Module Name:	pkgsrc
Committed By:	dmcmahill
Date:		Sun Mar 26 15:50:22 UTC 2000

Modified Files:
	pkgsrc/cad/acs: Makefile
	pkgsrc/cad/acs/files: md5
	pkgsrc/cad/acs/pkg: PLIST

Log Message:
Update to acs-0.26.  Changes (from ${WRKSRC}/doc/relnotes-026) are:

New features:

1. BSIM1, BSIM2 models -- DC only.
2. New elements:
        trans-capacitor
        voltage controlled capacitor
        voltage controlled conductance
        voltage controlled resistor
3. Optional new syntax, with type first so component labels can start
with any letter, and the choice of components is no longer limited by
the 26 letters.  This was necessary for a clean syntax
for #2.
4. Some new parameters on existing devices, also a side
effect of the BSIM work.
5. The manual in HTML form.  The manual source is still in LaTeX,
which can be used to generate HTML, PDF, Postscript, or many other
formats.

Bug fixes:

1. An error causing truncation error to be underestimated has been fixed.

Other improvements:

1. MOSFET model evaluation is a little faster, due to use of one of
the new elements to replace several old ones.  I have seen 40%, but
20% is more likely.  The improvement is most evident on busy circuits,
where the ACS speed enhancements based on latency exploitation
contribute more overhead than their value, that is .. the type of
circuit that has run faster in Spice than ACS.

2. More documentation on internals.

Changes that I think are improvements, but some may disagree:

1. Truncation error based step control is disabled when Euler's method
is selected.  The justification for this is that the reason for
selecting Euler's method is to avoid the artifacts of high order
methods on "stiff" poles.  Without this change, a "stiff" pole would
cause an unreasonably small step size.  This did not appear to be much
of a problem in the old release because the use of an incorrect
formula for estimating truncation error.  A "stiff" pole is one that
has a response so fast it can be thought of as instantaneous.

2. The "help" command, with its 4 year old help file, has been
removed.  The concept is really obsolete.  With the HTML form of the
manual, a full online manual is a better replacement.


To generate a diff of this commit:
cvs rdiff -r1.1.1.1 -r1.2 pkgsrc/cad/acs/Makefile
cvs rdiff -r1.1.1.1 -r1.2 pkgsrc/cad/acs/files/md5
cvs rdiff -r1.1.1.1 -r1.2 pkgsrc/cad/acs/pkg/PLIST

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.