Skip to content
Choose a tag to compare

Unofficial build with spice4qucs features enabled. Release candidate 6

@ra3xdh ra3xdh released this
· 388 commits to qucs-s-stable since this release
Choose a tag to compare


This Release Candidate 6 (RC6) for Qucs with my unofficial patchset spice4qucs enabled by default. This RC6 contain a massive update and differs significant from previous ones (RC5 and earlier).

Main features

  • Introduced "Default simulator". You can select Ngspice, XYCE, or Qucsator as default simulation kernel and run desired simulator just pressing F2. If default simulator is not set, you will be asked to select it at the first run.
  • Every simulator has its own components set. Simulator-incompatible components become hidden.
  • Implemented DC bias calculation (by pressing F8) with SPICE.
  • Implemented XSPICE CodeModels support. CodeModels could be attached to schematic and compiled dynamically at simulation time. CodeModels could be also attached to libraries.
  • Added "Generic SPICE device" and "Generic XSPICE device" components. These components allow users to construct their own SPICE devices
  • Added "SPICE Library device". It allows to attach to schematic an unmodified SPICE library (*.lib) and use components from it using predefined symbol patterns (opamp_5t and opamp_3t are available)
  • Fixed different bugs with SpiceOpus simulator
  • Switched to binary raw-SPICE-3f5 datasets format to increase SPICE datasets processing performance for large simulation data.
  • Fixed general bugs
  • Synchronized with Qucs-0.0.19 mainline code

Documentation is available here:
Discussion thread is here: Qucs#77

How to install


There are no precompiled Linux packages (*.deb and *.rpm) and you need to compiled it from source. Refer to to install all necessary dependencies. You need C++ compiler, build tools, and Qt4. You need also to install ngspice and/or XYCE. Ngspice is shipped by the most of Linux distributions. For example:

apt-get-install ngspice

will install Ngspice for Debian-like.

If there is no previos Qucs versions installed you can unpack and compile as usual:

tar xvfz qucs-0.0.19S-rc6.tar.gz
cd qucs-0.0.19S-rc6
cd qucs
make install
cd qucs-core 
make install

If you already have other Qucs versions installed you may want to have two installations side-by-side. You need to use --prefix for GUI an core respectively switch in such case. You can set any desired directory (for example /opt) for Qucs-S package installation here:

./configure --prefix=/some_qucs_location/

If you are interested only in SPICE simulations, you need to build only Qucs-GUI. You can also use side-by-side installation of multiple versions with --prefix . Qucs will be installed in default /usr/local/ location, if this option is omitted:

tar xvfz qucs-0.0.19S-rc6.tar.gz
cd qucs-0.0.19S-rc6/qucs
./configure --prefix=/some-qucs-location/
make install


You need to use binary installer for Windows. You need to download and install Ngspice and/or XYCE manually from official websites: respectively.

It's recommended special attached build of Ngspice for Windows ( archive). But default Ngspice package also will work. Custom Ngspice build solves the following issues:

  • Windows GUI of Ngspice is disabled. It allows Qucs-S to obtain logs from Ngspice.
  • Added CMPP preprocessor and C headers set mandatory for development of CodeModel libraries. Default Ngspice build is shipped without it.

Verilog-A support on Windows

You need to perform some additional steps to make Verilog-A compiler work on Windows: