Gnucap Projects

Here is a list of some of the projects that need to be done. There are many more not listed here. If you are interested in any of these, or have other ideas not listed here, contact us.


We desperately need models. We have the basic MOSFET, but still need specific mosfets like BSIM4, BSIM-SOI, EKV, and others. Some of these can be derived from the Spice models. Others need to be coded from scratch. We need full models of other devices, like BJT's, thyristors, and tubes. We also need passive devices, like coupled lossy transmission lines. The model compiler makes this job much easier than for other simulators.

Finding existing models

There are lots of models and data available now. Many generic Spice models work with Gnucap. Verilog-AMS and VHDL-AMS models will work when support for these languages is added. We would like to have aweb page that refers our users to the models that are available other places.


Next to the models, we need libraries containing macro models of various devices. Some of these are available now, perhaps in the syntax of a proprietary simulator. The ones that work need to be referenced. The ones that don't need to be translated.

Other types of analysis

It is not just AC, DC, and transient. We also need to do RF circuits. This means some way to do steady state nonlinear. We also need noise and distortion analysis.

Web pages

The web pages you see are just a start. We need an FAQ, pointers to models, pointers to technical information, and lots of other stuff.

Graphic postprocessor

A table of data is not good enough. An ASCII plot isn't either. We need something that lets you view and manipulate graphics. This should be a separate exectuable.

Control shell

We need something with control structures, like a modern shell. We need something that can do loops and conditionals.

Interfaces to other software

There are numerous other related software packages, including schematic entry, layout, and extraction. We need interfaces. Some of them already interface through a translator. We need more direct interfaces that look seemless to the user.

Competitive analysis

Even if you are not a programmer, you can still contribute by helping with a competitive analysis. We need a checklist, showing advantages and disadvantages. We will use the disadvantages to influence future development, and the advantages for bragging. You can help even more by providing a detailed specification of something you would like to see in Gnucap.


There are numerous textbooks aimed at undergraduate education that show how to do circuit analysis using some commercial simulator. We need that for Gnucap!

Please send FSF & GNU inquiries & questions to There are also other ways to contact the FSF.

Please send comments on these web pages and Gnucap to

Copyright (C) 2001 Albert Davis

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Last modified: Thu Jan 22 15:59:48 EST 2004