Hi, many of you surely know it already, but for those who don't.. while this is not as powerful as LTspice or other professional programs, it's still very handy: http://www.falstad.com/circuit/ Cheers, Mario --=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 .