For fun, I'm designing a speed sensor interface for my TBI-equipped FSJ (7747). It converts the stock Cruise Command speed sensor's signal from 8 pulse/rev sine wave to 2 pulse/rev square wave for the TBI.
I successfully tested a breadboard version in the FSJ this afternoon.
Next I'll either etch a circuit board or have a few fabbed.
So, if you want one to try out, let me know.
The circuit uses a dual op amp as an active lo pass filter and amplifier. For now an ATtiny25 divides the incoming pulses to 4- and 2-pulse. I'll probably use a dual D flip-flop in a later revision.