I read your post 2 times and can't find the make and model of what we are dealing with. Serial ports appear on the rear of some motherboards. Some are just headers on this or another board. But given the details so far all I can offer is that you tell more or just open it up.
Hi, I'm playing with a reconstructed computer with the intention of using it for Ham Radio appliations.
I have installed XP pro and broadband and, so far, all is well. I am using it right now !
However, the computer only has a games port (15 pin) and LTP printer port.
According to the system analysis, it has a coms port - on the usual address.
Q Where is this comps port physically fitted ? I haven't taken the side cover off yet - but surely it's not just on the motherboard !