zhou@brazil.psych.purdue.edu (Albert Zhou) (11/11/90)
Since my phone is always busy with modem, I ordered a call waiting recently. However, it doesn't work well. Two problems: (1) The computer does not generate a beep as the telephone does when there is another call coming. Instead, the screen outputs some strange characters which can sometimes be ignored, especially when you are not really attending it. Nevertheless, this is easily solved by writing a simple clock-interruption program to capture those characters and generate some beeps. (2) The second problem is harder. You cannot switch to another calling without hanging up the modem first. I think it is probably because I donot fully understand the mechanism of call waiting. Solutions to the questions (especially to the second one) are appreciated!
tnixon@hayes.uucp (Toby Nixon) (11/12/90)
In article <11464@j.cc.purdue.edu>, zhou@brazil.psych.purdue.edu (Albert Zhou) writes: > Since my phone is always busy with modem, I ordered a call waiting recently. > However, it doesn't work well. Two problems: > (1) The computer does not generate a beep as the telephone does > when there is another call coming. Instead, the screen outputs some strange > characters which can sometimes be ignored, especially when you are not > really attending it. Nevertheless, this is easily solved by writing a > simple clock-interruption program to capture those characters and generate > some beeps. Except for a very few modems (like the Hayes Personal Modem 1200 and 2400) which have been specifically designed to handle Call Waiting, most modems consider the call waiting beep to simply be "line noise". At best, on an error control modem, your data simply is delayed for a moment; at worst, if the interruption is long enough, you get disconnected. Usually, you at least see a burst of garbage characters, if you're not using error control. > (2) The second problem is harder. You cannot switch to another > calling without hanging up the modem first. I think it is probably because > I donot fully understand the mechanism of call waiting. That's exactly right. Without cooperation from the communications software, there's no way to suspend a modem call and switch to another call on the same line. Modems transmit continuously, and if you take one of them off the line the other one will drop the call. The only way around this is to have a lot of cooperation between the comm software at each end, so that they can send messages saying "I'm going to drop carrier for a moment; please tell your modem to not go on-hook when I do, and reconnect when I come back." Prodigy tries to do this, but almost no other network or BBS software has the capability. In general, call waiting and modems are considered to be incompatible. If you use your modem a LOT, the solution is to get a second phone line, not call waiting. -- Toby -- Toby Nixon, Principal Engineer | Voice +1-404-449-8791 Telex 151243420 Hayes Microcomputer Products Inc. | Fax +1-404-447-0178 CIS 70271,404 P.O. Box 105203 | UUCP uunet!hayes!tnixon AT&T !tnixon Atlanta, Georgia 30348 USA | Internet hayes!tnixon@uunet.uu.net
dave@westmark.WESTMARK.COM (Dave Levenson) (11/17/90)
In article <11464@j.cc.purdue.edu>, zhou@brazil.psych.purdue.edu (Albert Zhou) writes: > Since my phone is always busy with modem, I ordered a call waiting recently. > However, it doesn't work well. Two problems: ... (2) The second problem is harder. You cannot switch to another > calling without hanging up the modem first. I think it is probably because > I donot fully understand the mechanism of call waiting. Call waiting is not a very good solution to sharing a phone line between a modem and a person. Call-waiting does not let you carry on two conversations at once. At best, the computer and its associated modem can drop the data call in progress, allowing the person to take the second incoming call. For most applications, being cut off in the middle of a transaction is hardly a robust way of accomplishing anything. I suggest that you look at the difference in cost between call waiting and an additional line. The second line on the same account usually costs several dollars per month less than the first line. Two lines probably only cost about $2.00/month more than one line with call-waiting service. With two lines, your computer can keep on talking when your voice call arrives. If your lines are being used for different purposes, don't get hunting or other options. -- Dave Levenson Internet: dave@westmark.com Westmark, Inc. UUCP: {uunet | rutgers | att}!westmark!dave Warren, NJ, USA AT&T Mail: !westmark!dave [The Man in the Mooney] Voice: 908 647 0900 Fax: 908 647 6857
rts@polari.UUCP (Randy Seacat) (11/19/90)
Also, remember that you disable call waiting by dial *70 with tone, or 1170 pulse in most areas. This way, if you are doing some important with the modem, you wont get dumped. Have callwaiting on a data line can be a real pain, but you do have option of turning it off. If the above does not work, call your operator and ask what the command in your area is.