Has anyone out there built demultiplexers for any console controllers? I ask this as I want to build a 6+ button gamepad interface (SNES or Genesis 6 button) for my arcade setup. Arcade games use one wire per button, unlike most all console controllers. I've gutted an original Genesis 3 button and NES controller and ran discrete wires for each button + ground. This can become a pain when trying to run more wires... (i.e. 13 wires).
If any of you out there have dealt with this before, and have solid solutions, let me know. Thanks.
If you do a search on this forum, you'll find info on hooking up Genesis (aka MegaDrive) controllers. Megadrive 3-button controllers use off-the-shelf chips, for any more than that you usually need to program your own microcontroller.
I saw code & instructions for a micro-based PSX decoder (on these forums, about a year ago from memory), but due to the number of pins on the chip they were using, it only had about 4-5 usable buttons. I guess you could move the program to a chip with more I/O pins (making whatever chip-specific changes necessary) and get the rest of the buttons working...
In other words, 3 buttons = easy, more = not-so-easy.
Not solid solutions, sorry, just pointers in the right direction.