All,
I was pointed to this logic circuit simulator on another forum:
http://ozark.hendrix.edu/~burch/logisim/index.html
It seems pretty powerful, and is open-source and written in Java. Maybe it might help someone out there to learn digital logic design, or maybe debug ideas. It is mainly meant as a teaching tool; it isn't meant to act as a real circuit simulator.
I did a search for "Logisim" on the forums here; I did find one mention (on the Italiano sub-forum):
...just for completeness.
Sounds good. I am not sure if there is a need for a digital circuit simulator any more since most logic is done inside a microcontroller or Arduino now. An analog circuit simulator would be very useful - LTSpice seems very popular.
I found this simulator - virtual breadboard http://www.virtualbreadboard.com/ which looks good and costs $29. Not sure what it does but apparently it can simulate an Arduino. Fritzing.org apparently is a very good circuit simulator.
A popular Arduino simulator is the iPhone app - Arduino Simulator but the comments are not very flattering. More like a training video.
Speaking of simulators, has anyone tried emulino http://hewgill.com/journal/entries/507-emulino-arduino-cpu-emulator or ardemu.
And of course, there is the Simulator for Arduino http://arduino.com.au/Simulator-for-Arduino.html a free or paid download.