>From http://planetmvs.com/hlasm/s390faq.html#als
What is an Architectural Level Set? [2006-01-01] 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. This entry was created from a post on the IBM-Main newsgroup by Ed Jaffe. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Charles Mills Sent: Wednesday, July 26, 2006 11:27 PM To: [email protected] Subject: List of instructions by architecture level? Is there a concise list somewhere of specific machine instructions available by architecture level? Is "architecture level" an unambiguous term? I'm looking at the levels as defined in the description of the C/C++ compiler ARCHITECTURE option. Charles Mills +1-707-291-0908 ==================== This email/fax message is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution of this email/fax is prohibited. If you are not the intended recipient, please destroy all paper and electronic copies of the original message. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
