Well, I've watched the lights on the modem (it's not a dumb modem, btw...I remember those days...this is a Practical Peripherals 56K minitower, and responds to most of the query commands when "test modem" is run, either on Windows or Linux), DCD is labeled CD only, and I can see that come high when the connection is made. Initially both TX and RX flicker as the handshake takes place. I'm convinced that line is working properly and that there is no problem with the cable. I've used both the cable I originally had with the PP modem as well as a new cable that came with a modem I bought recently, a Made-in-China version of a Hayes, this one called a Hayes Accura V.92 Data/Fax modem. I get identical results with both cables and with both modems, which is to say, they both work fine with Windows 2000 Pro, they neither will receive with Slackware. Therefore, I doubt seriously the fault is in the hardware.

Yesterday, for an experiment, I changed the IRQ for ttyS0 to 5, and nothing worked. Further, I obtained the phone number of Yahoo's dialup specialists and will be talking to them as soon as I am prepared to be that patient.

This indicates that the modem has an active connection on the telephone line.

However, when that connection is made, the modem raises DCD on the cable to the serial port of your computer. If your cables do not have the DCD line, then your serial port will not see this signal, so no data will be received.

This link shows the correct wiring for a DTE-DCE cable
http://circuits.epanorama.net/docume...232cables.html

On a hunch, when I saw an ad on this forum for dialup for $4.95/mo, I decided to try it to prove or disprove my ORIGINAL THEORY about the problem, which was my ISP (AT&T via Yahoo) was blocking Linux access.

This post is to prove my original theory since I am now logged on using the exact same hardware as before, the exact same settings as before, and the only difference being the god damned ISP.

I have to admit further I have changed distros to PCLinuxOS and therefore this is an Adios. I hope this thread will be of use to any other dinosaurs like myself using dialup who encounter a similar problem will find some solutions.

Further research yielded this fine article:
http://www.theory.physics.ubc.ca/ppp-linux.html

There is a good possibility the problem resides right within what is discussed in this essay, namely that AT&T is not expressly disallowing dialup access by anyone other than Windows apps, however, that's essentially what is happening assuming they are using Microsoft's CHAP stuff.