chris@mimsy.UUCP (Chris Torek) (01/29/88)
In article <178@jim.odr.oz> brw@jim.odr.oz (Brian Wallis) writes: >The kernel support needs to be able to reset the modem to a useable state as >well, since the dialout program may have put it into an unuseable state. Say >set the modem to not answer any incoming calls, or to answer them all at 300 >baud! Any decent modem will be able to reset to EEPROM or switch settings on DTR drop. (This makes the Hayes 2400 indecent, since doing this requires giving up something else, as I understand it.) 4.3BSD's UUCP is careful to reset the modem after it is done with it, Just In Case. -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163) Domain: chris@mimsy.umd.edu Path: uunet!mimsy!chris
dave@onfcanim.UUCP (Dave Martindale) (02/18/88)
In article <10379@mimsy.UUCP> chris@mimsy.UUCP (Chris Torek) writes: >Any decent modem will be able to reset to EEPROM or switch settings >on DTR drop. (This makes the Hayes 2400 indecent, since doing this >requires giving up something else, as I understand it.) Indeed. You can configure the modem so that when DTR drops it 1) hangs up the phone and will not answer incoming calls, or 2) resets the modem to the settings in EEPROM. Unfortunately, you want BOTH of these, and Hayes forces you to choose just one (or none) of them.
sl@van-bc.UUCP (Stuart Lynne) (02/19/88)
In article <15551@onfcanim.UUCP> dave@onfcanim.UUCP (Dave Martindale) writes: >In article <10379@mimsy.UUCP> chris@mimsy.UUCP (Chris Torek) writes: >>Any decent modem will be able to reset to EEPROM or switch settings >>on DTR drop. (This makes the Hayes 2400 indecent, since doing this >>requires giving up something else, as I understand it.) > >Indeed. You can configure the modem so that when DTR drops it >1) hangs up the phone and will not answer incoming calls, or >2) resets the modem to the settings in EEPROM. > >Unfortunately, you want BOTH of these, and Hayes forces you to choose >just one (or none) of them. There is a work-around for this problem. Set ats0=0&w. This tells the modem to never answer the modem. Then whenever you reset DTR you have a modem which won't answer the phone anymore. Now arrange to have your getty replacement (what you're still running factory standard!!) to send ats0=1 to prime the modem to answer the phone. This can be done for example with: #! /bin/sh # getty replacement echo ats0=1 exec /etc/getty $* Alternatively have your getty replacement actually monitor the line for "RING" and *then* explicitly send ata. Various programs have been posted to the net over the last couple of years which will do this for you. I'd post mine but it's to hacked up to be of any use to anyone not running on a Callan. It's an offshoot of the program called modem. -- {ihnp4!alberta!ubc-vision,uunet}!van-bc!Stuart.Lynne Vancouver,BC,604-937-7532
dave@onfcanim.UUCP (Dave Martindale) (03/07/88)
In article <1678@van-bc.UUCP> sl@van-bc.UUCP (Stuart Lynne) writes: >There is a work-around for this problem. > >Set ats0=0&w. This tells the modem to never answer the modem. Then whenever >you reset DTR you have a modem which won't answer the phone anymore. > >Now arrange to have your getty replacement (what you're still running factory >standard!!) to send ats0=1 to prime the modem to answer the phone. This can >be done for example with: But normally getty's open hangs until carrier detect comes up. In order to send commands to the modem before that, you need to configure the line or build the cable so that carrier detect is ignored - not a good idea, since a user hanging up will not generate a hangup signal. Or, if you have an alternate device that allows open without waiting for carrier, you can use that - but this requires kernel mods. My eventual solution was simple - we bought a Telebit Trailblazer, and it is now our principal uucp modem - it works fine for both dialin and dialout. The backup modem is an older Vadic VA2400, which also works fine for both dialin and dialout without handholding. All of the Hayes modems have now been relegated to dialin-only use.