Sven Mascheck: With "original implementation (post 7th ed", I meant the undistributed BellLabs-internal further development of 7th, the first system ever to implement #!, leading to 8th ed, etc. (4BSD just incorporated this). Not System V or other relatives, though. ======= Can you cite a reference? I'm quite familiar with what went on inside the system that was later called 8th Edition, having been on the inside at Bell Labs starting in mid-1984. But that was after the original research group's general move to VAXes--they had no PDP-11s left by then, except a few LSI-11s running special-purpose systems rather than UNIX. In fact the VAX kernel they had adopted, I think sometime earlier that year, was derived from that of 4.1 BSD. (It diverged quite a bit from that start later, for which I am appreciably to blame, but that has nothing to do with #!). So if #! was implemented in an earlier kernel I don't know just what was done. I'd assumed it was no different; if I'm mistaken I'd love to see just how it really was. Alas, the person I know was on the spot and was likely to remember just what happened in what order can no longer answer questions ... Norman Wilson Toronto ON