external serial modem

You might also check to be sure the phone line is plugged into the LINE
jack and the phone into PHONE jack on the modem. Also check the polarity
of the phone line. If you don't have one, get a phone-line tester for $5
at Radio Shack; if it lights RED instead of GREEN, switch the wires inside
the phone jack.

Crazy as that sounds, some modems won't work with the line plugged into
the wrong jack, or with a mis-wired phone line.

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