Wouter van Ooijen wrote: > 2 You think strobing a 7-seg is time critical? Indeed. You think it is not? One thing that I discovered when working with those 4-character alphanumeric LED displays from HP (used on a high-end telecom product) was that the slightest variation in refresh timing caused very visible random brightness variations. All who saw it agreed that it was not acceptable. This was on an 8051-clone, so I ended up doing a "precision reload" of the timer so that the only variation in display timing was the 1 or 2 machine cycles of jitter in the interrupt latency (and zero cumulative error). -- Dave Tweed -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist