I have a PSX/N64 usb adapter from 4triangles.com and I can't get it to work properly with my comp. supposedly, all recent OS's should had drivers built-in for HIDs. I'm using OSX 10.5 I'm trying to use my N64 controller for tony hawk and an emulator. when i go to the joystick set-up menu in the games, it wont' register the buttons. I know the controller is good because it works fine on my console. any ideas?

Have you checked to see if the computer recognizes the controller?

I saw that you mentioned your running osx. I had this same problem with joybox 2 psx controller adapters. Its because your running a macintosh and does not support your drivers. if you would like to get it working anyways try using "bootcamp" for mac os x. It is a free homebrew download that has worked for other mac users.
Google Search= bootcamp for mac os x

i'm am indeed running osx..... but on a G4 processor. but, I got it all to work by running a program called gamepad companion.