Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.2.0. Perhaps most notable in this new release is a much-larger library of components for input and output, but the new release also sports some interface enhancements and some bug fixes.
The new components for circuit input include a component for reading keys typed at the keyboard as well as a component that works similarly to a joystick. New output components include a dumb text terminal, a LED matrix, and a 7-segment display that displays four-bit values as hexadecimal digits. This new release also enhances the built-in flip-flops and registers so that they can optionally be level-triggered or edge-triggered in either direction.
Usability enhancements include a new area in the main window where one can quickly zoom in and out of the circuit. Also, the user can now rearrange the circuits in a project via a menu bar - or a new toolbar associated with the explorer pane.
Educational institutions around the world use Logisim as an aid to teaching about digital logic and computer architecture. As a Java application, Logisim can run on most major operating systems. Read more about Logisim at http://www.cburch.com/logisim/, and download it from SourceForge.net at http://sourceforge.net/projects/circuit/.