nerdylorrin.net wiki: CUPS

The Common UNIX Printing System

is a print spooler and a set of support programs for using and administering printers. It's at the core of printing on Linux. Packages like Samba (providing Windows connectivity) and Ghostscript, Foomatic, a2ps (providing support for various printers and document types) orbit around it. A good place to start is the LinuxPrinting.org CUPS Quick Start

Installing CUPS

Ports

For parallel printers make sure /proc/sys/dev/parport/parport0/autoprobe exists. If it doesn't you might be missing either or both of the following in your kernel:
- "Parallel port" section -> Parallel port support -> PC-style hardware -> IEEE 1284 transfer modes (this may not be necessary?)
- "Character Devices" section -> Parallel printer support

Identifying Drivers

Search the linuxprinting.org printer database

to see what drivers you'll need for your printers. I've got a NEC SuperScript 870

and an Epson Stylus C86

The NEC SuperScript 870 uses the ljet2p (HP LaserJet II P) Ghostscript driver. That means it depends on ESP Ghostscript to rasterize incoming PostScript data for the printer.
The Epson Stylus C86 uses the gimp-print driver and is treated as a C84 (same printer, different marketing). Gimp-print comes in various flavors including as a CUPS raster driver and a Ghostscript plug-in. I used the CUPS raster driver.

CUPS software

Install CUPS (apt-get install cups cupsys-bsd)
- CUPS is administered with a web interface. By default only access is allowed from 127.0.0.1. To allow access from other computers remove the Deny From All line in the <Location /> and <Location /admin> blocks of /etc/cups/cupsd.conf. Additionally you'll have to add users you want to allow access to the admin pages to the lpadmin group in /etc/group.
Install the ESP Ghostscript PostScript interpreter if you'll be using a Ghostscript driver (apt-get install gs-esp
Install the CUPS Gimp-Print raster driver if you'll be using a Gimp-Print driver (apt-get install cupsys-driver-gimpprint)

Printer Setup

Install PPDs for your printers. (PPDs are Postscript Printer Definitions; they describe the capabilities of a printer)
- CUPS raster drivers (e.g. Gimp-Print) include necessary PPDs. You're done.
- Normally you can obtain PPDs from the driver website. This is the case for the ljet2p driver.
  - The NEC SuperScript 870 supports 600 dpi but the HP LaserJet IIP only supports 300 dpi. Instructions to modify the PPD to support 600 dpi printing are posted to the linuxprinting.nec.general mailing list. The resulting PPD is attached.
- Place the .ppd in /usr/share/cups/model and restart CUPS (/etc/init.d/cupsys restart)
- Most PPDs from linuxprinting.org depend on Foomatic (apt-get install foomatic-bin)
Configure a printer. Point a web browser at port 631. Login with your Unix login. After entering a name, location, and description, you should be able to select a device (e.g. parallel port #1), and the printer model (assuming drivers were installed correctly). With any luck the test page will print correctly! When selecting a USB printer you should see the name of the printer next to the USB port in the drop-down. If not check /proc/bus/usb/devices to make sure the printer has been detected. (See USB info in Kernel).

Configuring the Margins

Run the following commands:

cd /tmp wget http://www.linuxprinting.org/download/printing/alignmargins wget http://www.linuxprinting.org/download/printing/align.ps chmod 755 alignmargins su ./alignmargins

This will print an alignment page. Text at the top of the page should indicate the currently set Margins and HWMargins. If these aren't all set to 0, enter 0 at every prompt and start over.

The first task is to align the output within the physical page. Measure H and V (in inches) from the edge of the page and calculate x and y as explained on the print out. Enter 0 for all the m* values and the calculated x and y values. My values were -75, 0 for my NEC SuperScript and 0, 0 on my Epson C86. These settings can be manually changed in /etc/cups/ppd/printername.ppd under /Margins[x y]>>setpagedevice

Run alignmargins again. The black arrows should point to the corners of the page. If you printer can't print to the edge of the page they may be clipped.

The next step is to specify how much (in 1/72" inches) is being clipped. On the most recent print out read off ml, mb, mr, and mt by seeing where the grey wedge is clipped on the ruler of the left, bottom, right, and top sides, respectively. These settings can be manually changed in /etc/cups/ppd/printername.ppd under <</.HWMargins [ml mb mr mt].

If you run again the thin black line around the outside of the image should be visible. Since the PPDs have changed any previously configured clients need to be forced to re-aquire them.