Claude.P.Cantin@NRC.CA (11/21/90)
This is a printer question. I am trying to connect a DECwriter (yes those 15 year-old teletype things) to a 4D/280S, on port /dev/ttyd56. The printer type I am using is "dumb". BANNER is set to 0. STTYPARAMS has be set to "ixon ixoff", "sane", "-ixany ixon ixoff", and many others, but the same thing happens: Here is the problem: when sending a file to the printer, only the first 8 or 9 lines are printed. The rest is ignored (i.e. not printed). THIS IS NOT RELATED TO THE DECWRITER since a HP Laserjet III, AND a VT220 terminal show EXACTLY the same symptoms. It looks as if the SGI sends only about 255 characters. The cable used is a null modem cable (pins 2 and 3 cross-wired). Could someone point me in the right direction???? Has this happen to anyone else??? What am I doing wrong???? Here is the commands I used to enable the printer: /usr/lib/lpshut /usr/lib/lpadmin -pdecwriter -mdumb -v/dev/ttyd56 (also tried ttyf56) /usr/lib/accept decwriter enable decwriter /usr/lib/lpsched Any suggestions??? Thanks, Claude Cantin (cantin@vm.nrc.ca, CANTIN@NRCVM01.BITNET) National Research Council of Canada Ottawa, Ont. (613) 993 0240
operator@IRIS.KTH.DK (Martin Liversage) (11/21/90)
> I am trying to connect a DECwriter (yes those 15 year-old teletype things) > to a 4D/280S, on port /dev/ttyd56. The printer type I am using is "dumb". > BANNER is set to 0. STTYPARAMS has be set to "ixon ixoff", "sane", > "-ixany ixon ixoff", and many others, but the same thing happens: > > Here is the problem: when sending a file to the printer, only the first > 8 or 9 lines are printed. The rest is ignored (i.e. not printed). Maybe you need to use another device driver. I had the same kind of problem when my HP LaserJet was on port /dev/ttyf2. Then I switched to /dev/ttyd2 and the problem disappeared. There's also a /dev/ttym*, and don't ask me about the differences. These I have utterly forgotten. Martin Liversage Royal Dental College Copenhagen Department of Pediatric Dentistry Norre Alle 20 DK-2200 Kobenhavn N
vjs@rhyolite.wpd.sgi.com (Vernon Schryver) (11/24/90)
All of the minor devices for a given major are handled by the same driver. The ttyd*, ttym*, and ttyf* minors for the 6/8-port (CDSIO) and integral ports differ: ttyd* use pins 2,3, &7. RTS and DTR are high while the port is open ttym* use 2,3,7,8, and 9/20 (9 on the 9-pin connector, 20 on a DB-25). DCD and DTR are used in the standard RS-232 way. An open(2) will not be completed unless NDELAY is set or DCD (pin 8) is tree. DTR is high or true from start of the open until the port is closed. ttyf* use 2,3,4,5,7,8, and 9/20. Beside the standard DCD/DTR dance, output is stopped while CTS is false. In addition, the de facto standard "hardware flow control" use of RTS is done, with RTS low meaning the computer (often the application) is not ready for more input. All of this is documented in chapter 10 of the new (IRIX 3.3 & I think 3.2) "IRIX System Administrator's Guide", Document Version 3.0, Document Number 007-0603-030. Missing output to a printer sounds like missing flow control. One familiar cause is that the device has not been configured to generate flow control signals, either XON/XOFF or a wire. Ancient devices from the 1970's and 1980's often used DSR or DTR for "hardware flow control." I think I remember some (e.g. TI-800's) that optionally used odd pins like 18 for flow control. Creative cabling can be useful in such cases. You can hook pins 2,3, &7 between the device and computer, loop the computer's 8 to its 9, connect the device's flow control signal to the computer's CTS input, and use /dev/ttyf*. A "break out box" is a vital tool for such games. A "Y-cable" and a dumb terminal can make an effective and cheap "line monitor. Vernon Schryver, vjs@sgi.com