The rs-232 port is used for down loading software to your system. This port allows you to down load upgraded software from your computer to your pre-amp via a null modem cable. I have pulled software right off the internet and down loaded to my pre-amp using this port. It's pretty neat. I don't think I'd worry about pre wiring in walls but if you do make sure you use the right cable with your particular pre-amp.
RS 232
I am going to buy a home theater soon centered around a HD rear projection TV. I am in the process of putting in the wires. We are remodeling a house. I will be buying a high quality amp and sound processor?pre-amp. I am looking at what type of wires to put in before we sheet rock. I have put in the speaker wires. I am looking at what to run from the equipment rack to the TV which will be 10 feet away. What is a RS 232 cable/connection used for. Can anyone give me some input on cables. Thanks,