CAPT Linux driver

(Canon LBP-810, Canon LBP-1120)

By Nicolas Boichat

I don't maintain this driver anymore, please do not contact me about bugs or problems, unless you provide a fix.

Summary

Canon printer using CAPT protocol are GDI printers (or winprinters), using a proprietary and undocumented protocol, that I reverse engineered (see Tools and Techniques).

You can download here a driver for Linux.

You must use an USB cable to connect your printer. If it only has a parallel port, I'm sorry but my driver won't work.

This driver should support both A4 and Letter sized paper, but I only tested it with A4 sized paper.

Download

Version 0.1 (August 17 2004): capt-0.1.tar.gz

Install notes

Follow the instructions presented on the README file in the package.

Supported printers and kernel versions

This driver has been reported to work with these kernel versions and distributions:

Kernel 2.6.7 or greater (Gentoo)

This driver works with these printers:

Canon LBP-810
Canon LBP-1120 (it has been reported to work better than the official Canon drivers)

It should work with other CAPT printers, but it needs to be confirmed.

Unsupported kernel versions

This driver has been reported NOT to work with these kernel versions:

Mandrake 2.6.3-4

Tools and Techniques

Here is the way I followed to write this driver:

I installed the Windows driver on a XP computer, then ran and installed USB Snoop to catch USB transmission. And then followed these steps:

Disconnect the USB Printer cable
Print simple document (only a few points)
Connect the USB cable
Wait for the printer to start its engine

Then wait for the page to print, disconnect the USB cable, copy the log file somewhere else and delete the original.

If you only want to analyse the data sent to the printer before it effectively print the page, which is very useful if you don't want to waste paper and let you analyse the compression protocol, just follow these steps after the printer engine starts:

Disconnect the USB cable
Remove the paper before the printer takes it.
Cancel the current job on Windows
Start to print the next page.

Thanks

Rildo Pragana, for his driver for another GDI winprinter (Samsung ML-85G), on which I based my work, and for his articles which helped me a lot.
My sister, Stéphanie Boichat, who was bored with rebooting on Windows to print her documents, lent me her Canon LBP-810, and gave me the opportunity to do this interesting work.
Emanuele Zattin, who reported that this driver works with the Canon LBP-1120.