AQ: Popularization of SPICE
I am currently writing a bullet point history of the popularization of SPICE in the engineering community. The emphasis is on the path SPICE has taken to arrive on the most engineering desktops. Because of this emphasis, my history begins with the original Berkeley SPICE variants, continues onto PSpice (its limited, but free student version made SPICE ubiquitous) and culminates with LTspice (because, at over three million downloads, it has reached many more users than all other SPICE variants combined).
I have contacted Dr. Laurence Nagel (the father of Berkeley SPICE) and Mike Engelhardt (LTspice) in order to verify the accuracy of the historical account (haven’t had a chance to fold in Dr. Nagel’s corrections yet), but I am lacking solid information about the beginnings of PSpice (I don’t even know who the technical founders of MicroSim were). Ian Wilson was an early technical V.P. Also, I am not sure what the PSpice acronym means. (Seems to me that it started out as uPspice?)
Here is what I have recently found about PSpice (more info appreciated):
User’s Guide to PSpice, Version 4.05, January 1991
From Chapter 1: INTRODUCTION, Section 1.1 Overview, starting with paragraph 2 (page 3):
“PSpice is a member of the SPICE family of circuit simulators. The programs in this family come from the SPICE2 circuit simulation program developed at the University of California at Berkeley during the early 1970’s. The algorithms of PSICE2 were considerably more powerful and faster than their predecessors. The generality and speed of SPICE2 led to its becoming the de facto standard for analog circuit simulation. PSpice uses the same numeric algorithms as SPICE2 and also conforms to the SPICE2 format for input and output files. For more information on SPICE2, see the references listed in section 13.2.1.4 (page 427, especially the thesis by Laurence Nagel.
“PSpice, the first SPICE-based simulator available on the IBM-PC, started being delivered in January of 1984.
“Convergence and performance is what sets PSpice apart from all the other ‘alphabet’ SPICEs. Many SPICE programs became available on the IBM-PC around mid-1985, after Microsoft released their FORTRAN complier version 3.0. For the most part, these SPICEs are little modified from the U.C. Berkeley code. Using benchmark circuits, we find that PSpice runs anywhere from 1.3 to 30 times faster than our imitators. In the area of convergence, PSpice has a two-year lead in improving convergence and a customer base that is larger than all of the other SPICE vendors combined (including those SPICEs offered for workstations and mainframes). This larger customer base provides more feedback, sooner, than any other SPICE program is likely to receive.”
From Chapter 1: INTRODUCTION, Section 1.4 Standard Features, last paragraph (page 7):
“PSpice, version 3.00 (Dec. 1986) and later, is a complete re-write of the simulator into the ‘C’ pro-gramming language. It is not a version of SPICE3, from U.C. Berkeley, which is also written in ‘C’. MicroSim has overhauled the data structures and code, however the analog simulation algorithms are similar and the numeric results are consistent with SPICE2 and SPICE3. Having the simulator re-written in ‘C’ allows faster development, allowing our team to reliably modify and extend the simulator in sev-eral directions at once.”
From the January 1987 Newsletter: PSpice went from version 2.06 (Fortran) to version 3.00 (C). Speed increased by 20%. PSpice 3.01 (Dec 86) introduced the non-linear Jiles and Atherton core model.
From the April 1987 Newsletter: PSpice 3.03 (Apr 87) introduced ideal switches.
From the July 1991 Newsletter: PSpice announced Schematics at the June 1991 Design Automation Conference. (Became available when PSpice 5.0 shipped in July 91?)
Solving Differential Equations with Mic
