🚀 go-pugleaf

"ACS" (Al's circuit simulator) has been posted to alt.sources.

ACS is a general purpose mixed analog and digital circuit simulator.  It  
performs nonlinear dc and transient analyses, fourier analysis, and ac  
analysis linearized at an operating point.  It is fully interactive and  
command driven.  It can also be run in batch mode.  The output is produced  
as it simulates.  Spice compatible models for the MOSFET (level 2) and  
diode are included in this release.  Other models (MOSFET levels 1 and 3  
and BJT) are in the testing phase.

Since it is fully interactive, it is possible to make changes and  
re-simulate quickly.  The traditional batch approach of repeat(edit,  
simulate, wait) is a thing of the past.  This makes ACS ideal for  
experimenting with circuits as you might do in an iterative design or  
testing design principles as you might do in a course on circuits.

In batch mode it is mostly Spice compatible, so it is often possible to  
use the same file for both ACS and Spice.

The analog simulation is based on traditional nodal analysis with  
iteration by Newton's method and LU decomposition.  An event queue and  
incremental matrix update speed up the solution considerably for large  
circuits and provide most of the benefits of relaxation methods but  
without the drawbacks.

It also has digital devices, so it is a gate level logic simulator.  The  
digital devices may be implemented as either analog subcircuits or as true  
digital models.  The simulator will automatically determine which to use.  
Networks of digital devices are simulated as digital, with no conversions  
to analog between gates.  This results in digital circuits being simulated  
faster than on a typical analog simulator, even with behavioral models.

ACS also has a simple behavioral modeling language that allows simple  
behavioral descriptions of most components including capacitors and  
inductors.

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.  It may be copied as per the GNU  
General Public License.

ACS is available from a dial-up 716-272-1645.  Login as "guest".  Type  
"help" for a list of commands.

I plan to put it on an anon ftp site soon.  Details!.

al.