im currently using protel to draw circuit diagrams and it is fine for that. but, when trouble shooting a board, i'd like to have a schematic drawing program that would allow me to set my own input voltages and allow me to check the voltages at different nodes. the only components i need it to recognize are amplifiers and resistors. if it could do capacitors that would also be helpful, but i only expect to find programs that do DC calculations. i liked the way logicworks was set up, it allowed me to set the inputs and place probes everywhere i wanted to test the outputs, but that program was only for logic gates, and the voltages checked were 1's and 0's nothing more. any suggestions would be greatly appreciated.