Hi, new to the forums here. I hope somebody can offer me some tips - I just got a Sunpak Auto 221 flash with my camera but I have no idea how to use it with my cameras (Pentax K1000 and Olympus OM-1n). The back of the unit has a batt on/off switch and another switch with a white 'M', a yellow 'A' and a green 'A'. There's a gauge reading feet and f-stops, but I have no idea what its telling me. Any help is greatly appreciated. Thankx in advance. Also, there is some wiring exposed on the back of the unit. Is it something I can just cover with electrical tape or should I try to find a permanent solution? Thankx!