David A Freeman ([log in to unmask]) asked a good question:
 
: What is MPE/ix?
 
I'm sure you'll get lots of answers in notes and in the mail, but let me
give you the "official" HP answer.  From a marketing perspective, there are
three different MPE operating systems:
 
1)      MPE/V (used on "classic" 16-bit HP 3000s)
2)      MPE XL (used on PA-RISC HP 3000s) and
3)      MPE/iX (also used on PA-RISC HP 3000s).
 
Technically speaking, it would probably be more correct to say that there are
only two MPE operating systems; HP decided to rename MPE XL to MPE/iX as of
version 4.0 - so from a technical perspective it would be more correct to say
that these are, in fact, two different versions of the same thing.  But from a
marketing perspective, HP wanted to call attention to the fact that, as of 4.0,
HP's strategic direction for the 3000 became bringing open systems
functionality
to MPE.  Hence the renaming...
 
: Is it MPE with a unix like shell?
 
Almost.  As of 4.5, HP equipped MPE with a second set of intrinsic-like
interfaces, compliant with the IEEE POSIX standards (1003.1 and 1003.2).  For
performance reasons, these weren't implemented as a layer of software on top of
MPE, but rather side-by-side with the intrinsics (the idea being that it should
take no longer to access a file via the "open" interfaces than it does via the
traditional proprietary interfaces).  MPE includes a shell program, (not
unlike the UNIX kshell), and the ability to create directories, case-sensitive
filenames, etc. etc.
 
The POSIX environment on MPE was further enhanced on version 5.0 of MPE/iX.
5.0 also comes bundled with a computer based training program that explains all
of this in detail.
 
: Is it
: required for newer 3000 systems?
 
MPE/iX 5.0 is a platform release, which means it has been shipped to all MPE
customers that have current support contracts.  Most models of the HP 3000
can run either the older 4.0 software, or the newer 4.5 and 5.0 releases.
A few of the newest models of the HP 3000 (e.g. the 9x9KS servers) require 5.0.
HP 3000 users tend to be a conservative lot, and with good reason.  HP's own
marketing research shows that the 3000 is the preferred platform for mission
critical applications and "heads down" OLTP - so customers update to new
software slowly and with great caution.  It should be no surprise, then, that
most HP 3000 customers are still using 4.0 today.
 
Today, the oldest version of MPE/iX that HP supports is 4.0, so technically if
you are still running on MPE XL (pre 4.0), you are running obsolete software.
Support for 4.0 will lapse sometime around February of '96, so we anticipate
most customers should be updated to 5.0 before that date.
 
Hope that helps.