The Simulate menu

Simulation Enabled

If checked, circuits viewed will be "live:" That is, the values propagating through the circuit will be updated with each poke or change to the circuit.

The menu option will be automatically unchecked if circuit oscillation is detected.

Reset Simulation

Clears everything about the current circuit's state, so that it is as if you have just opened the file again. If you are viewing a subcircuit's state, the entire hierarchy is cleared.

Step Simulation

Advances the simulation one step forward. For example, a signal may end up entering a gate during one step, but the gate won't show a different signal until the next simulation step. To help identify which points in the overall circuit have changed, any points whose values change are indicated with a blue circle; if a subcircuit contains any points that have changed in it (or its subcircuits, recursively), then it will be drawn with a blue outline.

Go Out To State

When you delve into a subcircuit's state via its pop-up menu, the Go Out To State submenu lists the circuits above the currently viewed circuit's state. Selecting one displays the corresponding circuit.

Go In To State

If you have delved into a subcircuit's state and then moved back out, this submenu lists the subcircuits below the current circuit. Selecting one of the circuits displays the corresponding circuit.

Tick Once

Steps one tick forward into the simulation. This can be useful when you want to step the clocks manually, particularly when the clock is not in the same circuit that you are currently viewing.

Ticks Enabled

Starts automatically ticking the clock. This will have an effect only if the circuit contains any clock devices (in the Base library). The option is disabled by default.

Tick Frequency

Allows you to select how often ticks occur. For example, 8 Hz means that ticks will occur eight times a second. A tick is the base unit of measurement for the speed of clocks.

Note that the clock cycle speed will be slower than the tick speed: The fastest possible clock will have a one-tick up cycle and a one-tick down cycle; such a clock would have up/down cycle rate of 4 Hz if the ticks occur at 8 Hz.


Enters the logging module, which facilitates automatically noting and saving values in a circuit as a simulation progresses.

Next: The Window and Help menus.