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Welcome to the Gnucap home page!

Gnucap is the Gnu Circuit Analysis Package.

The primary component is a general purpose circuit simulator. It performs nonlinear dc and transient analyses, fourier analysis, and ac analysis. Spice compatible models for the MOSFET (level 1-8), BJT, and diode are included in this release.

Gnucap is not based on Spice, but some of the models have been derived from the Berkeley models.

Unlike Spice, the engine is designed to do true mixed-mode simulation. Most of the code is in place for future support of event driven analog simulation, and true multi-rate simulation.

If you are tired of Spice and want a second opinion, you want to play with the circuit and want a simulator that is interactive, you want to study the source code and want something easier to follow than Spice, or you are a researcher working on modeling and want automated model generation tools to make your job easier, try Gnucap.

New features in 0.35

  • Named nodes. (Extended beyond Spice compatibility)
  • Nested subcircuits. (Spice compatibility)
  • Parameters. ("param" statement, passing parameters to subcircuits) Parameters are variables, so you can change them at any time.
  • MOS level 8 and 49 models.
  • DC sweeps can be nested, for now up to 4 deep. (Beyond Spice compatibility.)
  • Autoconf based build system. The old build system is still available by running "configure.old".
  • Improvements to the transient analysis step control algorithm.
  • Improvements to the switch model, focusing on timing accuracy and convergence.
  • C++ language standard corrections, so it compiles with gcc 4.1.
  • News/Announcements

    September 20, 2006
    Version 0.35 released.

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

    Please send comments on these web pages and Gnucap to bug-gnucap@gnu.org

    Copyright (C) 2002,2003,2004 Albert Davis ad146@freeelectron.net

    Verbatim copying and distribution of this entire article is permitted in any medium, provided this notice is preserved.

    Last modified: Sat Oct 28 01:56:59 EDT 2006