Here are summarized the model changes since the version released on November 25, 2003 (version described in A. C. Robin, C. Reylé, S. Derrière and S. Picaud. A synthetic view on structure and evolution of the Milky Way, 2003, Astron. Astrophys., 409:523 [ADS] and erratum: 2004, Astron. Astrophys., 416:157)

• 2009 Jul 24: simulations are forced to stop when output file size exceeds 2 Gbytes or when CPU time exceeds 10 days
• 2008 Jul 21: web interface moved to another machine; model is now accessible though URL http://model.obs-besancon.fr/ ; bookmarks must be updated if they contain URL like http://bison.obs-besancon.fr/...
• 2007 May 30: added possibility to ask for the retrieving of the simulation results through http, instead of ftp.
• 2006 Aug. 17: An error was corrected in the "table and differential counts" mode which induced a limitation (to 19) of the number of channels in tables for colour indices and proper motions.
• 2005 Jun. 20: A bug has been discovered in the computation of the kinematics, potentially giving wrong values of the velocities of the thick disc in particular. The bug has been introduced on 2005, Feb. 17. All velocities should be disregarded but number of simulated stars and photometry are correct. The bug has been corrected on 2005, Jun 20^th at 11:56 CEST (GMT+2:00). Simulations made before 2005, Feb. 17 are correct.
• 2005 Feb. 28: correction of an error in the handling of the photometric system in the form ; since December 4 2004, when using the HTML link "new access to the model form " in the summary of the supplied parameters to submit a further simulation, the photometric system used was not properly kept ; this resulted in an error message ("SYSTEME PHOTOMETRIQUE NON DEFINI") in the simulation output.
• 2005 Feb. 22: radial velocities are explicitely constrained within range -999, +999 km/s
• 2004 Dec. 6: Added use of CFHT-Megacam photometric system. More informations are available here.
• 2004 Aug. 17: Previous to this date the external disc flare was improperly applied to the thick disc population. It has been removed. The error caused a slight increase (compared to what is expected without a flare) of the number of thick disc stars at galactocentric distances larger than 9500 pc at low galactic latitudes. The change is not more than 1% in counts of thick disc stars in the plane up to magnitude V=20. Nowadays the thick disc population follows the warp but does not flare in the external part. Please refer to the publication for details about the warp and flare values.
• 2004 Feb. 18: In the previous version the V-I colours of thick disc and halo white dwarfs were wrong (too red). Other colours and V magnitude were correct. This has been corrected since Wed Feb 18 21:15 CET (GMT+1:00).
• 2004 Feb. 10: the slope of the flare was incorrect in the parameter file. This error produced extra stars at large distances (> 10kpc) at low galactic latitudes in some user conditions (deep star counts). The proportion of extra stars was estimated to a few percent. It is correct since Tue Feb 10 11:42 CET (GMT+1:00).