dan@lclark.UUCP (Dan Revel) (03/23/89)
I've been going around and around trying to get these things to work right and it just seems like a catch 22 situation. Perhaps someone can shed some light on this for me. What I'm trying to do is to connect some 1200/2400 baud modems to our VAX 750 (4.3bsd unix) to use as dial-in ports. (The modems are 'Hayes compatible' Practical Peripherals...) I have the modems defaulting to 2400 baud and answering on the first ring. With the standard getty (D2400) they had trouble setting the right speed for 1200 baud calls (they did OK if you sent a break, but sometimes you just can't send a break, Red Ryder fer instance...). OK, I thought, I can change getty to read the connect message from the modem and set the line-speed accordingly. Well, it's not that easy because the modems don't assert a carrier detect until *after* they send their CONNECT message (always at a known speed, 2400). OK, the modems can be set to hold CD on, or else the dmfs driver has bits in dmfsoftCAR which can be set, great, it works! But now I need to get processes to hang-up when the madem goes off-line, and with CD dummied up they don't seem to notice when that happens. I would like to twiddle the dmfsoftCAR bits but can't get at them until I open the device, I can't open the device unless the CD is on... around and around. Any helpful hints and/or suggestions? Many thanks, Dan -- dan@lclark tektronix!reed!lclark!dan Dylsexics untie! (-|
dem@uwslh.UUCP (David E. Miran) (03/30/89)
In <400@lclark.UUCP> dan@lclark writes > > What I'm trying to do is to connect some 1200/2400 baud modems to our > VAX 750 (4.3bsd unix) to use as dial-in ports. (The modems are > 'Hayes compatible' Practical Peripherals...) followed by a description of the problems involved in trying to handle multispeed modems, especially with PC terminal emulators that cannot send a break. There is a very satisfactory solution to this possible (if you are willing to buy better modems). Get some Multitech MT224EH modems (or better yet MT696EH). These are multispeed modems which run at 2400 baud (9600 for the MT696EH). These modems have the very useful feature that their phone line speed does NOT have to match the speed to the computer. They can answer the phone at speeds of 300, 1200, 2400, 4800 ( with MNP 5 compression) (also 9600 and 19,200 for the MT696EH) while always talking to the computer at a fixed speed (like 9600). The modem then uses xon/xoff to do flow control. We have some of the MT224EH modems and really like them. We are planning to get some MT696EH modems in the near furture. We can buy them for $323 for the MT224EH and $395 for the MT696EH. Of course, this is a state contract price but you should be able to get close to these prices. These modems are the ideal solution to the speed recognition problem for us. Hope this helps. -- David E. Miran ...!{rutgers,ucbvax,harvard}!uwvax!uwslh!dem Wisconsin State Hygiene Lab or dem%uwslh.uucp@cs.wisc.edu University of Wisconsin (608) 262-0019 465 Henry Mall Madison, WI 53706
bill@bilver.UUCP (bill vermillion) (04/01/89)
In article <420@uwslh.UUCP} dem@uwslh.UUCP (David E. Miran) writes: }In <400@lclark.UUCP> dan@lclark writes }> }> What I'm trying to do is to connect some 1200/2400 baud modems to our }> VAX 750 (4.3bsd unix) to use as dial-in ports. (The modems are }> 'Hayes compatible' Practical Peripherals...) }There is a very satisfactory solution to this possible (if you are willing }to buy better modems). }Get some Multitech MT224EH modems (or better yet MT696EH). ... }... They can answer the phone }at speeds of 300, 1200, 2400, 4800 ( with MNP 5 compression) (also 9600 }and 19,200 for the MT696EH) while always talking to the computer at a fixed }speed (like 9600). The modem then uses xon/xoff to do flow control. ^^^^^^^^^^^ Which will break uucp transfer. Can this modem be set not to use flow control and just have the system protocols take over? -- Bill Vermillion - UUCP: {uiucuxc,hoptoad,petsd}!peora!rtmvax!bilver!bill : bill@bilver.UUCP