===== PC Engine / TurboGrafx 16 Controller =====
The PC Engine uses the same chip as the [[megadrive_genesis_controller_3|Genesis 3-button pad]]: the [[chips:74157]].  Basically, the console sends a high/low signal on a select line, triggering four different signals.  The buttons (I, II, RN, SL) are returned when the select line is LOW, the d-pad is returned when select is HIGH.

All the TG and most of the PCE pads also had auto-fire, which required the use of another chip: the [[chips:74163]].  This simple binary counter is advanced by the select line, and every fourth or eighth 'pulse' it activates the I and II buttons, effectively creating two rapid-fire speeds.

{{ controls:pcengine_pad_schematic.png }}