I finished making the schematic and would like to share the circuit I use to connect my consoles on the PC RS-232C port:
Due to the properties of LM339 (open collector output and wide range voltage input) this circuit will operate with an supply of +5V (Standard supply for MAX232 chip) while it *will* operate properly with any circuit as long the voltage for the circuit being interfaced to is supplied on the VREF input pin.
I've been using this device for about two years now and it never failed me(electronically wise).
The original one was starting to get old and was giving me headache with wires getting loose and other issues so I built a new one.
This is the exact circuit for the new one I recently built.