Amstrad's Lightpen ([[Amstrad LP-1 light pen]]).
And, various mouse interfaces ([[AMX Mouse]], [[Atari-ST mouse adapter]], [[dk'tronics Mouse Interface|Dk'tronics Mouse Interface]], [[CPC-Mousepack 2.0]], [[GEOS mouse|GEOS mouse]]).
On the original CPCs, the direction/button inputs can be reprogrammed as outputs (via PSG/PPI config). However, this will NOT work on the CPC+/GX4000's dual joystick ports - which include diodes (like normal joystick Y-cables).
== Joystick Related stuff... Sega Controllers... ==