Hardware Hacking Projects for Geeks

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Part II: Advanced Hacks, Tools, and Techniques

Begin by opening up a sample file, and place a bunch of known characters

for each port. Run the KE72LOAD.EXE program and open Notepad. Now

just start pressing keys, and write down what you see on the screen for all

the Player 1 and/or 2 and MISC buttons. Once you’ve completed this step,

it is a simple matter to track down which character you assigned to which

port and to begin replacing that character with the MAME characters. If

you like, you can trace all the wiring back into the ribbon cable and all the

way down, but this can be tedious and error-prone. When you press the

keys and observe the results, you’re guaranteed to know which

port connects to what.

Once you’ve programmed all the keys, spend some time check-

ing out a few games and playing around with the config file.

It’s probably a good idea to go into the TAB configuration in

MAME and set up all the files (even if you basically use all the

same keys) for the General Control. For example, in games

that use two joysticks for one player control, like BattleZone

and Bezerk, MAME doesn’t use the Player 2 joystick as the

Player 1’s right joy. So go into the General Control and change

it so that all two-joystick games will be set up this way. Also,

MAME doesn’t have Player 2 buttons 5 to 10 assigned to any

keys. This can be fixed here also. Once you’ve completed this,

all of these games should play well by using the Player 1 joy as

the left control and the Player 2 joy as the right.

If you want more of an authentic feel, you can mount a button

on the front door for the “Game Start” signal.

5. Install the monitor and PC

The monitor should slide into the shelf with the holding blocks

you built previously. The PC case should fit into the space

under the control panel; the door you built will allow easy

access to it. See Figure 11-15. The cabinet should have plenty

of room for your other video game systems as well.

After you have installed and tested out the PC, close up the

doors and you are ready to go. The interior will look something

like Figure 11-16.

Troubleshooting

If you find that the keyboard wiring is not working, there are some things to

try. Carefully inspect the ground wires. Make sure all of your connections

look good. Next, use a multi-meter set to measure resistance. Check that

each of the signals from the encoder board goes to the switch you think it

does. Inspect each solder and crimp connection.

Figure 11-16: Front view of PC

Figure 11-15: Back view of PC

Troubleshooting

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1/22/2002 4:40:38 PM