Creating a Joystick-recognized Device

[tilky]

While my question is not relevant to FIRST, I'm hoping that somebody here might know the answer. I need to find a way to create my own joystick-recognized device, one that only has buttons. I know this is possible with microchips such as the Cypress that is used for the DS IO, but I wanted to keep it as cheap as possible. After doing some research, I came across an AT90S2313 microcontroller that is supposed to do the job. Did anyone else do this before and know of a good microcontroller to use? If not, can someone give a little insight as to the pin abbreviations used in the attached photo? Thanks in advance.