I wish I could recall where I read his articles but it was Don Lancaster's articles. Colored makers, fan paper, cellophane tape, and the processor assembly card. That taught me how to think in reverse but the better I learned to think forward as an engineer help me understand how to think like an engineer. I still think that it would be useful but I'm sure there are new techniques that would be useful. --=20 Linux Home Automation Neil Cherry ncherry@linuxha.com http://www.linuxha.com/ Main site http://linuxha.blogspot.com/ My HA Blog Author of: Linux Smart Homes For Dummies --=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 .