RCX and NXT communication

[Bill_B]

There is a legacy block available for NXT-g that will support the older rotation sensor. The cable you reference can connect the older rotation sensor to the NXT. The legacy block(s) can be found as patches at the Lego support site.

However, you mention wanting to control four motors with the NXT. I'm not sure how that's possible with only another rotation sensor. There are other, non-Lego, methods for gaining extra motor control from a single NXT. Perhaps you can be more specific about what you'd like to accomplish with your proposed configuration?