Both MULTICS and TSS had page formatted volumes and memory mapped files. TSS had legacy support for BSAM and QSAM, but Virtual Access Method (VAM) was the normal access method, including Virtual Partitioned Access Method (VPAM) and Virtual Indexed Partitioned Access Method (VIPAM).
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 עַם יִשְׂרָאֵל חַי נֵ֣צַח יִשְׂרָאֵ֔ל לֹ֥א יְשַׁקֵּ֖ר ________________________________________ From: IBM Mainframe Discussion List <[email protected]> on behalf of Michael Stein <[email protected]> Sent: Wednesday, August 6, 2025 7:26 PM To: [email protected] <[email protected]> Subject: Re: UNIT=VIO External Message: Use Caution On Mon, Aug 04, 2025 at 04:41:33PM +0000, Seymour J Metz wrote: > I always considered VIO a hack. what I really wanted was for IBM to > steal ideas from TSS and MULTICS. Not knowing TSS or MULTICS but starting with MVT without HASP I considered HASP and JES2 spool a hack. Well, catalog, DASDM, jobq, were all too slow and did too much I/O so I see why it was created. But now we still have JES2 but also faster catalogs, index VTOCs, and vastly more storage so it's hardly needed. SYSOUT datasets were real datasets and could be put on specific volumes if extra space was needed (2314s!). Later with MVS, VIO was really useful. I used to run IEHMOVE with some small modifications which allowed using VIO for it's work files resulting in a large speedup. ---------------------------------------------------------------------- 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
