Straight from a slowly fading memory... In the early '70 IBM released a new and improved CRJE called TSO, a TCAM application program. I believe it was part of IBM's "worst-ever" release, OS/MVT Release 19. TSO brought us Sub-Tasking and related macros ATTACH and DETACH using a newly expanded control block called TCB mapped by IKJTCB among many other IKJ's of TSO. With TSO also came a new and/or improved Checkpoint/Restart for batch jobs an TSO. TSO used it to roll a long-running TSO command of some user out to 3330 storage, then roll the EDIT in progress of anther user back into core to process his/her next input line received by TCAM for an open DCB owned by the TMP, the region control task (IKJEFT01). In other words, *all* TSO users shared *one* (1) MVT region of typically 200K+ core storage, say 1/2 to 1/4 of a S360/65. The same concept was integrated subsequently into OS/VS1 and was very useable, somewhat affordable and justifiable for those of us who previously "hogged that friggin keypunch all day long" (1974, S370/158 512K DRAM).
Happy holidays to all, Merry Christmas ! Andreas F. Geissbuehler AFG Consultants Inc. http://www.afgc-inc.com/ ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN