Cable
I am guessing that your aircraft has a data plug that looks a bit like the NATO standard headset jackplug ?
What you require is a male type plug to fit this Jack and a standard 7 way D conector, once you have these you can make the cable to connect the KLN89B to your computer, it took me about a hour to construct this cable, the drawings can be found in the KLN89B instalation manual.
Talk to the guys at your Avionic shop, it s likely that one of them will construct a cable for you in his lunch hour if you offer a little cash.