ACS
Al's Circuit Simulator

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

ACS is an ongoing research project. It is being released in a preliminary phase in hopes that it will be useful and that others will use it as a thrust or base for their research. I also hope for some comments that may help me direct my research.

• "Fit" function has choice of fit order and extrapolation. You can have order 0, 1, 2, or 3.
• "Posy" has even and odd options, to determine what happens in the negative region.
• Modelgen improvements. It now is useful for the whole device, sometimes. It now handles probes and the device side of the model. The diode uses it completely. There are still a few missing features needed for the MOSFET and BJT.
• Spice-3 compatible semiconductor resistor and capacitor.
• "Table" model statement.

Improvements, bug fixes, etc.:

• Option "numdgt" really works.
• Better error messages from modelgen.
• Code changes for optimization of commons. This should reduce memory use, sometimes, by sharing commons. Common sharing is still not fully implemented.
• Fix two bugs that sometimes caused problems after a "modify" or on a "fault".
• Better handling of "vmin" and "vmax". It should be much less likely that limiting causes convergence to a nonsense result.

Please see the current release notes for more info.