Thanks, I figured that there should be no alarms using the no handshake null modem (4 and 5 jumped and 6,8,20 jumped). That's why I figure my connection on the main board is fried. I have also checked the machine for other ports but did not find any. The maintenance manual shows that there is an option 1 card (A16B-1210-0350) that usually comes with the machine that also has the RS232 connecter. I think this is the board usually connected to the tape reader but my machine did not come with that feature. I just hope installing it won't require too many parameter changes!