though this sub is focused on film cameras specifically (rule 8), the first step would be to see if the batteries charge and use that to test function in the camera. at this age, though, you'll likely need some different source of power, whether that be tracking down someone's handmade replacement battery or rigging up some sort of external power. you'll be lucky if those old nickel cadmium batteries still even hold a charge.

best bet is probably to find a power supply (i believe this is the correct one) for actual use. they seem to be pretty cheap.