Where can I get this unusual screwdriver?

I was thinking of taking apart my old Game Boy Pocket for fun, but all of the screws are non-standard, three-slotted types of screws. I’ve looked around and most standard screwdriver tips have either one slot (flat head) or four (Philip’s head). Any tips on getting ahold of this type of screwdriver tip? Or is there a way of loosening the screws without a screwdriver at all?

I’m sorry I can’t find a picture of the screws, but basically they have slots that look like the symbol for radioactivity. I’ll update this if I find a good picture.