Yeah, thanks all.
I had thought of remote desktop after I went to bed.
I looked up what I had been doing back then. It was Lantastic-Z, and I used the other computer(s) as print servers, file servers, etc.
Remember, this was back well before gHz machines and (relatively) stable versions of Windows - we were running pretty much everything under DOS.
What exactly are you looking to don this other computer. It's not like most people need any kind of machine to sit idly by and just crunch data. Unless you're doing a lot of high res video work and are looking for a rendering farm, it seems like it's not something you would really need.
I'm probably not like other people. I put the particular computer in question together for about 20 bucks using stuff I had laying around. It doesn't have to do anything other than sit on the line and get files occasionally, and then distribute them to the mirror array. I wrote all the software to do that years ago and just updated it to work under FAT32 (NTFS is hopeless for that stuff). I don't mind having a computer do nothing for 99% of the time. I just want to tie some of them together and stick things here and there without having to get up and go there.
I will check out the other suggestions, too.