The following message is a courtesy copy of an article that has been posted to bit.listserv.ibm-main,alt.folklore.computer as well.
[email protected] (R.S.) writes: > I don't believe! I know pure H2O is dielectric, but it is virtually > impossible to keep it so clean especially in contact with metal (I > assume the conductors were metallic). > So I think, the water had to be *isolated*. That's all. I saw some > study of cooling power generator conductors (22kV, ??kA). Tubes (skin > effect). The goal was to have the liquid circulation insulated. It is > feasible even assuming fill up. > > Regarding to "z11" water cooling: what's wrong with water cooling??? > Why should we be ashamed of water cooling? > Is it old-fashioned? Dino-like? > Really? Look at newest graphic cards and CPU in PC game high-end boxes. > They almost require liquid cooling. Liquid cooling means hi-tech > nowadays. "The most sophisticated" (sales pitch quotation) rack > solutions are water-cooled. re: http://www.garlic.com/~lynn/2009b.html#46 Z11 - Water cooling? there is old folklore of the 3081 TCM modules ... with closed system liquid cooling, heat exchange, and liquid on the outboard side to handle all the heat. one of the stories is that there was thermal sensors ... that would kill the power (to keep from melting) ... but no flow sensors on the outboard cooling side. a customer lost flow on the outboard flow side ... but by the time the thermal sensors tripped the power, it was too late ... there was so much heat on the inboard side ... that they lost the TCMs. After that, customer sites were retrofitted with flow sensors on the outboard side of the heat exchange (that would kill power, before the heat had started to build up enough to trip the thermal sensors). some TCM URL references http://www-03.ibm.com/ibm/history/exhibits/attic2/attic2_015.html http://domino.watson.ibm.com/tchjr/journalindex.nsf/c469af92ea9eceac85256bd50048567c/5b94a637584c972785256bfa0067f507?OpenDocument http://ibmcollectables.com/gallery/view_album.php?set_albumName=album122 http://en.wikipedia.org/wiki/IBM_3081 http://www.vm.ibm.com/devpages/LUNSFORD/rdl_prof.html recent post mentioning 4341s being used to test 3081 TCMs: http://www.garlic.com/~lynn/2009b.html#22 Evil weather one of the issues with TCMs was that field engineers could no longer do "bootstrap" diagnostics that started with scoping. approach in 3081 was a "service processor" that had probes into all the TCMs ... and the "service processor" was "scopable" (field engineers could diagnose/replace the service processor ... and then use the service processor to diagnose the rest of the machine). with the increase in requirements and sophistication of "service processor", for the 3090, it was initially decided to go with 4331 running a highly modified version of vm370 release 6, and all the screens/menus done in CMS IOS3270. By the time 3090 shipped, the 4331 had been replaced by a pair of 4361s (redundant machines as alternative to having to diagnose the machine in the field) ... still running highly modified version of vm370 release 6 (and all the screens done in CMS IOS3270). misc past posts mentioning TCMs http://www.garlic.com/~lynn/2000b.html#36 How to learn assembler language for OS/390 ? http://www.garlic.com/~lynn/2000b.html#37 How to learn assembler language for OS/390 ? http://www.garlic.com/~lynn/2000b.html#38 How to learn assembler language for OS/390 ? http://www.garlic.com/~lynn/2000d.html#61 "all-out" vs less aggressive designs (was: Re: 36 to 32 bit transition) http://www.garlic.com/~lynn/2001k.html#7 hot chips and nuclear reactors http://www.garlic.com/~lynn/2002b.html#3 Microcode? (& index searching) http://www.garlic.com/~lynn/2002b.html#5 Microcode? (& index searching) http://www.garlic.com/~lynn/2002d.html#13 IBM Mainframe at home http://www.garlic.com/~lynn/2002e.html#20 What goes into a 3090? http://www.garlic.com/~lynn/2002l.html#10 What is microcode? http://www.garlic.com/~lynn/2004n.html#15 360 longevity, was RISCs too close to hardware? http://www.garlic.com/~lynn/2004n.html#22 Shipwrecks http://www.garlic.com/~lynn/2004p.html#35 IBM 3614 and 3624 ATM's http://www.garlic.com/~lynn/2004p.html#36 IBM 3614 and 3624 ATM's http://www.garlic.com/~lynn/2004p.html#41 IBM 3614 and 3624 ATM's http://www.garlic.com/~lynn/2005b.html#51 History of performance counters http://www.garlic.com/~lynn/2005h.html#13 Today's mainframe--anything to new? http://www.garlic.com/~lynn/2006r.html#36 REAL memory column in SDSF http://www.garlic.com/~lynn/2007g.html#23 The Perfect Computer - 36 bits? http://www.garlic.com/~lynn/2007g.html#29 The Perfect Computer - 36 bits? http://www.garlic.com/~lynn/2007h.html#9 21st Century ISA goals? http://www.garlic.com/~lynn/2007t.html#77 T3 Sues IBM To Break its Mainframe Monopoly http://www.garlic.com/~lynn/2008d.html#52 Throwaway cores http://www.garlic.com/~lynn/2008h.html#80 Microsoft versus Digital Equipment Corporation -- 40+yrs virtualization experience (since Jan68), online at home since Mar70 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
