Apart from the fact the focal plane distance and distortion due to other lens elements in the existing iPhone lens package screw up this idea...the builder also picked a Canon EF lens, which by default, unpowered is left at full aperture. Canon EF lenses stop down on command through the serial port in the EF interface. If this guy had actually managed to interface the EF mount electronically to the iPhone's camera subsystem...well, that would be pretty cool.

A better choice would have been to use an older Nikon (or M42, or K-mount) which has a manual aperture ring on the rear.

My guess is this setup would yield very narrow field of view (due to the smaller sensor and longer focal length), a fair amount of distortion and probably a lack of infinity focus (due to the distance extended from the existing lens groups--I would assume this is like using an extension tube).

No, they don't. The Nortel Meridian series have always run a proprietary "OS" developed by BNR/Nortel. Offboard management was handled by a PC running Windows (Meridian Administration Tools, now OTM). The primary PBX software load (called X11, now CS1K Rel4) continues to be developed, it now runs over top of VxWorks. The management tools also continue to be developed, still on Windows.

What you're probably referring to is a Norstar (the smaller PBX) NAM (Norstar Applications Module) which is an outboard voicemail and ACD system that attaches to a Norstar key system PBX. It is not part of the PBX for call processing.

The NAM does run OS/2 but has been discontinued quite a while ago. It was replaced by the CallPilot 100/150 which runs VxWorks IIRC.