicitly
given to gs as US Letter
(8.5"x11") size
(letter); pnm2ppa no longer needs to be told what
the paper size is, and will read it from the gs output (and check
that it is a permitted size for the printer type).
The pnm2ppa option --eco specifies "EconoFast"
mode, for a lower quality output which uses less ink, and prints faster,
and -v 720 specifies the PPA printer as belonging
to the DeskJet 720C series.
Obviously, it would be impractical to type such a command each time
one wished to print something, so in addition to the pnm2ppa
driver itself, an enhanced version of Red Hat's rhs-printfilters
RPM package is provided; after this is installed, the PPA printer
can be managed like other standard printers with the Red Hat
printtool utility. The postscript file can then be printed with
the simple command
lpr file.ps
- However, if you wish to print to paper sizes supported by ghostscript,
but not supported by the Red Hat
printtool utility, you can
use scripts like the one above.
The HP 710C, 720C, and 820C series support paper sizes from
3"x3" to 8.5"x14", while the 1000C
supports 4"x6" to 13"x19".
Available RPM packages.
A RPM package for pnm2ppa is part of the Red Hat Linux
distribution starting with Red Hat 6.2.
You will also find a RPM package for the latest release of
pnm2ppa
at
http://sourceforge.net/projects/pnm2ppa.
The latest version at the time
of writing is
pnm2ppa-1.04-1.i386.rpm, and is built on
Red Hat 6.2. If you are running a different release
of Red Hat (or a different Linux distribution)
you may need to download and rebuild the source RPM
pnm2ppa-1.04-1.src.rpm instead:
rpm --rebuild pnm2ppa-1.04-1.src.rpm
(You must be root to do this, and have the necessary
compilers installed; on Red Hat, the rebuilt binary RPM will be created in
the directory /usr/src/redhat/RPMS/i386/.)
Red Hat 6.2 and later also includes support for configuring your
printer to use pnm2ppa using printtool
and rhs-printfilters.
If you are using Red Hat 6.1 and earlier,you will need to
update the rhs-printfilters that came with the distribution
to the
rhs-printfilters-1.57-4ppa4.i386.rpm also available at
http://sourceforge.net/projects/pnm2ppa.
(This is designed to work only with printtool-3.43 and earlier.)
Note: If you are using Red Hat 6.2, you may wish to update the
print filter support that it comes with. The pnm2ppa-1.04-1
RPM package supplies the necessary files that you can use.
After installing this RPM, see
/usr/lib/rhs/rhs-printfilters/README.ppa for details.
Installing the pnm2ppa RPM package and setting up the PPA printer.
To install the RPM package, you must log in as the system administrator,
root.
Now begin the installation. First install the pnm2ppa RPM:
rpm -Uvh pnm2ppa-1.04-1.i386.rpm
The pnm2ppa executable gets installed in /usr/bin/.
If you are using a 2.2.x kernel,
(e.g. Red Hat 6.x)
it will be able to autodetect
IEEE-1284 devices like PPA printers, provided they are attached
to the parallel port with a bidirectional IEEE-1284 cable. (If your
printer works under Windows, you have the correct cable.)
(Note that older (2.0.x) kernels do not have this autoprobe facility.)
A script detect_ppa is provided by the pnm2ppa
RPM: just type
detect_ppa
to confirm that your Printer is found.
It is possible (especially on Red Hat 6.1) that you will have to add
a line
alias parport_lowlevel parport_pc
to the file /etc/conf.modules for the printer to be found (this is
a parallel port recognition issue, not specific to PPA printers.
and a known "gotcha" on Red Hat 6.1).
A typical message from the printer, which will
be displayed if autodetection is successful, is:
CLASS:PRINTER;
MODEL:DESKJET 820C;
MANUFACTURER:HEWLETT-PACKARD;
DESCRIPTION:Hewlett-Packard DeskJet 820C;
COMMAND SET:SCP,VLINK;
A list of PPA printers found, and the parallel ports to which they are
attached, will also be shown.
At this point it is useful to test that your printer is working, by
printing a test page using the supplied script test_ppa
which the RPM has installed. You will need to know your
printer model (710, 712, 720, 722, 820, 1000), your paper size
(letter, legal, a4) and the printer port the printer is attached to.
If it is attached to the primary parallel port, this is
/dev/lp1 under older 2.0.x kernels, and (usually)
/dev/lp0 under newer 2.2.x kernels, as in Red Hat 6.x.
Type
test_ppa
and give the details about printer model. papersize, and port number
when prompted.
You will then be asked
whether to print a test page, an offset calibration
page, or an alignment calibration page, etc.
- Tip:
The
test_ppa script
does not use the print filters that
will be installed by the rhs-printfilters RPM, so it is
useful when troubleshooting, for testing if any printing problems are
associated with the basic printer installation, or with the
configuration of the print filters.
