jand@htsa.uucp (Jan Derriks) (04/11/89)
Who can help me with the following problem: Sometimes, when a terminal is switched off and on ca. 25 times (in 2 weeks or so) the /dev/ttyxx line 'hangs'. Nothing else but a reboot of the system helps. An echo >/dev/ttyxx appears on the screen, but I cannot read /dev/ttyxx at all. Fortunately not all tty lines have this problem. In the release notes Sequent mentions a hardware bug in the Systech MTI terminal multiplexor board but has no intention to fix it. Big question is: how can I 'reset' the /dev/tty line like a system reboot does, without actually having to do a complete reboot ? Anybody knows this problem and has an answer: post it or please send to (uucp)..hp4nl!htsa!jand. Thanks. Jan Derriks | AHA-TMF (H.T.S. 'Amsterdam') email: hp4nl!htsa!jand | Europaboulevard 23 phone: +31 20423827 | 1079 PC Amsterdam, The Netherlands
jimd@gssc.UUCP (James DePorter) (04/14/89)
In article <834@htsa.uucp> jand@htsa.uucp (Jan Derriks) writes: >Who can help me with the following problem: > >Sometimes, when a terminal is switched off and on ca. 25 >times (in 2 weeks or so) the /dev/ttyxx line 'hangs'. >Nothing else but a reboot of the system helps. >An echo >/dev/ttyxx appears on the screen, but I cannot >read /dev/ttyxx at all. >Fortunately not all tty lines have this problem. > I have had the same problem, I have f100's hooked to our B8. Two things I noticed is that it happened more with newer users and most of the emacs users. I found that when the emacs users rsh to our vax some of the control codes change for them i.e. ^s would hang them (of course) and they wouldn't be paying attention to the flow control and try to kill everything they were doing to get back working on that port. I have found if you can send the ^q before all of the processes are killed you have better than 90% chance of recovering. The reason I bring up f100's is that they sometimes put garbage onto the line and can hang the terminal. Switching terms off and on can leave the port in the wrong flow control state also. The worst problem is not being able to kill csh as root when someone has flow control stopped. > >Big question is: how can I 'reset' the /dev/tty line like a >system reboot does, without actually having to do a complete reboot ? >Anybody knows this problem and has an answer: post it or please >send to (uucp)..hp4nl!htsa!jand. Thanks. > I haven't found a way once the port is gone. Usually I find an unused port until I can reboot at night (less impact on the local community (-8 ). >Jan Derriks | AHA-TMF (H.T.S. 'Amsterdam') >email: hp4nl!htsa!jand | Europaboulevard 23 >phone: +31 20423827 | 1079 PC Amsterdam, The Netherlands jimd tektronix!sequent!gssc!jimd Not a spokesperson for Sequent, just a satisfied user. Now where is that check for the Symmetry upgrade? I had it here somewhere.... -- "When in doubt, logout" and now a fortune:
pwolfe@kailand.KAI.COM (04/22/89)
>/* Written 7:26 am Apr 20, 1989 by jand@htsa.uucp in kailand:comp.sys.sequent */ >What are annex's and cisco's and what exactly is the price ? The Annex is an ethernet terminal server, sold by Encore Computer Corp. I read somewhere that Encore sold the whole annex works to Systech, but Encore can still sell the Annex. There are two flavors, Annex I and Annex II. We have four Annex I's, which come with 16 serial ports (db9p connectors), one centronics parallel printer port, one ethernet port in (for connecting to your network), and one ethernet port out (for cascading Annexes). When we bought ours (around Dec 1987), they were list priced at $6,000 each (compare that to $4,800 for the 16 port System MTI-1650 from Sequent. The Annex II has 16 or 32 ports (upgradable), but I don't know what they cost. You might check with Systech to see what they are charging. We got ethernet terminal servers because we wanted to place our terminals further from the computers than the direct rs232 ports support, and because they let us login to any host on the network without a/b switches and patch cord changes. When we get a new computer, or one goes down, people no longer scramble for the patch panel to get connected. We have dialin modems connected to one, so we aren't dependant on any host being up for people to dialin. They can be configured to allow multiple logins from a single terminal (you use the break key and "fg" commands to switch from one active session to another). They support rlogin and telnet commands for remote logins. You can have the annex setup to require that user's supply a loginid and password before being