Thanks to all the posts. I did mention previously:
"A few things have happened since then and recently. RS232 ports on computers have become rarer and rarer, RS232 to USB converters are very hit and miss (at least with what we are using currently) with almost all of them being "miss", and most importantly, the box is failing and the company that built it is out of business."
However, it's a long thread here 
and i appreciate people thinking of suggestions outside of the box (pun intended). I know the box is working intermittently (which is not good), and i will see if i can get it to give some output on my old XP computer, but there is also an issue of expanding and being able to build additional boxes. therefore, the RS232 to USB converter, while cheap and quick, is not the answer here. My friend was able to find one (after many failures) that worked:
What I've been told is that one of the issues with these types of cables is that the drivers are not updated for Windows 7 and especially Windows 8, or that Windows 7 or 8 doesn't recognize a lot of them. As time passes and newer Windows come out, this I believe is going to happen even more for the few that work with current Windows. Nevertheless, the thought of building additional units down the road is important here, as well as the challenge.:-).
In response to the post from mschramm, that would be cool if it is that simple. I think once i get my hands on the RS232 shield and play around with it for (probably) a long while, hopefully i'll find out.
thanks again to all those helping here. I appreciate the suggestions. Sorry if new info comes out from me as i'm posting about this process - i don't always know what to post until someone asks.