Logisim is an educational tool for designing and simulating digital logic
circuits.
Features:
* It is free! (Logisim is open-source (GPL).)
* It runs on any machine supporting Java 1.4 or later; special versions are
released for MacOS X and Windows. The cross-platform nature is important
for students who have a variety of home/dorm computer systems.
* The drawing interface is based on an intuitive toolbar. Color-coded wires
aid in simulating and debugging a circuit.
* The wiring tool draws horizontal and vertical wires, automatically
connecting to components and to other wires. It's very easy to draw
circuits!
* Completed circuits can be saved into a file, exported to a GIF file, or
printed on a printer.
* Circuit layouts can be used as "subcircuits" of other circuits, allowing
for hierarchical circuit design.
* Included circuit components include inputs and outputs, gates,
multiplexers, arithmetic circuits, flip-flops, and RAM memory.
* The included "combinational analysis" module allows for conversion between
circuits, truth tables, and Boolean expressions.