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Re: 'smttter IBMdroids

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re:
http://www.garlic.com/~lynn/2011k.html#82 'smttter IBMdroids
http://www.garlic.com/~lynn/2011k.html#84 'smttter IBMdroids
http://www.garlic.com/~lynn/2011k.html#86 'smttter IBMdroids

3033 being a q&d effort ... get out something in the 370
market place after the failure of Future System 
http://www.garlic.com/~lynn/submain.html#futuresys

because the killing off of 370 efforts during Future System is credited
with giving the clone processor vendors a market foothold. This
was going on in parallel with the 370xa & 3081 effort ... which
was also something of a Q&D hurry up effort ... but taking
much longer ... discussed in some detail in this reference:
http://www.jfsowa.com/computer/memo125.htm

3033 was starting to see lots of competition from endicott's
mid-range 4341 ... old email
http://www.garlic.com/~lynn/lhwemail.html#4341

clusters (loosely-coupled multiprocessing) of 4341s were cheaper, had
higher aggregate throughput, had more aggregate I/O, had more aggregate
memory, and required significantly less physical resources than 3033. At
one point the mid-range 4341 competition so bothered POK (responsible
for high-end 3033) that the head of POK slipped through manufacturing
allocation that cut the corporate allocation to Endicott of a critical
component for 4341 manufacturing in half.

some large customers were starting to have orders of 4341s in multiples
of hundreds and placing them out in departmental supply & conference
rooms (didn't require all the datacenter physical planning required for
3033) ... sort of the leading edge of the distributed computing wave.
Internally, the proliferation of distributed 4341s into departmental
areas was starting to make corporate conference rooms a scarce resource.

By the time of the 3033, MVS was becoming increasingly bloated in lots
of different wasy. The maximum amount of 370 real memory that could be
addressed was 16mbytes. Even in a 3033MP configuration the maximum
amount of 370 real memory was still limited to 16mbytes.

The MVS real-storage footprint bloat was becoming a throughput
bottleneck (pushing the 16mbyte limitation wall) for single 3033
processor ... and even much more so in a 3033MP two-processor
configuration (which was also still limited to 16mbyte).

In a real hack to get around the restriction ... a 3033 design was
created that allowed for 26 bit address lines (64mbyts) even though real
and virtual addressing was still limited to 24bits. The 370 page table
entry was 16bits, with 12bit real (4kbyte) page number, two defined
function bits and two undefined bits. The hack involved prepending the
two undefined bits to the 12bit real page number for 14bit real 4k page
number (or 64mbyte addressing). Lots of MVS addressing and operation was
limited to below the 16mbyte line ... but application virtual pages
could reside above the 16mbyte line ... each application virtual address
space was still limited to 16mbytes ... but with lots of different
virtual address spaces ... some amount of the virtual pages could reside
above the 16mbyte (real) address line (and with the magic of the hacked
page table entry, 24bit virtual addresses could be turned into 26bit
real addresses). This 3033 >16mbyte hack somewhat alleviated the bloated
MVS real-storage bottleneck ... there continued to be a "below the
(16mbyte) line" real storage constraint for many MVS things.

Even after 370/xa, mvs/xa and the introduction of 31bit addressing on
3081 ... MVS design point still had a "below the (16mbyte) line" storage
constaint (things that had to reside <16mbyte real storage). Even today
with hundreds of gigabytes of real storage, 64bit addressing ... there
are still reverences to MVS having a "below the (16mbyte) line"
constaint.

Normal 360 & 370 I/O operations (also) only allow for 24bit real
addressing. However, there was an extra feature added to 370 channel I/O
program that allowed for a storage address to be specified in 32bit full
word. This was taken advantage of in the 3033 >16mbyte hack to allow
specifying 26bit real storage operation for doing data transfers (like
paging virtual pages between real storage and disk). 

Part of the "below the (16mbyte) line" constraint was some operations on
virtual pages required it to be below the 16mbyte line. If virtual page
was above the line, then it had to be brought "below the line". Their
original design was to use the I/O system to write the virtual page to
disk (from its "above the line" location) and read it back in "below the
line). I provided them with a simple hack of fiddling pagetable entry
values and then do a MVCL 4k copy from one virtual address to another
... which happened to be from a real storage location above the line to
a real storage location below the line. 

