Televideo 912C and General DataComm Gen Net Terminal Server

I have a Televideo 912C and a General DataComm Gen Net Terminal Server. I want to make these two machines talk to each other. I think it would be really cool to be able to display a Trek game or something. But I have a couple of problems. First of all, I'm mostly a PC guy. I don't know anything about these machines. Secondly, I don't even think the ports on the back of the Gen Net are RS-232C. If they are, there's a protocol problem or something, because what gets echoed back isn't what I type. (I type several characters before one is echoed, and the echoed character is usually an odd-looking non-character.) I don't know the password on the server, and I don't know how to operate its control keyboard. Here's something else weird--you have to actually remove the front cover to turn it on and off! Here are some pictures of these machines http://mywebpages.comcast net/fastluck1/Televideo.htm. Check out the terminal--it looks really cool. Can anyone give me information on operating these machines, or point me in the right direction? Thanks in advance, John