A simulator made to design and test logic gates circuits. This simulator can handle all basic gates, clocks, custom gates etc... Cycles can be formed in the circuits, opening the way for circuits containing latches for example.
This simulator is made in JavaScript so no installation is required.
Try it out: https://kubbydev.github.io/LogicGateSimulator/
This link leads to the generated version of the code (the version that went through Babel and a JavaScript minifier). The source code can be found in the Simulator folder in the repository's root.
Resources containing pre-made custom gates and example projects can be found in the Resources folder in the repository's root.
The simulator is designed to be as simple and easy to use as possible, but a user manual is always helpful.
There are 3 modes:
- Build: Create, move or destroy gates
- Wiring: Make connections between gates
- Interaction: Interact with some gates (switch between states or get information)
To switch between modes, one can click on the buttons on the top center of the screen or press B (build), W (wiring) or I (interaction).
When build mode is activated, there is a menu on the right with a list of all the gates that can be created. A gate can be created by clicking on it in the menu, and then clicking where the gate is desired to be placed. This menu contains basic gates (AND, OR, NOT, XOR, NAND...), and also some special gates and custom gates that will be explained later.
A gate can be destroyed by moving it on the Destroy button of by pressing Del with the gate selected.
Common gates can be placed with hotkeys: A (AND), O (OR), N (NOT), X (XOR)
The last gate that was placed can be placed again by pressing Space. Pressing shift will force the gate to be placed on one spot of a virtual grid.
When wiring mode is activated, one can start a wire by clicking on a gate input or output, and click on another gate to end it. A wire can be canceled by clicking where there is nothing.
Nodes can be used to redirect or split wires (Node is a gate available in the gates list but it transfers current instantaneously while other gates take one frame to update).
When interaction mode is activated, one can click on a gate to interact with it. Interactions will be detailed later, but in general they will either change the state of the gate (switches, clocks...), or get information about it (custom gates, clocks...).
Clock:
The clock will change its output every x frames (1 second = 1000 frames). It cannot take any input. Clicking on it in Interaction mode will open a popup to change the number of frames between 2 state changes and the current counter (Setting the counter can be useful to synchronize clocks while the simulator is paused).
Input:
Clicking on it will switch between on and off (Also used to mark inputs of custom gates).
Output:
Does nothing and does not have an output. It can be used as a sort of LED (Its real use is to mark outputs of custom gates).
Switch:
Clicking on it will toggle between opened and closed.
Custom gates are boxes that hide a circuit. They are simulated as if the internal circuit of the gate was in the simulator itself so it is possible to make latches inside custom gates. To create a custom gate, one can place input and output gates and connect them via some circuit. The input gates will be the inputs of the custom gate and the output gates will be its outputs. When the circuit is done, one can click create custom gate on the bottom left of the screen (in build mode) to start the custom gate generation process. This button will open a popup where the name of the gate and the names of its inputs and outputs can be chosen (inputs and outputs are ordered by height i.e. the ones on the top are displayed first in the name selection menu). Then pressing Done will make the simulator display the code to generate the custom gate and generate one automatically. It will also generate a save file (.lgs) that can be imported using the Import button.
The generation code of the gate can also be found by clicking on the gate in Interaction mode. The gate can then be generated as many times as needed with the Custom button in the gates list (in build mode). Generation codes can also be saved and shared as they are not dependant of a simulator instance. In fact there is a library available in the Resources folder.
The simulator state can be saved at any time using the Export button. It will generate a .lgs file and download it. Saves can then be imported using the Import button. The content of an import is always placed in the center of the screen without removing the gates currently in the simulator (The simulator can be cleared just by refreshing the page).
The default simulation speed is 1 update per millisecond. It can be controlled using the play/pause buttons in the top left corner of the screen. Press pause to pause the simulation, play to resume it. The forward one update button can be used to advance step by step when the simulation is paused. The right arrow key can also be used to advance several steps forward (1 step every millisecond).
The gif below shows a programmable 8-bit computer made to show the possibilities of the simulator. It is calculating the fibonacci sequence and returns to 0 when the maximum is reached (when it goes above 255). Better explanations can be found here: https://github.com/KubbyDev/LogicGateSimulator/tree/master/Resources/ExampleProjects/8-bit%20computer
