Digital is a cross-platform, digital circuit simulator.

These are the main features of Digital:

• Visualization of signal states with measurement graphs.
• Single gate mode to analyze oscillations.
• Analysis and synthesis of combinatorial and sequential circuits.
• Simple testing of circuits: You can create test cases and execute them to verify your design.
• Many examples: From a transmission gate D-flip-flop to a complete (simple) MIPS-like single cycle CPU.
• Contains a library with the most commonly used 74xx series integrated circuits.
• Fast-run mode to perform a simulation without updating the GUI. A simple processor can be clocked at 100kHz.
• Supports large circuits: The "Conway's Game of Life" example consists of about 2400 active components and works just fine. Its possible to use custom components which are implemented in Java and packed in a jar file. See this example for details. Simple remote TCP interface which e.g. allows an assembler IDE to control the simulator. Direct export of JEDEC files which you can flash to a GAL16v8 or a GAL22v10. These chips are somewhat outdated (introduced in 1985!) but sufficient for beginners exercises, easy to understand and well documented. Also the ATF150x chips are supported which offer up to 128 macro-cells and in system programming. See the documentation for details.
• Export to VHDL: A circuit can be exported to VHDL. There is also support for the BASYS3 Board. See the documentation for details. The examples folder contains a variant of the simple CPU, which runs on a BASYS3 board.
• SVG export of circuits, including a LaTeX/Inkscape compatible SVG version (see ctan)
• No legacy code.
• Good test coverage (exclusive of GUI classes about 80%). Almost all examples contain test cases which ensure that they work correctly.