The following, which I just sent to TUHS, might be of intererest to some here.
Noel
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So, a while back I mentioned that I'd done tweaked versions of 'cp',
'mv',
'chmod' etc for V6 which retained the original modified date of a file (when
the actual contents were not changed). I had some requests for those versions,
which I have finally got around to checking and uploading (along with 'mvall',
which for some reason V6 didn't have). I've added them to a couple of my V6
pages:
http://www.chiappa.net/~jnc/tech/V6Unix.html#mvall
http://www.chiappa.net/~jnc/tech/ImprovingV6.html#FileWrite
Note (per the page) that the latter group all require the smdate() system
call, which was commented out in 'vanilla' V6 (because using it confused the
backup system); the page gives instructions on how to turn it back on.