Diaphontein Solver is a tiny, totally free, mathematical utility that doesn`t need installing and runs under MSDOS.
The main function of Diaphontein Solver is to solve ax+by=c type equations. The number of possible solutions it obtains is difficult to do manually.
The Diaphontein Solver user simply has to give it the corresponding values for X and Y, and specify the interval range of the function. Once this data is in it, Diaphontein Solver will give you an exact solution for that equation with those parameters.