Hello Friends

I have a 1984 Kitamura, MyCenter1 and the only thing now to get it running is the ability to communicate with a PC. I have read and looked at many threads regarding RS232 cables. I need to make a cable now. I haven't seen any threads for the 3M controller and RS232 communication. It does have a RS232 port on the side and I know it works. I bought it from a shop that still used the machine.

Do I need a null modem cable or a full handshakes?

I know I have seen a 25 pin to 25 pin cable diagram too. But I can't seem to find it again. So I am asking for help..