wtm@uhura.neoucom.EDU (Bill Mayhew) (07/01/90)
Ah, the old mysterious reappearing getty trick, chief. By th way, OBM == On Board Modem, for the Unix PC, for those you you were reading this and wondered what the heck we were talking about. The 3.51 O/S software is rigged with the assumption that if you want to use the OBM at all, then you want the OBM to both make and receive calls. Not a terribly good assumption, if you ask me. For instance, I use a Trailblazer external modem ot handle all the uucp traffic for my mahcine on a dedicated data phone line. The OBM is a pretty lousy modem by today's standards. I have a $100 Radio Shark modem that seems to have an adaptive equalizer that handles poor connections where to OBM is unable to maintain a reliable connection. Now, I would like to keep the OBM around for emergnecy dail-out use for on my voice line at times when the data line is busy. I don't want the OBM to automatically answer; I'd rather have Voice Power or myself handle human calls. Much of the software that uses OBM calls the programs /usr/bin/geton.sh and /usr/bin/getoff.sh. As you might guess, the first is a shell program that calls /usr/bin/setgetty to enable a getty, while the latter diables the getty. Setgetty edits the /etc/inittab file (A real no-no in my book!) and and calls init to mark re-read the inittab. My quickie fix was to patch geton.sh to that it did not really call setgetty. Geton.sh has to appear to work, or software such as cu and uucico will fail. Some bogosities, such as /etc/ph seem to man handle inittab on their own, so there isn't much you can do to stop getty being reenabled unless you want to patch bianries. One thing you can do is to run /usr/bin/setgetty ph1 0 from your crontab on a regular basis to assue that any offending getties that slip through your wall of defense get squished out. Of course, you should use ph0 in place of ph1 if the example above, depending upon your configuration. The Usenet collective wisdom is that line 0 should be voice, if possible, and line 1 should be data only, if possible. I don't recall the origin of the folklore now, but it has been around several times. Perhaps the most pragmatic solution is to get a ring defeating netowrk from a telephone supply vendor. I imagine that such a network has a varistor and a couple of diodes so that the downstream device doesn't get sufficient ring voltage to trigger, yet can still complete the loop when going off hook. Heaven only knows; an AT&T phone Center might even have one!?... As far as surviving a call-wainting tone blitz, the solution is central-office dependent. In some areas, dialing *70 and *71 can be used to control call waiting. It happens that where I live, it is impossible to defeat call waiting. Even if you program your own modem to have a sufficeintly long loss-of-carrier delay, the other side will have problems, because of the blanking while call waiting tones are presented to your side of the connection. The only real effective solution is to have a dedicated data line. I'm glad that I have two lines, and feel that it is well worth the extra $20 US per month that it costs. ==Bill== -- Bill Mayhew Northeastern Ohio Universities College of Medicine Rootstown, OH 44272-9995 USA phone: 216-325-2511 wtm@uhura.neoucom.edu ....!uunet!aablue!neoucom!wtm
car@trux.UUCP (Chris Rende) (07/03/90)
In article <1990Jul01.113820.18646@uhura.neoucom.EDU>, wtm@uhura.neoucom.EDU (Bill Mayhew) writes: > Much of the software that uses OBM calls the programs > /usr/bin/geton.sh and /usr/bin/getoff.sh. As you might guess, the > first is a shell program that calls /usr/bin/setgetty to enable a > getty, while the latter diables the getty. Setgetty edits the > /etc/inittab file (A real no-no in my book!) and and calls init to > mark re-read the inittab. [set new_to_3b1 on] I found that phtoggle, geton.sh, etc... where only changing the first character of the /etc/inittab line that contains ph0 from a ' ' to a ':' or back again. (In addition to creating/removing /usr/spool/uucp/LCK..ph0). Unfortunately, this only had a temporary effect - after a UUCP conversation I found the /etc/inittab back the way it was and a getty on the line again. What finally worked was changing the 'respawn' to 'off' in the /etc/inittab (like a normal Unix). I still have to do phtoggle's in order to control /usr/spool/uucp/LCK..ph0 - but at least there is no getty - which keeps the OBM from answering the phone. Does the OBM understand Hayes commands? The Hayes command "ATS0=0" would tell a Hayes compatible modem not to ever answer the phone. > As far as surviving a call-wainting tone blitz, the solution is > central-office dependent. In some areas, dialing *70 and *71 can > be used to control call waiting. My call-waiting disable sequence also has a '*' in it. However, will the '*' be properly recognized by the routines which generate the dialing tones? I.e,: will '*70,15551212' as a dialing sequence work? (This is a valid Hayes compatible sequence). car. -- Christopher A. Rende Central Cartage (Nixdorf/Pyramid/SysVR2/BSD4.3) uunet!edsews!rphroy!trux!car Multics,DTSS,Unix,Shortwave,Scanners,StarTrek trux!car@uunet.uu.net Minix 1.2,PC/XT,Mac+,TRS-80 Model I,1802 ELF "I don't ever remember forgetting anything." - Chris Rende
rlw@ttardis.UUCP (Ron Wilson) (07/04/90)
In article <482@trux.UUCP>, car@trux.UUCP (Chris Rende) writes: >In article <1990Jul01.113820.18646@uhura.neoucom.EDU>, wtm@uhura.neoucom.EDU (Bill Mayhew) writes: >> Much of the software that uses OBM calls the programs >> /usr/bin/geton.sh and /usr/bin/getoff.sh. As you might guess, the >> first is a shell program that calls /usr/bin/setgetty to enable a >> getty, while the latter diables the getty. Setgetty edits the >> /etc/inittab file (A real no-no in my book!) and and calls init to >> mark re-read the inittab. > >[set new_to_3b1 on] > >I found that phtoggle, geton.sh, etc... where only changing the first >character of the /etc/inittab line that contains ph0 from a ' ' to a ':' >or back again. (In addition to creating/removing /usr/spool/uucp/LCK..ph0). > >Unfortunately, this only had a temporary effect - after a UUCP conversation >I found the /etc/inittab back the way it was and a getty on the line again. I have never had this occure on my stock Unix 3.51 - once the setgetty h1 O is done, the getty stays off - maybe you should only use setgetty >Does the OBM understand Hayes commands? The Hayes command "ATS0=0" would >tell a Hayes compatible modem not to ever answer the phone. No. All modem control is via ioctl calls. >> As far as surviving a call-wainting tone blitz, the solution is >> central-office dependent. In some areas, dialing *70 and *71 can >> be used to control call waiting. > >My call-waiting disable sequence also has a '*' in it. However, will the >'*' be properly recognized by the routines which generate the dialing tones? >I.e,: will '*70,15551212' as a dialing sequence work? (This is a valid >Hayes compatible sequence). There should not be a roblem here. >Christopher A. Rende Central Cartage (Nixdorf/Pyramid/SysVR2/BSD4.3) - Ron ---------------------------------------------------------------------------- "We were wondering when somebody would discover that one." - The response of a customer support rep to a customer's phoned in bug report (name of company with held to protect the guilty). iwblsys\ rlw@ttardis uunet!rel.mi.org!cfctech!ttardis!rlw sharkey.cc.umich.edu/