It sounds like you just need to find out which wire pairs are which and whether or not they are normally open or normally closed. Is there a connector visible to plug in the alarm control box? Is a siren prewired? Do you want the alarm to call the police? What kind of power is provided? Does it have battery backup? Other things to consider.
Well I'm not at the apartment yet, but will be soon. I'm not even sure what kind of alarm I could hook up to this if its possible. I've searched Google but havent found anything on this. I'm sure ADT and the others dont want people to know its possible.