To make the arcade cabinet come to life we need to install a few pieces of software on the PC contained within. This will take some time to complete, but once the work is done the cabinet will be able to play just about any title from the golden years of the arcade.
You can use these instructions to turn your PC into an Arcade simulator. The keyboard won't offer the same experience as an arcade joystick, but the games will run just the same.
Install an Operating system
The operating system of your cabinet is only of minor importance. In most cases it is best to install the OS you are most comfortable with. A UNIX based OS may be free to purchase, but if you have never dealt with it, it can take some time to install and administer. Windows is just as capable and offers the possibility of hosting a large library of PC based games in addition to the arcade games.
Windows users should be aware that the OS will always display the Microsoft splash screen during the boot sequence. This breaks immersion for some, who do not want too see a PC screen on an arcade cabinet.
The core piece of software on the cabinet is MAME, the Multiple Arcade Machine Emulator. This piece of software emulates the hardware present in the original cabinets and allows the the games to run on the PC. MAME is available as a free download from mamedev.org.
MAME requires no installation per se. Simply extract the files contained in the archive into a directory. The emulator can be started by calling the main executable on the command line. To hide all the command line work form the user, we'll be installing a front-end user interface in a later on.
Configuring the Buttons
The OS will automatically find and configure the devices used in the cabinet's control panel as input devices. They may appear as a joystick, or a "Human Interface device". It's all the same to MAME. The application's configuration dialog allows you to configure the mapping between actions such as a button press, and an input device.
For example, to map the "Player 1" button to the appropriate event, simply select the event in the configuration dialog and press the "Player 1" button on the controller. Repeat these steps for all the other buttons. There is even an event for "Coin inserted". If you have installed working coin box on your cabinet, this is the event to connect it to.
Arcade games for use with MAME are called ROMs. Just about every arcade game that ever existed is available in ROM form for use with MAME. The challenge is finding the ROMs and downloading them in a legal way. The MAME website offers a few ROMs for free, but they won't keep you satisfied for long.
Finding a legal way of downloading the ROMs is very hard. The market for home-built arcade cabinets is too small for the game developers to offer ROM packages. A lot of cabinet owners download their ROMs illegally from torrent sites. ROM collections containing thousands of games are not hard to find.
Installing a MAME Front End
MAME by itself is not very user friendly. Games have to be loaded on the command line. A "front-end" application is needed to hide this complexity from the user. This app will let the user pick from a list of games instead of relying on text input.
There are several front-end applications available to choose from. Like MAME, most are free. My front-end of choice is Mala available from malafe.net. Installation and configuration steps vary from front-end to front-end. Follow the instructions that come with the application to complete your installation.
For only the cost of your OS license MAME turns your PC into a machine that can run every arcade game ever created. It takes a few extra steps to get MAME to be user friendly, but you'll be up and running in only a few minutes. MAME will even interface with your home-built control panel. You could even skip the cabinet built and run MAME on your PC.