I thought I would quickly make a list of commands we have, commands that are missing, and out-of-the-ordinary commands. Below, if a command has no comment, it's a V1 command that we have. Notes follow. I have not tried to list the missing /etc and /usr/... commands yet. /bin ---- : V2 cmd, 0405 binary ar as V2 binary b missing bas bcd missing boot missing cal cat cc V2 binary chball ? no idea check chmod chown cmp cp date db dbppt missing dc df ds V2 binary dsw dtf missing du echo V2 cmd, 0405 binary ed exit V2 cmd, 0405 binary fc V2 binary find V2 binary form goto V2 cmd, 0405 binary hup missing if V2 cmd, 0405 binary lbppt missing ld V2 binary ln login V2 cmd, 0405 binary ls mail maki V2 binary mesg mkdir mkfs mount mv nm V2 binary od pr rew rkd missing rkf missing rkl missing rm rmdir roff sdate missing sh size V2 binary skip ? no idea sort stat strip V2 binary stty V2 cmd, 0405 binary su sum tap tm tty type un V2 binary wc who write /etc ---- as2 V2 binary getty V2 cmd, 0405 binary glob init msh suftab uids I have a quote from dmr somewhere (I can't find it), but to paraphrase: early UNIX was under a constant state of development. We would tidy up now and then, write a new manual, then get back to development. The 1st Edition UNIX manual is dated November 3, 1971. The 2nd Edition UNIX manual is dated June 12, 1972. 1st Edition (1e) only used 0405 a.out files. 2nd Edition (2e) only used 0407 a.out files. I would guess that the executables that we have from the s2 tape are from a snapshot halfway between 1e and 2e, and at that point in time the kernel could execute both varieties. This would explain why some V2 commands are 0405 style, and some are 0407 style. Despite the dates on the PDF commentary where we got the kernel source, the kernel has to be around 1e, not much later. The kernel only knows about 0405 a.out files, and is missing all of the system calls new to 2e: hog, kill, makdir (renamed from 1e mkdir), smdate and sync. So: kernel is around 1e, Nov 1971 or close; executables are somewhere between 1e and 2e, but before June 1972 as we have 0405 and 0407 ones. Cheers, Warren