pp. 130, 173

1. On page 130, Arnold assures the group that the computer system is secure: "The system does not communicate with the outside, so it cannot be influenced by modem.

2. Then, on page 173 Nedry yells at Arnold to put the phone down, that he'll screw up the data stream. He says, "I've taken all the lines that communicate outside."

Sure sounds like a modem in action to me. In any case, if Nedry was using the modem as an excuse for the jammed phone lines, Arnold should have picked up on it. After all, he's the one that explained the fact that there weren't any to the group!!