Path: csiph.com!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Lynn Wheeler Newsgroups: alt.folklore.computers Subject: Re: Emulating vintage computers Date: Thu, 26 Sep 2024 08:39:41 -1000 Organization: Wheeler&Wheeler Lines: 71 Message-ID: <87tte2s1hu.fsf@localhost> References: MIME-Version: 1.0 Content-Type: text/plain Injection-Date: Thu, 26 Sep 2024 20:39:43 +0200 (CEST) Injection-Info: dont-email.me; posting-host="5881e439a9cbfb9a2b608b1bc8d1e218"; logging-data="355827"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/q2CKuXXKuLspHnT3xMota1Pry2cONj/Y=" User-Agent: Gnus/5.13 (Gnus v5.13) Cancel-Lock: sha1:8pTvaqclKIWmtIoLYcgv6GfrP4g= sha1:0cNSbMJ7XNk9ESoTxw6BOSRHflY= Xref: csiph.com alt.folklore.computers:227046 Lars Poulsen writes: > Like I have been impressed that Hercules on a similar platform runs > OS/360 MVT with a performance like a 1960s mainframe. also in the wake of the Future System implosion, I also got con'ed by Endicott into helping with 138/148 ECPS microcode (148 was about 600KIPs 370)... told that there was 6kbytes and needed to indentify the highest executed 6kbytes of kernel 370 execution segments. 370 instruction simulation ran avg ten native instructions per 370 instruction (about the same as some of the 80s i86 370 emulators) ... and dropping kernel 370 instructions into microcode about on byte-for-byte ... running ten times faster. old archived (a.f.c.) post with top 370 6kbytes accounting for 79.55% of kernel execution: https://www.garlic.com/~lynn/94.html#21 little over decade ago was asked to track down the IBM decision to add virtual memory to all 370s, found staff member to executive making the decision. Basically MVT storage management was so bad that regions sizes had to be specified four times larger than used ... as a result typical 1mbyte 370/165 only ran four concurrent regions, insufficient to keep system busy and justified. Mapping MVT to 16mbyte virtual memory would allow concurrent regions to be increased by factor of four times (caped at 15 for the 4mbit storage protect keys) with little or no paging (aka VS2/SVS), sort of like running MVT in a CP/67 16mbyte virtual machine. Lat 80s got approval for HA/6000 project, originally for NYTimes to move their newspaper system (ATEX) off DEC VAXCluster to RS/6000. I rename it HA/CMP when I start doing numeric/scientific cluster scale-up with the national labs and commercial cluster scale-up with RDBMS vendors (Oracle, Sybase, Informix, and Ingres that had RDBMS VAXCluster support in the same source base with Unix). IBM had been marketing a fault tolerant system as S/88 and the S/88 product administrator started taking us around to their customers ... and also got me to write a section for the corporate continuous availability strategy document (section got pulled when both Rochester (AS/400) and POK (mainframe) complained that they couldn't meet the requirements. Early Jan1992, in meeting with Oracle CEO, AWD/Hester told Ellison that we would have 16-system clusters by mid-92 and 128-system clusters by ye-92 ... however by end of Jan1992, cluster scale-up had been transferred for announce as IBM Supercomputer and we were told we couldn't work on anything with more than four processors (we leave IBM a few months later). Complaints from the other IBM groups likely contributed to the decision. (benchmarks are number of program iterations compared to reference platform, not actual instruction count) 1993: eight processor ES/9000-982 : 408MIPS, 51MIPS/processor 1993: RS6000/990 : 126MIPS; 16-system: 2016MIPs, 128-system: 16,128MIPS trivia: in the later half of the 90s, the i86 processor chip vendors do a hardware layer that translates i86 instructions into RISC micro-ops for execution. 1999 single IBM PowerPC 440 hits 1,000MIPS 1999 single Pentium3 (translation to RISC micro-ops for execution) hits 2,054MIPS (twice PowerPC 440) 2003 single Pentium4 processor 9.7BIPS (9,700MIPS) 2010 E5-2600 XEON server blade, two chip, 16 processor, aggregate 500BIPS (31BIPS/processor) The 2010-era mainframe was 80 processor z196 rated at 50BIPS aggregate (625MIPS/processor), 1/10th XEON server blade -- virtualization experience starting Jan1968, online at home since Mar1970