Ngspice is a mixed-level/mixed-signal circuit simulator. Its code is based on three open source software packages: Spice3f5, Cider1b1 and Xspice. The simulator is GPL licensed and runs on most platforms. It is shipped as source code, but there are binary packages for Microsoft Windows and it is included in some Linux distributions. If it is shipped with your distribution the shipped macros will run without any adjustments. Also it will run on Windows without adjustment, if you uncompress it in the same folder level as your LayoutEditor installation (see below). Please check the file permissions, if you install it in the 'Program Files' folder. In all other cases you need to adjust the macro to your installation path. Three macros for ngspice are shipped: trigger the simulation with waveform viewer, trigger the simulation with text output and view only the ngspice netlist. You will find these macros at the menu item Utilities of the SchematicEditor and TextEditor.

Let's take a little simulation example and demonstrate what the single scripts do:

The script macro Simulate & Probe will trigger the simulation with NGspice and display its simulation report in the integrated TextEditor. Further more it will set the SchematicEditor into the Probe Mode. In that mode you can click on a node and the signal of that node will be displayed in a PlotViewer. PlotViewer options can be set by performing the click while the shift key is pressed. Mouse wheel and the right mouse button can be used to zoom into the plot in the same way it is available inside the schematic window or layout window.

In case the signal cannot be correlated with the simulation results a selection of available signals will be shown:

The script macro Simulate & Waveform Viewer will trigger the simulation and display the ngspice console with its own waverform viewer:

And finaly the script macro View Netlist will display the spice netlist for NGspice inside the integrated TextEditor. Inside the TextEditor the simulation can be triggered once more via the menu for NGspice.