odd ea , Jul 20, 1998; 08:38 p.m.
Don't know about battery type, EM's not here right now, but:
1) Tiny button above lens release button is a backlight compensation switch. Hold it in while taking the picture and you will get +2 EV from the metered value.
2) This tiny button is the battery check button. Push it in and the LED should glow brightly indicating a good battery.
3) Tiny silver button (this is beginning to sound like an Infocom adventure game!) in base plate disengages the film from the wind-on sprocket. Click it in when you rewind the film or else you'll rip up the film by the sprocket holes! This also provides pseudo-multiexposure capability; push it in, wind the film advance and take another shot to double expose.
4) ISO setting does not click on mine either. This is quite convenient, as you can thus smoothly add/subtract exposure from the metered value by adjusting the film speed dial. (Remember to reset it when you are done, though). This allows very quick and convenient bracketing of exposures!
A great, albeit simple, camera. I've had mine for several months as a second body to an F90X and have enjoyed it a lot.