Q] Can I use a splitter on CAT 5 patch cable to connect two computers to one data source?
[A] No. The problem with this has to do with the fact that a computer has to communicate with the network using a unique address. When using a DSL or Cable router for example, these addresses are given out by the router to each PC, giving it a unique identity on the network. If you attempted to join two different computers on the single connection on a DSL or Cable modem, using just an RJ45 splitter, it would not work due to the fact that both computers would be trying to commmunicate at the same time to the same place.
Is this how it is hooked up?