Thanks. My misfire started off random throughout the rev range. My wiring to the crank sensor comprised of a length of new wire from the edis soldered onto the last 100mm of the old wiring going into the sensor plug. I stripped the boot and the insulation off the old wiring but found no problems but replaced it anyway. I replaced the edis module and whether it was coincidence the misfire stopped being random and only appeared at around 4000 revs. If I accelerate slowly though that point the misfire doesn't happen so I put it down to a car problem (running Fireblade carbs with one of the air corrector jets blocked off).
Snapper, I never thought of the square wave requirements so I'm going to change both the sensor, plug and screened cable and see what happens. Hope I can get this done before sorning it in October!