ok im going to give you all that i know.
i have a sanyo tube tv with what i believe are called RCA ports.
i have duel monitors already that run off individual ports.
i have a DVI-I to 3 RCA Component RGB Cable and im not sure how to hoock this up so that i can use it as a monitor.
Eh if its a tube TV that RCA socket is going to be analog, not digital. (i.e. you can do it by svideo, but the quality will be poor). Digital RCA connections are called component and they're generally RGB coloured sockets on the TV, if the socket on the TV is Yellow, its definitely analogue video RCA, and it's generally coupled with a Red and a White which is audio.