Well, i would like to say 2 things:
1. a Dial Up adapter is a modem that can identify dial tone and Dial Up: it can send the correct Dual Tone Multi-Frequency codes ... An example of non-dial up modems is the one in which you plugin 2Mpbs connection, but not all those are non dialup either.
2. I have two PCS, on on dual boot running XP and 98, and one running 98. When they both run in 98 they see each other. When the first runs in XP mode, it does Not see the 98. By "see" i mean see it on the local connection, however i can still "use" the connection (over the cross over cable) and play for example Red Alert 2.
To test if your card is running, type:
ping 127.0.0.0
at the command prompt, this address is your local pc.
To see if the cable is working, ping the pc as per the address you gave it when you installed the TCP-IP stack for that connection, for ex:
ping 192.168.0.1
Finally, instead of Internet Connection Sharing, you can use Wingate between 2 98 PCs: when one of the is connected to the internet, the second one can also send packets to the internet if you specify the PC with the modem as your primary domain name server.