Path: ...!news.nobody.at!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Lynn Wheeler Newsgroups: comp.arch Subject: Re: third system syndrome, interactive use, The Design of Design Date: Wed, 08 May 2024 07:58:52 -1000 Organization: Wheeler&Wheeler Lines: 66 Message-ID: <87jzk4kwwz.fsf@localhost> References: <18997836ff477aadd027459cf387218c@www.novabbs.org> MIME-Version: 1.0 Content-Type: text/plain Injection-Date: Wed, 08 May 2024 19:58:57 +0200 (CEST) Injection-Info: dont-email.me; posting-host="07bd44bef81c6c65548dd633e3ef2e28"; logging-data="121201"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+Cgzqf5Ieuu+0+deMsqrmoalTpNgvhO7g=" User-Agent: Gnus/5.13 (Gnus v5.13) Cancel-Lock: sha1:1KkoKdTA+QYut/MRDO4KLYj0mdE= sha1:MtVllsferNpusxiIylfVyN3M1RI= Bytes: 4649 John Levine writes: > According to MitchAlsup1 : >>> TSS was a disaster due to an extreme case of second system syndrome, >>> but Michigan's MTS and IBM skunkworks CP/67 worked great. >> >>TSS at CMU was extensively rewritten in assembly and became quite >>tolerable--hosting 30+ interactive jobs along with a background >>batch processing system. When I arrived in Sept 1975 it was quite >>unstable with up times less than 1 hour. 2 years later it would run >>for weeks at a time without going down. > > For reasons I do not want to try to guess, AT&T did the software > development for the 5ESS phone switches in a Unix system that sat on > top of TSS. After IBM cancelled TSS, AT&T continued to use it as some > sort of special order thing. At IBM there were only a handful of > programmers working on it, by that time all quite experienced, and I > hear that they also got rid of a lot of cruft and made it much faster > and more reliable. > > At the same time, IBM turned the skunkworks CP/67 into VM/370 with a > much larger staff, leading to predictable consequences. TSS/360 was decommitted and group reduced from 1100 to 20. Morph of TSS/360 to TSS/370 was much better (with only 20 people). Both Amdahl and IBM hardware field support claimed they wouldn't support 370 machines w/o industrial strength EREP. The effort to add industrial strength EREP to UNIX was many times the effort to do 370 port. They did a stripped down TSS/370 with just hardware layer and EREP (called SSUP) with UNIX built on top. IBM AIX/370 and Amdahl UTS were run in VM/370 virtual machines ... leveraging VM/370 industrial EREP. CP/40 was done on 360/40 with virtual memory hardware mods; it morphs into CP/67 when 360/67 standard with virtual memory became available. Group had 11 people (1/100th TSS/360). When I graduate and join IBM, one of my hobbies was enhanced production operating systems for internal datacenters. With the decision to add virtual memory to all 370s, it was decided to do VM/370 and some of the science center people move to the 3rd flr taking over the IBM Boston Programming Center for VM/370 group. The group was expanding to 200+ and outgrew the 3rd flr, moving to the vacant IBM SBS bldg out in Burlington Mall (of rt128). Note the morph of CP67->VM370 dropped and/or simplified a bunch of features (including multiprocessor support). In 1974, I started migrating a bunch of CP67 stuff to VM370 R2. I had also done automated benchmarking system and was the the 1st thing I migrated ... however, VM370 couldn't complete a full set of benchmarks w/o crashing ... so the next thing I had to migrate was the CP67 kernel synchronization & serialization function ... it order for VM370 to complete benchmark series. Then I started migrating a bunch of my enhancements. For some reason AT&T longlines got an early version of my production VM370 CSC/VM (before the multiprocessor support) ... and over the years moved it to latest IBM 370s and propogated around to other locations. Then comes the early 80s when next new IBM was 3081 ... which was originally a multiprocessor only machine. The IBM corporate marketing rep for AT&T tracks me down to ask for help with retrofitting multiprocessor support to old CSC/VM ... concern was that all those AT&T machines would migrate to the latest Amdahl single processor (which had about the same processing as aggregate of the 3081 two processor). -- virtualization experience starting Jan1968, online at home since Mar1970