Now, I mentioned elsewhere on the site how much of a big job this bit was. I'll try to explain as I go. What I decided to do was "hack" the keyboard. You play MAME games by pressing keys on the keyboard for up and down, fire etc. So the idea was to take a keyboard apart and find where I have to connect two points to generate a key press. Thing is, I had to do this for 25 different keys!

The first job was to take the keyboard apart, switch the computer on and watch the screen while I stab around randomly with a bit of wire. Actually, it wasn't that random, I had examined the PCB in the keyboard and I saw the connector was 16 by 9. This meant that I have to connect one of the 16 way terminals to one of the 9 way terminals to generate a key.

Using this and many hours trial and error, I managed to make a list of where I needed the various buttons to connect to.

You see how if I connect terminal L with terminal 8 it produces a letter Z. At the bottom of this drawing you will see a rough sketch of a keyboard with wires leading to a box. In that box is where all the magic takes place. I planned to put 2 big sockets on the outside so I could plug the control panel directly into it. First, I had to get all the wires into the keyboard and soldered on the right points in the matrix.

This is a diagram of where I decided all the button connections were going to be.

I know my soldering isn't that pretty, but it was a lot more difficult than I had anticipated. Anyway, on checking them with a DMM, I managed to get a beep from it when I pressed the keys, so it was working. I screwed it back together quickly before it fell apart.

Now I had to build the magic box, this is where all the connection are routed to the correct place.

I attached the sockets to the magic box, then started soldering the wires to them. I had the DMM and crocodile clips to check every connection at every step of the way, it all went very smoothly really. I desperately didn't want to make a mistake.


Here's some of the wires (A recycled IDE cable) attached to the larger plug.	This is a bit later on. You can see a couple of block connectors there, all these wires connect to the ribbon cables coming out of the keyboard through them.


There you go... all the wires connected, an electrical spaghetti junction in a box.	After standing on the box, I managed to get the lid on. I have no desire to open it again.

Now the interface is almost complete, it's time to start assembling the actual control panel. I bought some joysticks and buttons.

Look good don't they? This is just the first set. I bought a few more a while afterwards.

I got a shed load of colour coded wire and connected all the buttons with spade connectors.


Now the panel is assembled, and every connection that is made with the switches goes to the 37 way D plug. This connects to the magic box, the key presses are passed on to the keyboard.	A view of the panel from the top. Stainless steel. It should take a beating. Actually, I have thumped it a few times, it's as solid as a rock.


Before I screwed the D plug together, I just had to test it with a game. I connected it all up and spent hours playing a few games. I thought I would never get it finished.	A view of the panel from underneath when it's in position. I had to cut a little bit of wood away to make room for the joysticks. It made it a good tight fit as it turned out.

When I had finished wiring everything up, I had 2 controls that didn't work. In the end, I found the problem, Somehow I had got 2 red wires! All I had to do was swap them over and everything was fine! Over a year later, it's still all working 100%.