I have two keyboards. one is qwerty, one dvorak. I keep them both plugged in. causes problems with startup combos, but no big deal. it is actually quite useful.
If i have another person over, and try to play MAME or other games, then theres more than one keyboard. unfortunatly, the mac only sees one. when a button is pressed simultaneously on both keyboards (different buttons of course), it only responds to one, sending the other player into a wall or off a cliff. in quick response games, this is infuriating and can lead to a little cheating.
USB macally and apple imac type "you don't need those keys" keyboards, different usb ports. How can I get my mac to see different keyboards, or just to respond to more than one key being pressed at once?