Many things have been extended. The CVT, e.g., has an extension (and even a prefix), as do many other system control blocks. The CKD architecture of DASD was extended in the early 1980s. The MVCL instruction has an extended variant, as does STCK and a host of other machine instructions. Users keep wanting more and more of everything. The proliferation of control block extensions was one of the many features of the new Hosed System Architecture whose pre-post-announcement was first pre-presented at the Chicago SHARE in August, 1991. E.g., this quaint new operating system had a CVT that had been enhanced so massively that its prefix had to have an extension and its extension had to have a prefix. This architecture was well received by that SHARE audience, but, sadly, less so by the buying public. Bill Fairchild
----- Original Message ----- From: "Norbert Friemel" <[email protected]> To: [email protected] Sent: Thursday, April 17, 2014 6:24:58 PM Subject: Re: Extended Addressibility (was: ZFS - Allocation Failure) On Thu, 17 Apr 2014 17:38:12 +0000, DASDBILL2 wrote: >Extended Addressability refers to an attribute of a data set that allows the >data set to contain more then 4GB of data. >Extended Format refers to each DASD block's having some extra bytes, called a >suffix, added to the end of each data block, and this can happen with data >sets that contain fewer than 4GB of data. >EAV stands for Extended Addressability Volumes and refers to an attribute of a >volume that allows it to have more than 65,536 (approximately) cylinders on >it, regardless of what kinds of data sets are stored there or how large they >are. > >These three buzzphrases all have the word "extended" in them, and two of them >also have the word "addressability" in them, but they are three different >concepts. > EATTR JCL/Data Class-Parameter: A data set with *extended* attributes (format 8 and 9 DSCBs) can reside in the *extended* address space (EAS) on an *extended* address volume (EAV). (EATTR was not available on MVS/eXtended Architecture ;-) Norbert Friemel ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