Installing the PPA-enhanced rhs-printfilters RPM package (if needed).
- This step is NOT needed on Red Hat 6.2 or later.
The rhs-printfilters rpm distributed with
Red Hat 6.1 does not support pnm2ppa,
If you use an older distribution, you will first have to replace their
rhs-printfilters RPM with the PPA-enhanced version from the
pnm2ppa project.
Once you have confirmed you have a working printer, install the
RPM rhs-printfilters-1.57-4ppa4.i386.rpm
rpm -Uvh rhs-printfilters-1.57-4ppa4.i386.rpm
Configuring the print filters with printtool.
Now start the "Red Hat Linux Print System Manager"
(as root) to
configure the printer, either
by clicking on the printer icon in Red Hat's "control-panel", or just
typing
printtool
In the Print System Manager window, click on Add, then
in the "Add a Printer Entry", select Local Printer, and
click Ok. Hopefully, the port on which the printer is attached
will be listed as "Detected" (if not,
fix the problem before continuing, perhaps by
adding the line "alias parport_lowlevel parport_pc"
to /etc/conf.modules), as mentioned above.
You will now have to "edit
the local printer entry" for the PPA printer. Click on
Select to chose the "Input filter".
The Configure Filter screen will open.
Among the many printer entries in the list
"Printer Type", you should find three entries
- HP DeskJet 1000 series (PPA) (for 1000Cse, 1000Cxi models)
- HP DeskJet 710/720 series (PPA) (for 710C, 712C, 720C, 722C models)
- HP DeskJet 820 series (PPA) (for 820Cse, 820Cxi models)
- If these entries do not show up, it may be because the older
rhs-printfilters package that you updated did not allow
the printer database /usr/lib/rhs/rhs-printfilters/printerdb
to be replaced. Try deleting or renaming the printerdb
file, and then reinstall
the PPA-enhanced rhs-printfilters RPM using
"rpm --force -Uvh rhs-printfilters*"
Select the appropriate
entry for your printer model. You will then be presented with
various options:
- The Driver Description box contains information about the
driver (you may have to use the scrollbar at the right of the box
to read it all).
- The resolution box shows a single
resolution (600x600). There are no other choices.
- The Paper Size box allows
various choices (only letter, legal, and a4
seem correspond to native paper sizes printed by the Red Hat print filters;
the other choices, (a3, ledger, ...) appear to get resized by
the print filters to print on US Letter size paper (?) ).
(Other paper sizes cannot be selected this way, but you can
print to any papersize, if it supported by both ghostscript
and the printer, using a script, as described above, that bypasses
the RedHat printfilters.)
- The Color Depth/ Uniprint Mode box allows various selections
of color and print quality (These are achieved by
using various combinations
of the
pnm2ppa options
--eco (EconoFast mode), -p (disable black
ink cartridge) and --bw (black and white printing only),
without direct intervention by the user.) The choices (in the
most recent printerdb database) are:
- Black and White, econofast mode (
--bw --eco)
- Black and White, normal quality (
--bw)
- Color, econofast mode (
--eco --fd)
- Color, normal quality (
--eco)
- Color, high quality
- Color, normal quality, black ink disabled (
-p --eco)
- Color, high quality, black ink disabled (
-p --uni)
(These are the choices that will be presented by "official"
rhs-printfilters-1.72; if you installed a pnm2ppa
RPM package from
the SourceForge pnm2ppa site, you may have a file
/usr/lib/rhs/rhs-printfilters/README.ppa explaining how to modify
earlier versions of rhs-printfilters to show these updated
choices.)
You may also see a choice to use the older "Legacy"
driver pbm2ppa (black and white only); this is
is stable but unmaintained; it may still be a useful
alternative to pnm2ppa on older, slower systems with
less available memory.
- The three Printing options are not relevant here, and
should not be selected. They are for direct printing
of text (ascii) to non-postscript printers, but since the only way of printing
text files with
pnm2ppa is
by first converting them to postscript(tm), this is not
possible on the PPA printer.
- It is important that the choice
"Fast text printing (non-PS printers only)" is NOT selected,
so that the print filters will
convert text files to postscript before printing.
- The Margins
entries control the margins used when printing text files
(these are instructions to the text-to-postscript
conversion process).
- The Extra GS options box is not only a place for adding
options for ghostscript, but also for the PPA drivers.
Leave this box empty unless you know what you are doing.
