Vensim is available in a number of configurations: Vensim PLE, Vensim Vensim PLE Plus, Vensim Professional, Vensim DSS, Vensim Runtime, Vensim Model Reader and Vensim Demonstration. Some configurations are also available with double precision computation and/or file scrambling. This statement applies to each configuration unless otherwise noted.
Vensim is or has been available for a number of operating systems: Window 3.1, Windows 95/98/NT (Intel and Alpha), Macintosh, Power Macintosh, AIX and Ultrix. These statements apply to all platforms unless otherwise noted.
Vensim has had a number of releases including 1.51, 1.60, 1.61, 1.62, 3.0, 4.0, and engineering revisions thereof. These statements apply to all versions of Vensim unless otherwise noted.
Date Entry and Display
Vensim does not use dates with the exception of a floating point to date conversion facility that can be used in Venapps with the DATE and EDATE controls. This functionality is available in Vensim DSS, Vensim Runtime and Vensim Application Runtime. This facility uses four digit dates. If a two digit date is entered 1900 is added to the date. Because dates are converted to floating point numbers values entered are subject to rounding errors. There is no adjustment made for leap years in this conversion.
Vensim uses the system date of the computer to record model information that is stored in models and datasets. The method that Vensim uses to retrieve this date will give an invalid result after January 18, 2038. For Versions of Vensim prior to 3.0 the software will not operate after this date. For version 3.0 and higher only the compiled simulation feature of Vensim DSS is affected. This problem will be corrected in version 5.
16 bit Code
The versions of Vensim available for Windows 3.1 are 16 bit programs. For all other platforms Vensim is compiled as 32 bit programs with no dependence on any 16 bit code that is not part of the operating system. The installation program for the Windows 95/98/NT versions of Vensim is a 16 bit program. Vensim will stop using a 16 bit installation program for Windows 95/98/NT beginning with version 4.0.