Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!usc!wuarchive!emory!gatech!prism!dali.gatech.edu!mikeg From: mike@penguin.gatech.edu (Mike Gourlay) Newsgroups: comp.sys.hp Subject: Serial LaserJet printing! Keywords: laserjet serial protocol xon bugs Message-ID: <1990Nov27.111210@dali.gatech.edu> Date: 27 Nov 90 16:12:10 GMT Sender: news@prism.gatech.EDU Reply-To: mike@penguin.gatech.edu (Mike Gourlay) Organization: Georgia Tech Lines: 44 Hi, I connected an HP laserJet Series II to my HPUX 370 serial port using a cable I built to go from the 370's 9 pin RS-232 to the printer's 25 pin RS-232. I created the printer, and when I send stuff to it using lp, the header page gets printed, and part of the first page of the printout, and then the printer drops DTR, give ERROR 22 (protocol error), and the HPUX 370 keeps sending data over the serial line, even though the printer doesn't want it. My guess is that the computer is ignoring the printer's xon/xoff control bytes. The possibilities are that 1) my cable is messed up, 2) the hardware for the RS-232 is messed up, or 3) I've done something stupid in the set-up. Does anybodt have the 9-pin to 25-pin layout? I used: Computer Printer -------- ------- 2 3 RD 3 2 TD 5 7 SIG GND 6 & 8 20 DTR I also tried using the /dev/printer `file' via sleep 999999999 < /dev/printer & stty raw 9600 -parenb cs8 ixon -istrip clocal < /dev/printer and then I cat file >> /dev/printer. What happens then is that more of the file gets printed, but if the printer runs out of memory (hence sending an xoff to the computer) or a page gets form-fed (which also causes the printer to send a ^S to the computer), the computer ignores the ^S (speculation) and so the printer, not wanting any more data, but still receiving data, punts, and drops DTR. Can anyone help me? I hope its the cable. I called the HP LaserJet hotline, and they are completely 100% clueless. They know NOTHING about HPUX. They are only trained on MS-DOS, and they ask me stupid questions. My local HP reps say that what I have should work, but obviously they are wrong. Thanks in advance, Mike