If you are handy with tools, a 1N34A diode wired in series with a 1.5 silver oxide battery will drop the voltage to 1.3 volts. There several sites on the web which describe the procedure for an Olympus OM-1 camera. You can get a description about the polarity of the diode there. After reading the procedure installing one in a Yashicamat 124 should be fairly easy.