CompuServe Messages

>>either PAULA or the driver chip<< If somebody has a dead serial port, it is most likely the driver chips(s). The UART itself is inside of Paula(along with other things). The good news is the driver chips can be had at radio shack for a couple of dollars, bad news is you need to unsolder the old one(s). Here is how to tell, connect a modem to the port, start terminal program. now watch the lights on the modem for response as you type on the keyboard. I type 'ATZ' and see what it does. If it does nothing, have someone call the line and see if you see 'ring' on the screen. There are 2 chips, Quad line driver, and Quad line receiver. You should be able to figure it out from here…. I have made this repair in the past, put in sockets in case it happens again. I don't believe the CIA chips are involved with the serial port at all, but I would have to double check the prints. From my experience, the receiver chip seems to be the one to go. Hope this helps. -Peter