Nothing special.  In fact it was one of my older PC's that I had retired to the den a while back.  It was a Pentium III running XP.  I crammed a little more ran into it.  The spec of this machine are:

• Pentium III 700 Mhz
• 512 MB of RAM
• Windows XP
• Generic Sound card
• Middle of the road video card
• AT case with the cover off to vent the heat better
• CD, Floppy, USB ports, etc

I mounted a shelf in the cabinet and screwed the PC down to one side.  The Keyboard rests inside on the shelf and the mouse was moved up top of the game, connected to a USB hub I put up there so I could connect a USB drive to it if I need to move files.

I also wired another push button switch (the same one as the coin slot switch) at the top of the rear of the game.  The job of this switch is to turn on the computer.  On the computer's motherboard there is a pair of wires that run to the push button switch that turns on the computer.  All I had to do was splice into this pair of wires extend the pair up to the switch on the back of the game.  Now I can turn it on without opening the coin door and reaching in.

Loading the MAME Emulator and ROMs is not a difficult task.  More on that later.

I used an older set of speakers with one speaker mounted up top over the hole that was the original speaker and the other speaker in front of the PC within the cabinet.  The one inside in front of the PC has the volume, bass, treble controls and is accessible through the coin door.

Access through the Coin Door

The key hangs behind the game.  To access the keyboard I unlock the coin door and lift the keyboard out.  The trackball mouse used to be behind the door but that was a pain because I had to leave the door open to use it for some games, so I moved it to the top of the game out of a hole on top.

The power to all the components in the game is supplied from a single power strip with an 8 foot cable running out the back.

In the MAME program, the 5 and 6 keys duplicate the coin drops.  The game had coin slots.  Dropping a coin trips a micro switch.   It was as simple as wiring these switches to the KeyWiz 5 and 6 inputs.  I also wired a push button to the 6 key (some games with a single coin slot use only the right coin slot or button 6 in MAME).  This button allows me to ring up games without a pocket full of quarters.  But having it take quarters is a major cool factor.