chrisma...@belgacom.net (Chris Mason) writes: > Back in 1967/8, a colourful customer on the patch to which I belonged > was running PCP on a 64K machine and it may have been a 360/40. Our > ace young salesman had been responsible for this! IIRC this was > considered the opposite of the leading edge but it seemed to work for > a while! > > While we did have a customer - a university - genuinely at the leading > edge with a 360/67, I worked at the crowded lower end among the > 360/30s running DOS/360. My first responsibility was assisting a > customer with the "free" time converting from a 1400 system to a > 360/30 with DOS/360.
the univ. had 709 running tape-to-tape ibsys with 1401 front-end for unit-record (reader->tape, tape->printer/punch, tapes manually transferred between 1401 drive and 709 driver). student jobs ran in under second elapsed time. univ. was sold a 360/67 for tss/360 to replace 709/1401 combo. As part of the transition, the 1401 was replaced with 64kbyte 360/30 ... which could run 1401 emulation and the front-end unit record 1401 MPIO application. I got a student job re-implementing MPIO on 360/30 (possibly as part of univ. preparation moving to 360) and got to design my own monitor, my own device drivers, interrupt handlers, scheduling, storage handling, etc. I eventually had a 2000 card (box of cards) assemble program ... with assembly option to either run stand-alone or under OS/360 PCP with five DCBs. The stand-alone version took approx. 30mins elapsed time to assemble (early os/360 PCP) while the OS/360 version took approx. an hour to assemble (each DCB macro assembly processing taking over five minutes elapsed time). I would get the datacenter all to myself on the weekend from 8am sat until 8am monday ... 48hrs w/o sleep made it little hard going to monday classes. The 709&360/30 was eventually replaced with 360/67 and since tss/360 wasn't yet read, it ran as 360/65 with os/360 ... initially the "same" student fortran jobs taking over a minute elapsed time. This was cut approx. in half with move to HASP and MFT. I was given responsibilty for the operating system ... and starting with OS/360 release 11 doing highly customized STAGE2 sysgens under the production operating system. I would carefully rework output of STAGE1 sysgen ... so it could run in the production operating system ... and that the allocation and move/copy steps carefully organized to optimize disk arm seek operation (location of datasets on disk as well as location of members within PDS). This gave me approx. three times additional speedup in 3step fortgclg for student jobs ... but still 13secs elapsed time (mostly job scheduler overhead) This is old post with some results that I presented at fall68 SHARE meeting in Atlantic City (univ. had also gotten copy of cp67 in Jan68 and let me play with it on the weekends, I rewrote large pieces cp67 during the spring and summer ... which is also included as part of the presentation) http://www.garlic.com/~lynn/94.html#18 later got univ. of waterloo's watfor (for student jobs), big speedup was eliminating job scheduler overhead for tray of batched student jobs ... the job scheduler overhead to start single-step watfor was still longer than the time it took watfor to process a whole tray of student jobs (typically around 2500 cards, 50-100 student jobs) ... but finally the 360/67 throughput was more than the 709. -- virtualization experience starting Jan1968, online at home since Mar1970 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN
