In order to make a crossover cable, for your computer, from scratch, you will need the following: Ethernet cable, an RJ45 connector, and a crimper. Strip off the jacket of the wires. When you remove the cover, you will be able to cross them over. Flatten them out and make all of the wires even. Then, trim the wires with a cutter. Attach a RJ45 connector to the wires. Carefully place it on the end of the wires. Use your crimper to crimp it. Now, it can also be used as a cross over cable. It's use has been altered.