Lots of OS/360 code can still be run unchanged. Some will take an ABEND S0C4 due to accessing unassigned storage; that problem shouldn't exist for code written for an OS/VS2 or MVS/SP system.
ISAM may be an issue for some code, as may BTAM and QTAM.. -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of Rupert Reynolds <rreyno...@cix.co.uk> Sent: Monday, December 16, 2019 3:47 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Backward compat--how far? Another question, purely out of interest: Can the old MVS/SP code still run unchanged? I reminisced with a friend about the day he whinged about a 64k code segment size on Intel micros and I out-whinged him with a 4k code CSECT :-) Can a modern z/OS installation still assemble, link and run the old stuff, such as the typical local utilities we all saw: MYPROG CSECT MYPROG RMODE ANY MYPROG AMODE 24 STM 14,12,12(13) USING ... If so, that's quite an achievement, both in the changes and the flexibility of the original design! Rupert ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
