Spindle stop from G-code (M05)

My present HAL spindle start, stop logic is working as desired except M05 commands in my gcode files are ignored.

I can change the OR gate to a 4 input (personality 0x204), however I'm not sure what signal I would use to drive that 4th input, or if there is an overall more elegant solution for spindle control. Note: I always manually start the spindle before hitting the run button for gcode execution, so I don't really need G03, G04 capability.

Suggestions please.