v4.3 [Oct 21, 2012] 
Version 4.3 includes the following features:
Calculation of 555 timer duty cycles < 50%
Calculation of LED resistor power dissipation
Option to calculate resistor for multiple LEDs in series
Capacitor code calculator lock-up bug in V4.2 fixed
v4.2 [Feb 20, 2011] 
Version 4.2 includes the following new features:
 * New 555 timer, voltage regulator & RC filter calculators
 * Enhanced series / parallel resistance & capacitance calculator
 * Calculation of preferred capacitor values with a choice of series from E6 to E24
 * Full compatibility with Windows 7 32-bit & 64-bit
 * Other enhancements & bug fixes
                    Electronics Assistant performs various calculations regarding electronics units