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Path: sserve!newshost.anu.edu.au!munnari.oz.au!sgiblab!darwin.sura.net!howland.reston.ans.net!xlink.net!zib-berlin.de!netmbx.de!Germany.EU.net!EU.net!sun4nl!tuegate.tue.nl!news.win.tue.nl!wzv.win.tue.nl!gvr.win.tue.nl!guido From: guido@gvr.win.tue.nl (Guido van Rooij) Newsgroups: comp.os.386bsd.bugs Subject: Re: PROBLEMS WITH FreeBSD Date: 1 Jan 1994 19:29:03 GMT Organization: Eindhoven University of Technology, The Netherlands Lines: 38 Message-ID: <2g4itv$fbu@wzv.win.tue.nl> References: <CIq8w7.7rM@csi.compuserve.com> <2g0kdl$2d9@cleese.apana.org.au> <2g2ere$esn@solaria.mil.wi.us> NNTP-Posting-Host: gvr.win.tue.nl jgreco@solaria.sol.net (Joe Greco) writes: >Now wait a minute. I thought the SIO drivers were supposed to provide >bidirectional capability. How is this supposed to work? I've been looking >for documentation for about a week, and have yet to find anything. Only when you make them bidirectional. Use comcontrol <device> bidir to tuen on or ,, ,, -bidir to turn of. >Under SunOS, which IMHO has a "reasonable" bidirectional mechanism, open() >will block on the opening of a terminal device unless there is carrier AND >the port is not already open in the other direction (cua0 or whatever). >cua0 can be opened regardless of the state of carrier, unless the port is >already open in the other direction (tty00 or whatever). This allows getty >to hang on tty00, and uucp/kermit/tip/cu to call out on cua0, transparently. This indeed is the way sio works in bidir mode. But you dont want bidir capabilities for a hard wired terminal...do you? And then when you have a hard wired terminal, you have to make sure that the wiring is correct. >Ideally, I'd _love_ to see this done with SIO, and I was actually under the >impression that SIO had a direct analogy of some sort. Indeed it has so. And I agree that there should be documentation on this. >Setting clocal or locking DCD in some manner could make all of this rather >difficult, if it works at all like any other implementation I've seen. So >what's the deal? Does SIO provide bidirectional capabilities? And if so, >what is the technique used to implement (and/or use) it? You would only set clocal for hardwired terminals. In the bidirectional case, clocal would result in the getty not blocking on open. >... Joe -Guido -- Guido van Rooij | Internet: guido@gvr.win.tue.nl Bisschopsmolen 16 | Phone: ++31.40.461433 5612 DS Eindhoven | ((12+144+20)+3*sqrt(4))/7 The Netherlands | +(5*11)=9^2+0