First, make sure you have a kernel built that will recognize you PCMCIA modem. Check to see that it works. Normally the modem will com up at tty02 (and tty03 if you have two modems). Modify your /etc/ttys file to enable the tty line, for example:

tty02   com Generic336 out

Add the following entries to your /etc/pccard.conf file:

com     @insert "/etc/netscripts/modem.up tty0%U"
com     @remove "/etc/netscripts/modem.down tty0%U"

The files /etc/netscripts/modem.up and /etc/netscripts/modem.down can actually be links to the same script, which is:

#!/bin/sh
sleep 1
gettystat -r $1

Now, when you insert or remove your modem, gettyd will take notice.