Misc. past posts mentioning above/below the line hacks:
http://www.garlic.com/~lynn/2000d.html#82 "all-out" vs less aggressive designs (was: Re: 36 to 32 bit transition)
http://www.garlic.com/~lynn/2004e.html#41 Infiniband - practicalities for small clusters
http://www.garlic.com/~lynn/2004f.html#38 Infiniband - practicalities for small clusters
http://www.garlic.com/~lynn/2004k.html#44 Wars against bad things
http://www.garlic.com/~lynn/2005.html#34 increasing addressable memory via paged memory?
http://www.garlic.com/~lynn/2005p.html#19 address space
http://www.garlic.com/~lynn/2005q.html#30 HASP/ASP JES/JES2/JES3
http://www.garlic.com/~lynn/2005u.html#44 POWER6 on zSeries?
http://www.garlic.com/~lynn/2006.html#13 VM maclib reference
http://www.garlic.com/~lynn/2006l.html#2 virtual memory
http://www.garlic.com/~lynn/2006m.html#27 Old Hashing Routine
http://www.garlic.com/~lynn/2006w.html#23 Multiple mappings
http://www.garlic.com/~lynn/2007b.html#34 Just another example of mainframe costs
http://www.garlic.com/~lynn/2007g.html#59 IBM to the PCM market(the sky is falling!!!the sky is falling!!)
http://www.garlic.com/~lynn/2007r.html#56 CSA 'above the bar'
http://www.garlic.com/~lynn/2008f.html#12 Fantasy-Land_Hierarchal_NUMA_Memory-Model_on_Vertical
http://www.garlic.com/~lynn/2009g.html#71 308x Processors - was "Mainframe articles"
http://www.garlic.com/~lynn/2009g.html#74 308x Processors - was "Mainframe articles"
http://www.garlic.com/~lynn/2009l.html#67 ACP, One of the Oldest Open Source Apps
http://www.garlic.com/~lynn/2010.html#84 locate mode, was Happy DEC-10 Day
http://www.garlic.com/~lynn/2010.html#86 locate mode, was Happy DEC-10 Day
http://www.garlic.com/~lynn/2010b.html#87 "The Naked Mainframe" (Forbes Security Article)
http://www.garlic.com/~lynn/2010d.html#74 Adventure - Or Colossal Cave Adventure
http://www.garlic.com/~lynn/2010g.html#36 16:32 far pointers in OpenWatcom C/C++
http://www.garlic.com/~lynn/2010l.html#6 Z/OS 31bit or 64bit

