Jay Maynard wrote:
On Tue, Dec 20, 2005 at 09:08:49PM -0800, Edward E. Jaffe wrote:
Jay Maynard wrote:
ALS5, z9 and other architectural enhancements
What the heck is ALS5? AFAIK, we aren't even at ALS3 yet (unless you use
that designation to loosely refer to the z/Architecture requirement for
z/OS 1.6)!
Roger wrote that. I believe ALS3 refers to z/Architecture; ALS4 refers to
the z990 level, and ALS5 refers to the z9 level. I (and he) could easily be
wrong; if so, we'd appreciate a correction.
Sounds like "artistic license" to me. The addition of a new hardware
generation with new features does not create an architectural level set.
An architectural level set occurs when the operating system folks draw a
"line in the sand" saying their system will not run on any machine that
does not have features "x, y, and z". The first architectural level set
(now known as ALS1) occurred with OS/390 V2R10. The features it required
can be found in this list:
http://www.ibm.com/servers/s390/os390/plug.html
The second architectural level set (now known as ALS2) was not
established by technical people but rather by edict from the "geniuses"
in marketing. That's why it backfired and angered so many customers. It
occurred with z/OS V1R1. The additional features it required can be
found in this list:
http://www.ibm.com/servers/s390/os390/plug1.html
The next "line in the sand" was the requirement by z/OS V1R6 to run in
z/Architecture mode. Some have called this ALS3. All z/OS releases will
still run on the original "freeway" (z900) machines and there have been
no level sets since.
The next level set probably won't occur for years. When it does
eventually arrive, most of us will probably consider it to be ALS4 --
even if IBM abandons the "level set" terminology in favor of something new.
Again, a new hardware generation with new features is not an
architectural level set. Rather, an architectural level set is a list of
hardware features required by the operating system. Or, put another way,
a program can determine which hardware features are guaranteed to be
available by testing the level of the operating system in the CVT.
--
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| Edward E. Jaffe | |
| Mgr, Research & Development | [EMAIL PROTECTED] |
| Phoenix Software International | Tel: (310) 338-0400 x318 |
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| Los Angeles, CA 90045 | http://www.phoenixsoftware.com |
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