Q: How do you set up the USR Sportster X2 modems to work with RH 5.0? They are listed as unsupported/incompatible. I have one on my system and am having no luck getting it operational.

A: Most modem problems I've found are a matter of trying to use the wrong COM port. Many will by default be configured (in the BIOS) as COM port 2 (/dev/ttyS1). If it's a modem you have put in yourself, it's generally COM 3 (/dev/ttyS2). I`m assuming you have an internal modem. If you have an external modem, much of the above still applies, but you will be using ttyS0-1 (in general).

In general, /dev/modem should be a link to /dev/ttyS(0-4). We configure this, but it could be you've changed your BIOS, it got cleared somehow, or something of the sort. Many programs require this link to function. You can test your com ports by using minicom or cu. Minicom is fairly straightforward. cu is quicker and dirtier.

Try this to test com ports:

cu -38400 -lttyS(0-4)

(Note: If you can't see what you're typing on-screen, you are talking to the wrong serial port.)

(This should return your modem type amoung other things.)

atd (some number)
(You should hear dialing.)

~. (exits cu)

Note: Sometimes, in your attempts to use your modem, you've left a lock file behind. The easiest way to clear up any such problems is to run minicom and exit. (control-a x)