Doug's list is slightly off: adb v7-v10 sdb v8-v10 sdb may actually have been in V7; I'm quite sure it was present in 32/V. But it's not in the V7 manual. adb and sdb were certainly working fine when I arrived in 1127, but they still used ptrace because nobody wanted to touch the code. I used adb quite often (still would were it available in modern worlds!), so I cared enough to take it over, restructuring it quite a bit to make it easier to retarget for different instruction sets and byte orders, and of course to use /proc. I also made some trivial, compatible changes to how numbers were read and printed to conform to Rob's Rule (of which I am also a fan) that what a program presents as output it should also accept as input. sdb I wasn't as fond of, but I did want to get rid of ptrace, so I tinkered it just enough to accomplish that. I do remember clearly celebrating the death of ptrace by removing ptrace(2) from the copy of the V8 manual in the UNIX Room. It took up two pages, and they happened to be facing pages, so I glued them together. I wish it was as easy for others to have such satisfaction these days. Norman Wilson Toronto ON