[cups.general] cups detection of usb printers
rance at frontiernet.net
rance at frontiernet.net
Thu Jan 31 16:33:18 PST 2008
I have a unique situation that Im not making any headway with, and I
really need help.
I have an old parallel port dot-matix printer that prints on
continuous feed paper, I use it for special logging situations,
banners, and draft printing when my laser toner is running low.
the printer works fine with cups when plugged into parallel port. but
since I have two parallel printers I bought a usb-parallel conversion
cable from Belkin.
the dot-matrix printer worked fine as a usb printer under cups 1.1.x
1.2.x has introduced a problem.
First my OS has detected that a usb printer is installed and has
created a /dev/usb/lpt0 device file with the correct permissions.
under cups 1.1.x that was enough, if the usb backend saw that a usb
lpt device file was present, it would automatically add the usb port
to the list of available connectors when adding a printer.
cups 1.2.x is different somehow but I dont understand exactly how.
cups 1.2.x does not show the usb port available in the connectors list
when adding a new printer.
A google search led me to an article about how the new usb backend
detects the usb print device files and then "tests" them to see if
they are "real" printers or not.
I need help in two areas... first, is this true? does the usb backend
"test" the device to see if its a real usb printer?
and second; If so, what is tested?
Why would a parallel-to-usb cable fail the test? Only thing I can
figure is the printer is so old it can't respond to a particular
status check command that a newer real usb printer might handle ok.
The printer in question is a Panasonic KX-P1124.
I also have a relatively new OKI dot matrix printer (also parallel)
and its doing the same thing.
both printers seem to work when plugged directly into the parallel
port, so it isn't the printers themselves, its the usb backend somehow.
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