That makes sense if it's '73. That would be
the Ritchie front end and
v5/v6 syntax as I remember=20
Here:
http://publications.csail.mit.edu/lcs/specpub.php?id=717
is the TR describing it (well, this report covers one by him for the Honeywell
6000 series, but IIRC it's the same compiler). I didn't read the whole thing
slowly, but glancing quickly at it, it sounds like it's possible a 'from
scratch' thing?
Noel