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The pins on the comm ports are hardwired to a communications chip and you do not have any choice on what functionality is available on each pin. It is possible to play games in assembly that will cause certain things to happen on pins other than either 2 or 3 (I don't remember which is the output), but it would be pretty pointless. The chip is designed to have input on 2 and output on 3 (or the reverse, if I have it backwards) and you just don't have any choice about it.
I don't know who told you you could do what you want with a comm port, but they were mis-informed.
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THanks.
I came to that answer a while ago. I am actualy using voltage free contacts, so using the other pins is no problem. All I do is look for the other comm events other than the receive event.
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You can configure the parallel port this way. Only the difference is that you can send either 1 byte parallel, or 8 bytes serial and then decode with software. I'm pretty sure that you can send a nibble and recieve a nibble at the same time with a parrallel port, but I'm not sure. I read that somewhere in a document on the 82C55(pport chip). I know that you can surely send and receive data using 2 Parallel ports... Infact, there are networking programs that use 2 pports for this. At school, one project in someone's tech class was to make a joystick with the parallel port.
What exactly are you trying to do?