given access to the annex command line, or not (we do for dialups, but not for terminals in house). I would recommend Annexes to anyone, but not having much experience with other brands, I can't honestly compare their features. I asked quite a few people, and read some discussions in various netnews groups and at the time, Bridge, Cisco and Encore were all out there, and the Annex was the one there were fewest complaints about. The only problems I've run into is getting any parallel printers to work on the parallel port, getting an Apple Laserwriter to work on any serial port (the LaserWriter talks back, and there's no way I know to get something to read that), and the annex cannot be made a "trusted" host, since Encore made some silly mistakes in their rlogin protocol (when a user types "rlogin host -l otheruser", the annex sends "otheruser" as both the local and remote usernames, no matter when they originally logged on with). Also, it's possible, but really painful to get someone else's UUCP to dialup through an annex. I gave up, as it was much easier to just leave one modem directly connected to a host, and only tell people we uucp with what that phone number is. Patrick Wolfe (pat@kai.com, {uunet,uiucuxc,sequent}!kailand!pat) System Manager, Kuck and Associates, Inc.
loverso@Xylogics.COM (John Robert LoVerso) (04/26/89)
In article <2400042@kailand> pwolfe@kailand.KAI.COM writes: > The Annex is an ethernet terminal server, sold by Encore Computer Corp. I > read somewhere that Encore sold the whole annex works to Systech The product line was sold to and is now being developed and manufactured by Xylogics, Inc. As for some problems he reports: > The only problems I've run into is getting any parallel printers to work on > the parallel port This is something new. The Annex printer port supports a standard centronics interface and shouldn't have problems with parallel printers. I've played with such things as Printronix P600s to HP Laserjets on Annexes with no problems. In additional to the physical interface, the Annex receives printjobs from a host via a BSD-lpd-like spooling protocol. The Annex host tools include two ways of getting BSD-lpd print jobs to an Annex: either through a simple change the lpd sources or by an auxillary print program, which can be used as part of an output filter for a printer. > getting an Apple Laserwriter to work on any serial port > (the LaserWriter talks back, and there's no way I know to get something to > read that) This is true for any Postscript printer, which generally requires a bi-directional interface to pass back status messages. The way to use such a printer is via a reverse-telnet program. This is a daemon that runs on a host, and uses a "pty" to fool the Adobe postscript driver into thinking its got a tty. Such a program ("rtelnet") is provided on with the Annex host tools. A similar program ("annexf") was written by John Sloan of Wright State Univ <jsloan@wright.edu>, for use just as a printer filter. "rtelnet" lets you do other things (like use an Annex port for things like a host "getty", etc). > and the annex cannot be made a "trusted" host, since Encore made > some silly mistakes in their rlogin protocol (when a user types "rlogin host > -l otheruser", the annex sends "otheruser" as both the local and remote > usernames, no matter when they originally logged on with). This is probably true of most terminal servers that implemented "rlogin". Don't, repeat DON'T, put them in your hosts.equiv files unless you're sure about them! Even worse, don't EVER put "+" in a hosts.equiv file (assuming YP support). This particular slipup on the Annex is fixed in Annex R4.1. The Annex will assure the validity of the rlogin protocol messages. Even better, if you use Annex security to authorize users, the Annex *will* fill in the rlogin protocol message correctly, meaning that you won't be "needlessly" prompted for a host password if that host has you in its hosts.equiv file. > Also, it's > possible, but really painful to get someone else's UUCP to dialup through an > annex. I gave up, as it was much easier to just leave one modem directly > connected to a host, and only tell people we uucp with what that phone > number is. This is something that can be gotten around in a few ways, such as using rtelnet, or "dedicated ports". A "modern" UUCP also makes such chat scripts easy. -- John Robert LoVerso Xylogics, Inc. 617/272-8140 loverso@Xylogics.COM Annex Terminal Server Development Group {encore,sequent}!xylogics!loverso [formerly of Encore Computer Corp]