As explained in the text in the Driver Description box
(you did read it, didn't you ?), the entry should be in the format:
gs_options PPA ppa_options
Anything before the
"PPA" is interpreted as a gs option, anything after it
is interpreted as a ppa option. You can learn about
pnm2ppa options by typing either "man pnm2ppa"
or "pnm2ppa --help" at a command line (hopefully, these
two sources of information will be consistent with each other!);
When you have made your choices, click on Ok to
save your selections and close the "Configure Filter" screen,
and then click on OK to close the "Edit Local Printer Entry"
screen.
You are now back in the "Red Hat Print System Manager" screen;
highlight the printer you just configured, and, in the Tests
menu, choose Print Postscript test page to print a test page using
the Red Hat print filters. If this printed correctly, your
print system is set up to use the PPA printer, just like any of the other
printers that the Red Hat print filters support.
Configuring pnm2ppa.conf and calibrating the printer.
A number of printer parameters are set to reasonable default values
for each of the printer models, but you may wish to "fine tune"
or calibrate your printer. The default values can be overridden
by entries in the configuration files, which by default are
/etc/pnm2ppa.conf and /etc/pbm2ppa.conf.
At 600dpi, one pixel is 1/600 inch.
The user-adjustable parameters are:
- verbose 1 and silent 1. These control
messages about progress and errors from
pnm2ppa. By default,
messages are sent to the system log /var/log/messages.
The verbose 1 keyword send copies to stderr, the
standard error stream to the terminal. The silent 1
keyword silences the stream of messages to the system log.
- The system log messages may be silenced in the default
configuration file; switch off "silent"
mode with "silent 0" for debugging printer
problems (or use verbose mode).
- The version keyword can be used to specify
the printer model as 710, 712, 720, 722, 820, or 1000.
It is not needed if you use the RedHat printool to
configure the printer.
- xoffset and yoffset: the x-offset and y-offset
(in pixels) of the
printed image on the page, which should be chosen so the image
is correctly centered on the paper. (These can also be set with
the
-x <xoff> and -y <yoff> options.)
See
CALIBRATION.html (or CALIBRATION.txt) for more information.
- topmargin, bottommargin, leftmargin,
rightmargin: the four
margins, which define the distances (in pixels)
from the edges of the paper to the
printed region; parts of the image that are outside these margins
will not be printed.
(These can also be set with the
-t <top margin> ,
-b <bottom margin> ,
-l <left margin> , and
-r <right margin>
options.)
- ColOffsX and ColOffsY: the x-offset and y-offset
(in pixels)
between the color image produced by the color ink printer head, and that
produced by the black ink printer head.
These should be recalibrated
each time an ink cartridge is replaced.
See
CALIBRATION.html (or CALIBRATION.txt) for more information.
- blackshear and colorshear: these are x offsets
between right-to-left and left-to-right sweeps of the print head, one for
the black printing and one for the color printing. These provide sideways
offsets (in pixels) of the right-to-left sweeps,
that can be used to correct "shearing" when printing
in modes that use bidirectional print head sweeps.
- unimode 1 will make unidirectional
print sweeps (left-to-right) the default, instead
of bidirectional sweeps. The
--uni
and --bi options can control how a particular print
run is printed. Unidirectional printing is only useful
(it is slower) if there are issues of "shearing"
in high quality image printing.
- blackness : this takes values 0,1,2,3 or 4 drops of
black ink per pixel, and controls black ink density in black-and-white
and "text-like" black regions in color printing. At present,
this has no effect on printing with the black ink cartridge disabled,
or on black regions identified as "image-like". (This can
also be set with the
-B <n> option,
where n is the number of drops.)
- GammaR, GammaG, and GammaB:
the are the three "gamma" parameters that define the
standard color correction
curves for red, green, and blue. Changing these will affect how
colors appear (decreasing any Gamma enhaces the corresponding color).
The Gamma values are specified as decimal numbers,
with Gamma = 1.0 corresponding to no color correction.
- Gamma values can also be specified using integer numbers
RedGammaIdx, GreenGammaIdx, BlueGammaIdx;
These are determined by a procedure discussed in
COLOR.html or COLOR.txt,
which involves printing a test page. The papersize
keyword specifies the paper size used for this testpage,
because it is produced by
pnm2ppa without the input that
usually specifies the page size.
- The keywords
black_ink 0,
color_ink 0,
cyan_ink 0,
magenta_ink 0,
and yellow_ink 0
can be used to switch of the various inks; this can be useful
in troubleshooting and debugging
pnm2ppa.
Use test_ppa to print various test pages
or calibration patterns to adjust the offsets.
If you wish to specify these
parameters using the command-line options
described above, some of them can be
entered in the "extra GS options" box using the Print System Manager
(printtool), as described above.
Utility programs for the printer.
HP's Windows software provides a utility program
that sends PPA commands to tell the printer to perform
taks like cleaning the printheads, etc. The codes for some
of these functions have already been reverse engineered.
