How Do I Connect a Trackball to a PC for MAME?

[LasVegasIRA]

I have a Missile Command cabaret that I've been trying to get working but the board is giving me problems. I'm thinking about installing a small PC with MAME to play the game for now, but I'm not sure how to connect the existing trackball to the PC.

Anyone know how I can do this?

[BadMouth]

With an interface board:

Cheapest:
Shows up as mouse and has inputs for 3 mouse buttons. http://groovygamegear.com/webstore/index.php?main_page=product_info&cPath=76_85&products_id=260

Others:
http://www.ultimarc.com/optipac1.html
http://www.twistedquarter.com/index.php?main_page=product_info&cPath=113_124&products_id=826

U-HID nano will show up as multiple devices (mouse and keyboard) to give you a few more button inputs, but requires configuring with ultimarc software:
http://www.u-hid.com/home/uhid_nano.php

There are others out there as well as using a teensy board....