James B. DiGriz wrote: I believe the prolific Mr. Lancaster wrote an RTL Cookbook. <http://en.wikipedia.org/wiki/Resistor-transistor-logic> Unfortunately I don't have a copy. jbdigriz -------------------------- I think I have a copy of that book at home in Pleasanton. I'll be flying up Saturday morning and will have a look in the book case. If so, I should be able to get some scans of the pertinent sections for you. Do you live in the Bay area? I know copies of it have shown up on eBay in last 18 months, usually going for less than $10. Billy