The following message is a courtesy copy of an article that has been posted to bit.listserv.ibm-main,alt.folklore.computers as well.
[EMAIL PROTECTED] (Shmuel Metz , Seymour J.) writes: > No. The original design of OS/360 was that all programs were > subroutines. A program written to be called as a jobstep task could > also be called via LINK or ATTACH from another program. It was never > designed for programs to assume that they were jobstep tasks, although > IBM may have written code[1] that assumed that. some number of univ. developed their own student job "monitors" (predating availability of watfor). we had 709 running fortran monitor for student jobs ... running tape-to-tape ... tapes were physical moved back and forth between 709 and 1401 ... with the 1401 handling front-end unit record processing. student job elapsed time was on the order of a second. moving to 360/65 with os360 and hasp ... minium elapsed time for 3step (student) fortran compile, link-edit and go ... was on the order of 30seconds ... effectively all of it (constantly re)executing job scheduler. various univ one-step job monitors attempted to "attach" compile, link-edit, and go for student jobs (eliminating job scheduler overhead). i had done some custom optimization with very careful reorganization of stage-II sysgen output cards ... in order to very carefully physically place files and PDS members on disk ... for optimal arm seek operation. this had improved 3step (effecitvely job scheduler) from 30seconds to about 13seconds (for typical student fortran job). part of old presentation at aug68 SHARE meeting in boston discussing very careful os360 stage-2 sysgen optimization ... in addition to separate activity rewritting large amounts of cp67 virtual machine kernel http://www.garlic.com/~lynn/94.htmL#18 CP/67 & OS MFT14 of course when watfor became available ... it eclipsed a lot of the work on one-step job monitors. ---------------------------------------------------------------------- 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
