Noise exposure in the vicinity of airports is an important environmental problem. This paper reports the computation of noise exposure forecast contours with a mini-computer. In order to reduce the memory capacity required, several simplifications for the input data such as the first order approximation of EPNL-slant distance profile are considered. A modified computing procedure for concave and convex parts of the contours is adopted. Some examples of the trade-off studies for noise reduction executed with this system are also included in this paper.