Vitaliy maksimov.org> writes: > Found it: > > http://www.circuitcellar.com/pastissues/articles/Stewart91/text.htm Nice find Vitalyi. I was thinking more along the lines of using an audio spectrum analyzer chip's outputs as cepstral inputs to a pic. I will look into your link when I have time. Peter -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist