Sean Fahey wrote:
On Thursday, September 8, 2011 12:59:41 PM UTC-5, Michael J. Mahon wrote:Actually, 3 pushbuttons are easily supported on all 16-pin game-portedApple II's. It's the fourth pushbutton that is present only on the IIgs.How did the controller for this work? http://www.mobygames.com/game/pq-the-party-quiz-game/cover-art/gameCoverId,78777/
The pad buttons actually connect different valued-resistors to a paddle port. The Apple reads the paddle and decides whether and which button was pressed. This scheme was also used on the "Muppet Keys" and other "extended" keyboards for the Apple II, so it can be extended to many buttons. -michael NadaNet 3.1 for Apple II parallel computing! Home page: http://home.comcast.net/~mjmahon/ "The wastebasket is our most important design tool--and it's seriously underused."