The roots of 20-sim go back to the early 70's. It all started at the University of Twente.
Technical University of Twente SIMulation (TUTSIM)
In the early 70's, at the Control laboratry of the University of Twente, software was design for the modeling and simulation of dynamic systems. The package, named Tutsim, was sold in the late 70's.The package supported block diagram and bond graph modeling. Both forms had to be entered using a text based input. During the eigthties some developments were done to port Tutsim from MS-Dos to Windows 2.0. After that the no updates were made anymore.
Computer-Aided Modeling Analysis and Simulation (CAMAS)
In the early 90's, at the University of Twente a new program was developed as part of the the Ph.D. project of Jan Broenink. The program was equiped with a graphical user interface and allowed the creation of models by bond graphs. The prototype name for this modeling and simulation package was CAMAS.
Modeling and Analysis eXpert system (MAX)
While CAMAS was all built around bond graphs, a new prototype package called MAX was built at the University of Twente to investigated object oriented modeling techniques and modeling by physical components / iconic diagrams. MAX was the result of the Ph.D. project of Theo de Vries, Arno Breunese and Johannes van Dijk (all supervised by Job van Amerongen and Peter Breedveld).
In 1995, Controllab Products BV. was established to start the commerical development of the software. The experimental package CAMAS was further developped to supporting modeling with equations, block diagrams, bond graphs and a mixture of these.
After extensive testing, in august 1995 version 1.0 of the software was commercially released under the trade name 20-sim (Twente Sim). The trade name refers to the origin (University of Twente) of the package and the region (Twente) were it was made.
- 20-sim 1.0: 1995, August 10
- 20-sim 2.0: 1996, January
It took some time to incorporate the object-oriented modeling approach of MAX into 20-sim. In version 3.0 this was done. Version 3.1 supported the iconic diagrams that were investigated with MAX. New toolboxes were incorporated in subsequent versions of the package.
- 20-sim 3.0: 1999, May 17
- 20-sim 3.1: 2000, June 6
- 20-sim 3.2: 2001, December 12
- 20-sim 3.3: 2003, February 23
- 20-sim 3.4 - 2003 December 24
- 20-sim 3.5 - 2004, November 10
- 20-sim 3.6 - 2005, April 5
The release of Windows Vista was used to give the package a major overhaul. Continuous improvements followed.
- 20-sim 4.0 - 2008 January 22
- 20-sim 4.1 - 2009, June 6
- 20-sim 4.2 - 2011, December 14
The release of 20-sim 4.3 was used to give Controllab a new corporate identity. This was reflected in the new logos of 20-sim and 20-sim 4C.
- 20-sim 4.3 - 2012, November 7
- 20-sim 4.4 - 2013, September 25
- 20-sim 4.5 - 2014, November 12
- 20-sim 4.6 - 2015, December 10
- 20-sim 4.7 - 2018, March 2