An IBM cable with a RJ11 (telephone) connector on one end, and a full-size 5-pin barrel connector on the other end. Unicomp will sell you one of them.
A better plan is to use a Soarer (or similar) protocol converter and a USB cable so you can connect it to a modern PC and remap the layout to your liking.
- Ron | samwisekoi
Auto-typed by my GH-122 keyboard.