You said you have Thinkpad R51 That has a 25 pin parallel port on he back, and your LaserJet4 printer has a Centronics port.
On Fri, Apr 11, 2008 at 4:32 PM, dracon <[EMAIL PROTECTED]> wrote: > George, thanks. > > Since telling Windoze where the printer is was a one time deal, that isn't > a problem on that side. Wish that could be done for Ubuntu. > Parallel cables don't solve my problem of easily switching the printer off > to my laptop either which has no Centronics port. > > Now to cups. I don't think this is really a cups problem but I don't yet > really understand well the relationship between hal and cups. I'm under > the impression that hal runs before cups. It seems that when hal has > found and identified the devices' that exist (even if the identification > is "unknown usb device") then cups is capable 1) of allowing driver to > be assigned to that device/hal port and 2) follow that device if it is > subsequently moved to another usb port between reboots. > > It's only when hal only finds the printer cable (Centronics parallel to > usb cable device) and does not find a printer on the end of the cable > (even a "unknown" printer) that cups does not present that printer for > configuration in the "add Printer" options. That leads me to conclude > that cups is ok but hal is not. > > Now I don't know what hal uses to get the hardware info but from what > I've read hal is pretty low level stuff looking for signals on specific > pins with certain timings...etc. Since hal has found the Cable device I > expect that his timing is PDQ and he doesn't wait a long time for the > end point (printer) of the cable to post a signal....Just guessing here > but if hal moves on to the next port before whatever device is on the > end of that cable sends a "i'm here!", he will not even find a "unknown" > device and assumes that no device exists. At that point cups can't find > a printer to configure since hal tells him there is no device on the > cable. > > Net: I believe this could be a simple timing fix in hal for a coder to > cause hal to wait a millisecond or so for the device at the cable end to > post if he finds a Parallel2usb "Printer" cable device on the port (he > can tell the difference), (but not me! unless I get sufficently bugged > to go back to school -lol- not likely) > > I don't think this is a cups problem...(is problem for me though) If > it's hal this problem will be distribution independent across Linuxes > and while the older HP laserjets may be "older" there are a bunch out > there, and this has more to do with how hal is handling the Parallel > Printer Cable device regardless of manufacturer.. (I lose my HP 890c > inkjet sometimes as well the same exact way...just not as often probably > because it is quicker at responding to it's interface...and I've seen > the problem expressed with Brother, Epson, and other printers of both > technologies in several fora, not just this one. (most end with a null > answer as this one seems to have)) > > Any idea how to get a hal type to take a look at this? I guess Ubuntu > team could champion it but the interest seems low even from the cups > side. Still if Ubuntu is trying to establish itself in the laptop market > where parallel ports are appearing less frequently maybe they should > take a look at this. > > -- > Printer is not detected properly over USB > https://bugs.launchpad.net/bugs/35638 > You received this bug notification because you are a direct subscriber > of the bug. > ** Attachment added: "unnamed" http://launchpadlibrarian.net/13365778/unnamed -- Printer is not detected properly over USB https://bugs.launchpad.net/bugs/35638 You received this bug notification because you are a member of Ubuntu Bugs, which is a direct subscriber. -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
