make a text <marquee> on a LED screen?

i have to do a project regarding LED screens.. i have thought of this .. i am going to feed text from computer and it should be displayed on a LED screen . the text should be scrolling(just like we see it on the big stock exchange buildings) the twist:- i have 3 computers from which i will be giving different char and numero inputs , all these must be displayed on the same LED screen.. ex:- michelle2213pally3321spetthi1922......so on i dont know where do i start from.. what should be the font size? its just a project so a small led screen should do(enough to display 8chars at once)