There are proposals to add support for PPA printers to the
PUP (Printer Utility Program) utility, which is
also a project at
http://www.sourceforge.net.
However, as of the time of writing, no PUP support
for PPA printers is available (volunteers, anyone?).
Troubleshooting
The first thing to do is to look at the messages from pnm2ppa
in the system log to see what is happening, whether pnm2ppa
actually received any input, and if it was valid.
(You may need to enable system log messages in
/etc/pnm2ppa.conf, see above.)
Maybe ghostscript failed to convert your postscript file into
PNM format: this is not a pnm2ppa problem!
Here are suggestions for dealing with problems that you may encounter.
- Printing fails in the middle of a print run, perhaps
when a figure embedded in the document is printing (in the latest
pnm2ppa versions, printing finishes normally, but an incomplete
document is printed). The system log
reports that read_line could not read the image, and found EOF
(end-of-file). This probably
means that ghostscript's "ppmraw" or
"pgmraw" output device failed for some reason,
usually leaving a core dump, without completing the
translation of the postscript to a pnm format.
(This has been seen to happen in ghostscript 5.10 ;
upgrading to ghostscript 5.50 solved the problem.) If you cannot
upgrade, try printing the document
in black-and-white using the ghostscript "pbmraw" output device.
- The
test_ppa script works,
but you can't get printtool to make the printfilters work.
You installed pnm2ppa-1.0 and the PPA-enhanced
rhs-printfilters (earlier than v. 1.61) from the pnm2ppa
SourceForge page. You are using printtool v. 3.43 or earlier
and are probably a Mandrake user.
Solution: (a) use printtool to uninstall the PPA printer;
(b) delete (or rename) the printer database
/usr/lib/rhs/rhs-printfilters/printerdb, and reinstall
the rhs-printfilters RPM using the
"rpm --force ... "
option; (c) use printtool to add the
PPA printer again.
(Your previously-installed rhs-printfilters may have
resisted replacement of its printerdb).
- You upgraded your RedHat (or compatible) Linux distribution
and your printfilters no longer work.
You used to use a PPA-enhanced
rhs-printfilters from the
pnm2ppa SourceForge site. You
upgraded your distribution to one using printtool v 3.44 or later
(e.g. RedHat 6.2).
Solution: Make sure that
rhs-printfilters has been updated to a version
1.61 or greater that came with your
upgraded distribution.
Use printtool to delete, and then add the
PPA printer
This will create a new printer configuration compatible
with your upgraded distribution.
- You printed an image file using a "high quality"
printer setting, but it has visible horizontal lines
on it and printing under Windows(tm) 9x doesn't
show this effect (except in "economode").
These are probably "swath boundaries",
showing the junction between different sweeps of the print head.
Solution: using unidirectional printing (PPA option
--uni,
or unimode 1 in /etc/pnm2ppa.conf) helps a little, but
this problem requires an extensive
rewrite of part of pnm2ppa (cutswath.c)
for a satisfactory solution. (Volunteers welcome - see the TODO file in the
pnm2ppa docs (/usr/doc/pnm2ppa*/TODO)!)
- "Flashing light syndrome ".
Your printer usually works, but you have found that some particular
documents cause the printer to fail, and the lights on its panel
start flashing rapidly in sequence. Solution, turn the printer off and back
on again. This is not supposed to happen any more; if it happens
reproducibly, contact the pnm2ppa developers, and offer to
make the offending
file available for testing and diagnosis of this problem.
(Don't sent it to the Mailing List unless requested).
Bug reports can be filed at
the SourceForge pnm2ppa site.
- You wish to print on envelopes or other non-standard media
not supported by the print filters?
Solution: if you can get Ghostscript (
gs) to
produce the correct image, and the paper size is in the range allowed
by your printer, you should be able to do this with a
script that bypasses the print filters, as described earlier
in this document.
- Colors look wrong, or do not match what the Windows(tm) 9x driver
produces. Solution: check that
your color ink cartridge is
not running out of some ink color; if not,
(a) adjust the "gamma"
entries in
/etc/pnm2ppa,conf, or (b)
install a customized color calibration file
/etc/pnm2ppa.gamma. See the file
COLOR.html (or COLOR.txt) for more information.
Contacting the pnm2ppa project.
Send comments or corrections (about this document or the RPMS) to:
ppa-rpms@users.sourceforge.net There are three mailing lists,
ppa.announce (announcements),
ppa.users (users helping users)
and ppa.devel (developers).
You can subscribe to them, or browse their
archives, at
http://pnm2ppa.sourceforge.net/maillist.htm.
To contact the developers, subscribe to ppa.devel and post a message.
There are Public Forums for posting questions
and comments
at
http://sourceforge.net/projects/pnm2ppa
(but whether you get any help from these, depends on
whether anyone is reading them).
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