A-D Converter For Joysticks

From an idea by F Berben Although joysticks come in an astounding variety of versions, their internal organization is vir- tually always a standard con- cept, based on either a set of relatively fragile, springy, mem- brane contacts, or two poten- tiometers. Many computer en- thusiasts will agree that the latter, analogue, type offers bet- ter reliability and quality. Unfor- tunately, however, these can not be used in conjunction with a popular home micro such as the Commodore C64, and that is where the present circuit comes in. The four comparators in ICI function as switches to translate the handle movement into digital signals. The outputs of the comparators are buffered in 1C2 to enable interfacing to the computer"s joystick port. The two remaining inverters in 1C2, NS and Ns, along with two inverters in IC; function as drivers for the LEDs that indi- cate the handle position. Gates li9-N12 are set up as a wired NOR function to enable LED D5 to light when the joystick handle i...