-- 
virtualization experience starting Jan1968, online at home since Mar1970

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'smttter IBMdroids Robert Myers <rbmyersusa@gmail.com> - 2011-08-31 22:15 -0400
  Re: 'smttter IBMdroids Robert Myers <rbmyersusa@gmail.com> - 2011-08-31 22:20 -0400
    Re: 'smttter IBMdroids Anne & Lynn Wheeler <lynn@garlic.com> - 2011-08-31 22:31 -0400
      Re: 'smttter IBMdroids Robert Myers <rbmyersusa@gmail.com> - 2011-09-01 07:30 -0700
  Re: 'smttter IBMdroids Quadibloc <jsavard@ecn.ab.ca> - 2011-09-01 09:48 -0700
    Re: 'smttter IBMdroids nmm1@cam.ac.uk - 2011-09-01 17:58 +0100
    Re: 'smttter IBMdroids Stephen Fuld <SFuld@alumni.cmu.edu.invalid> - 2011-09-01 10:58 -0700
      Re: 'smttter IBMdroids nmm1@cam.ac.uk - 2011-09-01 18:51 +0100
    Re: 'smttter IBMdroids Anne & Lynn Wheeler <lynn@garlic.com> - 2011-09-01 15:42 -0400
    Re: 'smttter IBMdroids Robert Wessel <robertwessel2@yahoo.com> - 2011-09-01 18:19 -0500
      Re: 'smttter IBMdroids Anne & Lynn Wheeler <lynn@garlic.com> - 2011-09-01 20:57 -0400
      Re: 'smttter IBMdroids nmm1@cam.ac.uk - 2011-09-02 09:17 +0100
      Re: 'smttter IBMdroids nmm1@cam.ac.uk - 2011-09-02 09:19 +0100
        Re: 'smttter IBMdroids Robert Wessel <robertwessel2@yahoo.com> - 2011-09-02 04:44 -0500
          Re: 'smttter IBMdroids nmm1@cam.ac.uk - 2011-09-02 11:39 +0100
            Re: 'smttter IBMdroids Robert Wessel <robertwessel2@yahoo.com> - 2011-09-02 11:14 -0500
        Re: 'smttter IBMdroids Robert Wessel <robertwessel2@yahoo.com> - 2011-09-02 04:47 -0500
          Re: 'smttter IBMdroids nmm1@cam.ac.uk - 2011-09-02 11:26 +0100
          Re: 'smttter IBMdroids Anne & Lynn Wheeler <lynn@garlic.com> - 2011-09-02 08:48 -0400
          Re: 'smttter IBMdroids Anne & Lynn Wheeler <lynn@garlic.com> - 2011-09-02 09:29 -0400
  Re: 'smttter IBMdroids Del Cecchi <delcecchi@gmail.com> - 2011-09-01 17:15 -0500
    Re: 'smttter IBMdroids Robert Myers <rbmyersusa@gmail.com> - 2011-09-02 10:10 -0700
      Re: innovation from Armonk, was 'smttter IBMdroids John Levine <johnl@iecc.com> - 2011-09-02 21:21 +0000
        Re: innovation from Armonk, was 'smttter IBMdroids nmm1@cam.ac.uk - 2011-09-02 21:56 +0100
        Re: innovation from Armonk, was 'smttter IBMdroids Anne & Lynn Wheeler <lynn@garlic.com> - 2011-09-02 17:49 -0400
      Re: 'smttter IBMdroids Del Cecchi <delcecchi@gmail.com> - 2011-09-02 18:04 -0500
        Re: 'smttter IBMdroids Thomas Womack <twomack@chiark.greenend.org.uk> - 2011-09-03 00:16 +0100
          Re: 'smttter IBMdroids Robert Myers <rbmyersusa@gmail.com> - 2011-09-03 14:25 -0400
            Re: 'smttter IBMdroids Thomas Womack <twomack@chiark.greenend.org.uk> - 2011-09-03 20:09 +0100
        Re: 'smttter IBMdroids Robert Myers <rbmyersusa@gmail.com> - 2011-09-03 22:02 -0400
          Re: 'smttter IBMdroids Del Cecchi <delcecchi@gmail.com> - 2011-09-03 21:50 -0500
            Re: 'smttter IBMdroids Robert Myers <rbmyersusa@gmail.com> - 2011-09-03 23:52 -0400
      Re: 'smttter IBMdroids "Andy \"Krazy\" Glew" <andy@SPAM.comp-arch.net> - 2011-09-05 08:26 -0700
        Re: 'smttter IBMdroids Stephen Fuld <SFuld@alumni.cmu.edu.invalid> - 2011-09-05 11:14 -0700
          Re: 'smttter IBMdroids Terje Mathisen <"terje.mathisen at tmsw.no"> - 2011-09-05 22:05 +0200
          Re: 'smttter IBMdroids Robert Myers <rbmyersusa@gmail.com> - 2011-09-05 17:27 -0400
        Re: 'smttter IBMdroids Robert Myers <rbmyersusa@gmail.com> - 2011-09-05 17:16 -0400
          Re: 'smttter IBMdroids "Andy \"Krazy\" Glew" <andy@SPAM.comp-arch.net> - 2011-09-05 14:40 -0700
            Re: 'smttter IBMdroids Robert Myers <rbmyersusa@gmail.com> - 2011-09-05 15:45 -0700
        Re: 'smttter IBMdroids Del Cecchi <delcecchi@gmail.com> - 2011-09-06 21:47 -0500

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