The Single Source (CRSTER) Model computes hourly concentrations of quasi-stable pollutants in rural or urban settings. The model is applicable to design, modification, and evaluation studies for New Source Review, Prevention of Significant Deterioration, other permit-related applications, and evaluations that require the mathematical simulation of effects from stack effluents of a facility. Up to nineteen collocated stacks can be considered. For various averaging times, impacts are calculated on a polar grid of one hundred eighty receptors which can be at heights other than plant grade provided no receptor exceeds the height of the lowest stack. This addendum gives model changes in conjunction with UNAMAP Version 6. New in this release is the addition of a default option for the automatic setting of variables and program switches for regulatory application of the model.