This mod came about from a failed SNES control pad mod that i made. Basically i tried to rewire a SNES control pad to a USB keypad to use with emulators but it had quite a few problems (due to the amount of buttons and the fact that the emulator uses numbers to turn on and off backgrounds, animations etc..)

Anyway this works fine with the atari joystick since theres only a direction pad and a 'fire' button. I used a usb keypad which cost me $5 from a local 'cheap' shop.
 

Retrobrad has been created and maintained by me - Brad!
This page has been visited times since June 2007

by retrobrad 15 July 2007
  Grab your joystick and open it up (theres just four screws)  
  Your going to need a USB keypad and an atari joystick (or similar) You will also need a soldering iron, solder, wire, stanley knife, some tape and glue  
  Once it is open, pull out the circuit card - it will look something just like this photo. you can now disconnect the old wires (just pull them off)  
  This is what it should look like at this stage.  
  Alright, now you need to solder the wires from the keypad, to the joystick circuit card.  
  It's time to get the joystick circuit card and configure it to accept the keypad wires. So that involves cutting tracks and connecting shorting links where necassary, but again this will depend on your keypad.

Heres one of my cut tracks ----->
 
  Okay now you have figured out where the wires go you need to actually solder them in. Oh by the way, i have removed the keypad connector in this photo ------->  
  Now open up your USB keypad and disconnect the circuit card from the keypad. (hopefully your keypad has a really small circuit card like this one.)

This is where you need to use your own brain = ) You need to figure out what wire is going to go where. you will need to use a total of five keys for your control pad. I used the 7/home key, up/8 key, the 9/PgUp key, the * key and the / key. It doesn't matter where they connect to on your joystick because you set them up in the emulator.

To figure out what wire will go where you need to take the plastic membrane from the keypad and trace each track to figure out where to solder your wires. NOTE: some wires will be common (eg one half of the 7, 8 and 9 keys are connected together.)
 
  Okay it's now all put together and ready to play some pitfall on my laptop!  
  For an extra touch, i added a blue LED to it just to show that the device has been recognised and it is working. To do this just solder one wire of the LED to USB ground and the other through a series resistor to USB +5v. a good value resistor would be about 1k ohm.