[email protected] (Mike Beer) writes: > https://www-03.ibm.com/systems/z/os/zvse/about/history1970s.html
Endicott told me there was 6kbytes available for assist microcode ... I was to identify the highest used code paths in the vm370 kernel for replication in microcode. (standard 370 kernel instructions translated on about byte-for-byte basis) the low & mid-range 370 native (vertical) microcode emulated 370 on about 10:1 basis ... so instructions moved from 370 to native code got approx. 10:1 speedup. old post with times I did of vm370 kernel for selecting 6k bytes of code segments for dropping into "ECPS" microcode http://www.garlic.com/~lynn/94.html#21 6kbyte cutoff accounted for 79.55% of kernel execution ... gets a 10:1 speedup. At the same time there was VS1 handshaking that bypassed certain VS1 processes and left it to VM370 ... resulting in VS1 under VM370 ran faster than stand alone on the bare machine. Endicott then tried to get corporate approval to preinstall vm370 on every 138&148 shipped from the factory (sort of like LPARs today). However, this is in the period after Future System implosion and mad rush to get 370 products back into the IBM product pipeline. POK kicked off 3033 & 3081 in parallel and convinced corporate to kill the vm370 product, shutdown the vm370 development group and move all the people to POK to work on MVS/XA (or otherwise MVS/XA wouldn't be able to ship on schedule). Endicott managed to save the VM370 product mission ... but had to reconstitute a development group from scratch ... but wasn't able to convince corporate to allow vm370 to be preinstalled on every 138&148. Note since DOS/VS and VS/1 were single virtual address space (something like original VS2, SVS) ... E-architecture dropped the single virtual address table into microcode ... and there were new hardware instructions to add&remove the virtual->real address page mapping. VM370 always ran in 370 mode supporting multiple address spaces. 4341 caused lots of problems for POK ... it performed better than 3031 (erzats 158) and small cluster of 4341s outperformed 3033, cost much less than 3033, had smaller footprint and used much less environmentals. In 1979, I got con'ed into doing 4341 benchmarks for LLNL that was looking at getting 70 4341s for compute farm ... sort of the leading edge of the coming cluster supercomputing (and cloud megadatacenter) tsunami. It was so threatening to highend mainframes, at one point, head of POK got allocation of critical 4341 manufacturing component cut in half. The price, environmentals & footprint for 4300s & FBA disks had dropped so far, that corporations started ordering large hundreds at a time for placing out in departmental areas (inside IBM it resulted in conference rooms becoming scarce commodity) ... sort of the leading edge of the coming distributed computing tsunami. Boeblingen lab had done 370 115&125 ... which was a nine position memory bus for up to nine microprocessers ... for the 115, all microprocessors (controllers, 370 "cpu", etc) were the same but with different microcode loads. The 125 was identical to 115, but the microprocessor for the 370 "cpu" was 50% faster (than the other microprocessors). This design/implementation was so threatening to other 370 models, the got corporate to discipline Boeblingen. At the same time that Endicott con'ed me into working on ECPS microcode assist (for 138/148), I got con'ed into doing 125 design/implementation which would have up to five of the faster CPU processors all in the same machine (with four positions left for controllers). In same ways it was as threatening to Endicott 148 as 4341 clusters was threatening to 3033. In the escalation meetings by Endicott to kill five processor 125, I was expected to do the technical arguments for both sides (pro/con 148+ECPS and pro/con for 5-way 125) -- virtualization experience starting Jan1968, online at home since Mar1970 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
