Posted by =-JacK-= on September 13, 1999 at 23:10:02:
I recently acquired a spinner from a junked-out Major Havoc and a 2 ¼ trackball from a junked-out Missile Command, complete with optical encoder circuit boards and Molex plugs. A schematic of the encoder can be found at: http://www.geocities.com/SiliconValley/Lakes/9862/encoder.html . Here is what I want to do:
I use a hacked keyboard for my arcade control interface. I want to develop a circuit to turn the quadrature signal of the optical encoders into a “open/close” signal that I can wire into my keyboard to simulate a keypress. My idea is to leave the spinner and trackball OEM and not have to mess with analog sensitivity in MAME. I am more of an electrician than an electrical engineer, so I feel I can build the circuit, just not design it. I realize HAPP sells a serial port interface kit, but I really want to keep my inputs on the keyboard.