where did `partition' come from?

The sub-disks that one divide real disks into on UNIX systems are usually called `partitions' these days. But that's not what they were originally called on UNIX: - V7 hp(4) and rp(4) refer to `sections' and `pseudo-disks'. 32V hp(4) refers to `portions' and `pseudo-disks.' Later Research UNIX manuals, once Section 4 was being edited again, settled on `sections.' - System V Release 5.0 (the most recent system for which I have the device driver part of the manual) also refers just to `sections.' (So far as I can remember, this convergence was a coincidence; I think I'm the one who decided to use `sections' on the Research side, and I think I did so just because it was the more graceful of the historic cases, though my memory is not clear.) - 3BSD and 4.0BSD follow 32V; in 4.1BSD, the term `partition' appears as well. The System V preference for `section' lives on in the device naming scheme on System-V-derived, but the documentation even on those systems just says `partition' these days. It looks to me like `partition' came in from the Berkeley world. Does anyone on the list remember where it came from? Was the new term introduced on purpose, or did it just creep in in the way language usually changes? Norman Wilson Occasional pursuer of arcana