DOS/360 and successors: Difference between revisions

In 1986 IBM released '''VSE/SP''' ("System Product") in conjunction with the announcement of the [[IBM 9370|9370]] processors. VSE/SP replaced SSX/VSE and bundled VSE with the most popular VSE program products such as VSE/AF, [[VTAM#ACF.2FVTAM|ACF/VTAM]], [[CICS]], and [[IBM POWER (software)|POWER/VS]].<ref>{{cite web|last=IBM Corporation|title=IBM VSE/SYSTEM PACKAGE (VSE/SP), VERSION 3 RELEASE 1.1 ENHANCED AND AVAILABLE|date=30 June 1987 |url=http://www-01.ibm.com/common/ssi/cgi-bin/ssialias?subtype=ca&infotype=an&appname=iSource&supplier=897&letternum=ENUS287-332&open&cm_mmc=5733-_-n-_-vrm_newsletter-_-10207_134134&cmibm_em=dm:0:12046832|access-date=June 1, 2011}}</ref> VSE/SP supported only 24-bit addresses, despite customer requests to provide an XA (31 bit) version.

VSE/ESA was a 31-bit DOS/VSE version, which was released in 1990 with support for up to 384&nbsp;MB of real storage. It provided up to twelve ''static partitions'' and allowed VSE/POWER and ACF/VTAM to be run in ''private address spaces''. It introduced a new feature called ''dynamic partitions'' which could allow up to 150 concurrent jobs, each in its own address space.<ref name=VSEESAAnnounce>{{cite web|last=IBM Corporation|title=IBM VSE/ENTERPRISE SYSTEMS ARCHITECTURE VERSION 1 RELEASE 1|date=5 September 1990 |url=http://www-01.ibm.com/common/ssi/cgi-bin/ssialias?infotype=an&subtype=ca&appname=Demonstration&htmlfid=897/ENUS290-513|access-date=May 31, 2012}}</ref> Version 1 could run in either ESA or 370 mode, with the ESA mode also supporting XA hardware with limitations. Version 2 (1995) only supported ESA mode with ESA hardware. Version 2 added support for [[multiprocessing]], through the new ''Turbo Dispatcher'', which permits different partitions to execute simultaneously on different processors. A partition can only run on one processor at a time, which mostly limits the multiprocessing to [[Computer multitasking|multitasking]]. Up to ten processors are theoretically supported ("tolerated"), but up to four are effectively utilized.<ref>{{cite web |title=VSE/ESA Version 2 Release 1 and VSE/ESA Languages -- PL/I, COBOL, LE Software Announcement | date=13 September 1994 |url=https://www.ibm.com/common/ssi/ShowDoc.wss?docURL=/common/ssi/rep_ca/9/897/ENUS294-519/index.html&lang=en-ZZ-ZZ |publisher=IBM}}</ref><ref>{{cite web |title=VSE/ESA Turbo Dispatcher Guide and Reference |url=https://ibmdocs.pocnet.net/SC33-6797-00.pdf }}</ref> Those limits remain in the last z/VSE.<ref>{{cite web |title=The z/VSE Turbo Dispatcher |url=https://www.ibm.com/docs/en/zvse/6.2?topic=SSB27H_6.2.0/fa2pl_zvse_turbo_dispatcher.htm |publisher=IBM}}</ref>