On Sun, 21 Jun 1998 18:59:32 -0400  Andrew Brown wrote:

> i imagine (although i have no way of knowing) that some guy somewhere
> decided at one point that it would be cool if his compiler defined
> this symbol for him and added it as a hack.  and then everyone else
> saw it and knew that it was good.  who knows?  does anyone have some
> 20 year old at&t tapes lying around?

The oldest thing I can find lying around is a Genix archive for a
NatSemi 16032 machine, and cpp there defined "unix".  It's dated
'12/3/82' (which I assume is the 3rd of December, Americans getting
things backwards).  Not quite 20 years old, but I hope it will do :)

Simon.