I want to be able to transfer programs but my machine does not have an rs232 the original owner gave me a plug with 4 wires tied together and it is marked csr. One of the boards inside the cabinet is marked csr but I'm not sure if I'm supposed to plug it in there or somewhere else. I've posted some photos of what I am dealing with.
What you have shown in photo 5 looks like someone's attempt at replacing the typical 25 pin socket used for RS-232. Check the wiring to this plug against the electrical manual.