> But, still the issue persists that the increments are in the order of 4, = decrements > too.. I haven't worked through the code, but the coder could be using every edge = as a count, thereby getting a 4x resolution, but only updating the counter = on a certain edge. Does this make sense to how you work through the code? --=20 Scanned by iCritical. --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .