> Whats the best way to generate this? How have others handled it? I've used a 555 occassionally for just the backplane, and the ICM7211LP for a complete interface http://home.clear.net.nz/pages/joecolquitt/0sp505.html (sorry 'bout colours, needs fixing) -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist