re:
http://www.garlic.com/~lynn/2023e.html#68 The IBM System/360 Revolution
http://www.garlic.com/~lynn/2023e.html#69 The IBM System/360 Revolution
and
http://www.garlic.com/~lynn/2023e.html#65 PDP-6 Architecture, was ISA
last year posts related to 50th anniv of VM/370 (after decision to add virtual memory to all 370s)
https://www.linkedin.com/pulse/zvm-50th-lynn-wheeler/ https://www.linkedin.com/pulse/zvm-50th-part-2-lynn-wheeler/ https://www.linkedin.com/pulse/zvm-50th-part-3-lynn-wheeler/ https://www.linkedin.com/pulse/zvm-50th-part-4-lynn-wheeler/ https://www.linkedin.com/pulse/zvm-50th-part-5-lynn-wheeler/ https://www.linkedin.com/pulse/zvm-50th-part-6-lynn-wheeler/ https://www.linkedin.com/pulse/zvm-50th-part-7-lynn-wheeler/ https://www.linkedin.com/pulse/zvm-50-part-8-lynn-wheeler/
I've mentiioned various times asked to tract down decision to add
virtual memory to all 370s. Found staff to executive making
decision. Basically MVT storage management was so bad that region sizes frequently had to be specified four times larger than used. As a result
typical 1mbyte 370/165 only ran four regions concurrently, insufficient
to keep processor busy and justified. Moving MVT to 16mbyte virtual
memory (similar to running MVT in CP67 16mbyte virtual machine) allowed
number of concurrently running regions to be increased by factor of four
with little or no paging. Archived 2011 afc post with pieces of email
exchange
http://www.garlic.com/~lynn/2011d.html#73
Science center had joint project with Endicott to enhance CP67 virtual
machine support to support 370 virtual memory architecture ... and then
modify CP67 to run with 370 virtual memory (instead of 360/67 virtual
memory). My CP67L ran on the real 360/67, CP67H ran in virtual 360/67 (supporting 370 virtual machines), CP67I ran in virtual 370 (extra layer
not running CP67H on real hardware was because Cambridge system also had professors, staff and students using the system, and wanted extra
security layer preventing unannounced virtual memory from leaking). This
was in regular use a year before before the 370 hardware (engineering
370/145) was operational with virtual memory support (and CP67I was used
for testing real hardware). Then three people from San Jose added 3330
and 2305 device support for "CP67SJ" (sometimes cp370) ... which was in production use on internal 370 machines long before (and after) VM/370 operational.
In the morph from CP67->VM370, lots of CP67 features were dropped and/or simplified. I then spent parts of 1974, adding CP67 (initially) into
VM/370 for CSC/VM (aka after joining IBM one of my hobbies was
production operating systems for internal datacenters). I would sometime
needle the MULTICS people on the 5th flr that at some point, I was
supporting more CSC/VM production internal systems than the total number
of MULTICS systems that ever existed (aka some of the MIT CTSS/7094
people went to 5th flr to do MULTICS, others went to the science center
on 4th flr and did internal network, virtual machine, invented)
science center posts
http://www.garlic.com/~lynn/subtopic.html#545tech
some recent posts mentioning CP67L, CP67H, CP67I, CP67SJ
http://www.garlic.com/~lynn/2023e.html#44 IBM 360/65 & 360/67 Multiprocessors
http://www.garlic.com/~lynn/2023d.html#98 IBM DASD, Virtual Memory
http://www.garlic.com/~lynn/2023.html#74 IBM 4341
http://www.garlic.com/~lynn/2023.html#71 IBM 4341
http://www.garlic.com/~lynn/2022h.html#22 370 virtual memory
http://www.garlic.com/~lynn/2022e.html#94 Enhanced Production Operating Systems
http://www.garlic.com/~lynn/2022e.html#80 IBM Quota
http://www.garlic.com/~lynn/2022d.html#59 CMS OS/360 Simulation
http://www.garlic.com/~lynn/2022.html#55 Precursor to current virtual machines and containers
http://www.garlic.com/~lynn/2022.html#12 Programming Skills
http://www.garlic.com/~lynn/2021k.html#23 MS/DOS for IBM/PC
http://www.garlic.com/~lynn/2021g.html#34 IBM Fan-fold cards
http://www.garlic.com/~lynn/2021g.html#6 IBM 370
http://www.garlic.com/~lynn/2021d.html#39 IBM 370/155
http://www.garlic.com/~lynn/2021c.html#5 Z/VM
--
virtualization experience starting Jan1968, online at home since Mar1970
--- MBSE BBS v1.0.8.4 (Linux-x86_64)
* Origin: Wheeler&Wheeler (3:633/280.2@fidonet)