All, would anybody have an e-mail address for Dick Haight? I am still trying to narrow done the date when pipes were added to Unix, so far between June 72 and January 73. I have this quote from Dick: "I happened to have been visiting the research crew the day they implemented pipes. It was clear to everyone practically minutes after the system came up with pipes working that it was a wonderful thing. Nobody would ever go back and give that up if they could help it." so he might be able to provide a smaller date range than what I have at present. Cheers, Warren