Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!pasteur!ucbvax!tut.cis.ohio-state.edu!cs.utexas.edu!milano!bigtex!texbell!ssbn!bill From: bill@ssbn.WLK.COM (Bill Kennedy) Newsgroups: comp.dcom.modems Subject: Re: About "+++" in-band escapes Summary: Change the escape character Message-ID: <1146@ssbn.WLK.COM> Date: 26 Feb 89 15:22:06 GMT References: <20335@lll-winken.LLNL.GOV> <20736@lll-winken.LLNL.GOV> <3695@phri.UUCP> <17584@onfcanim.UUCP> Reply-To: bill@ssbn.WLK.COM (Bill Kennedy) Distribution: na Organization: W.L. Kennedy Jr. and Associates, Pipe Creek, TX Lines: 47 In article <17584@onfcanim.UUCP> dave@onfcanim.UUCP (Dave Martindale) writes: >In article <3695@phri.UUCP> roy@phri.UUCP (Roy Smith) writes: >> >> Various people have been grousing about the "+++" in-band escape [ ... ] > >The place where it *is* a real pain is with a modem connected to >a UNIX machine as a dialin line. [ scenario about remote user wanting local modem's attention ] >So, you really need some way of turning off the in-band escape >sequence for a modem used as an answer modem. Yet, if the same modem >is also used for dialout, you can't disable command mode entirely. There's another reason to change the personality but it's easily done. Most of ssbn's modem events are uucp transfers and the Trailblazers here work best with all handshaking defeated. The occaisional dial up user < PEP speeds, however, needs XON/XOFF handshaking because the interface speed is locked at 19,200bps and a big cat or ls can easily over run the TB's buffer. This gets set up in /etc/profile as the user is getting logged in. If they say they need flow control, get the modem's attention, enable XON/XOFF, and proceed. It gets disabled by the DTR transition/reset at disconnect. What Dave points out is correct. If you use +++ you're very likely to get the attention of both modems. That happened to me when I was testing /etc/profile. For a modem with NVRAM that will reset on a DTR transition, this is no problem, just change the attention character. My Hayes, USR, and Telebit book says that's S2. I changed mine from 43 (+) to 126 (~) and saved it with &W. The USR doesn't have NVRAM, but you could achieve the same result by issuing the S register change prior to actually spawning the uu/getty. SCO has a dial program that allows you to fondle the modem before and after an outbound call, or a dirt simple uu/getty program to issue the command and exec to the real uu/getty should be easy enough. You only need to do that if your modem can't save the current register set. The sword has two blades if you are as thoughtless as I am. You have to remember what the new attention character is if you need to talk to the modem. Further, if everyone in the world changes to the same attention character, you're right back where we started with +++ :-) To save myself from me, I change S2=43 in the dial script so that I can mindlessly pound on + in cu and not run afoul of neighbors' modems that have done what I did with ~ for answer calls. -- Bill Kennedy usenet {killer,att,cs.utexas.edu,sun!daver}!ssbn!bill internet bill@ssbn.WLK.COM or attmail!ssbn!bill