555calc has pre-programmed solutions to the 555 timer I.C. Enter values for R1, R2, C1 and instantly display the oscillator frequency or the on time and the off time. Enter frequency or times and resistor value(s) and get the capacitance. No need to re-enter values to see the effect of changing one value. 555calc also has instant resistor color code display. Enter the resistor value and display the nearest color code for each band or enter the colors and display the resistor value. 555calc is a four function calculator with nine memories and instant square root and cube root. Note: above screen shot does not represent actual screen on Palm. The color distortion was caused by limited file upload size.