Phil (and the rest of you) You may find this interesting:-
http://vm.marist.edu/~vmshare/browse.cgi?fn=HISTORY&ft=MEMO&args=cp67#hit note that you won't find VMSHARE articles via google. The site isn't indexed anywhere else. Dave > -----Original Message----- > From: cctalk <cctalk-boun...@classiccmp.org> On Behalf Of Phil Budne via > cctalk > Sent: 29 May 2020 23:39 > To: cctalk@classiccmp.org > Subject: Re: history is hard > > > From: Noel > > > From: Jon Elson > > > > > As far as I know, there was no VM/360. There WAS VM/370, which was > out > > > in the early 1970's > > > > CP/67, which was a semi-product, and ran only on 360/67's, was > > basically the same functionality as VM/370. (I get the impression that > > the code was descended from CP/67, but I can't absolutely confirm that > > - although see Varian, below.) > > In the last decade worked with another contractor (whose name I have > thankfully forgotten: after he removed a purely symbolic layer of indirection > in my code, and when I explained why it was there (to allow hardware > operations to be specified in a platform independent way, to make it easy to > move the system to new hardware) tritely > replied: "if wishes were fishes") who made it ABUNDANTLY clear to me that > VM/370 was significantly different from CP-67. Aw rats, found his > name: Dave Tuttle. > > FWIW, on VM/370 being a reimplementation: > https://en.wikipedia.org/wiki/CP/CMS says: > > In 1972, IBM announced the addition of virtual memory to the > S/370 series, along with the VM/370 operating system, a > reimplementation of CP/CMS for the S/370. > > also > IBM reimplemented CP/CMS as its VM/370 product line, released > in 1972 when virtual memory was added to the S/370 > series. VM/370's successors (such as z/VM) remain in wide use > today. (It is important to note that IBM reimplemented CP-67, > as it had CP-40, and did not simply rename and repackage > it. VM coexisted with CP/CMS and its successors for many > years. It is thus appropriate to view CP/CMS as an independent > OS, distinct from the VM family.) > > and > hypervisor: a mechanism for paravirtualization. This term was > coined in IBM's reimplementation of CP-67 as VM/370. > > > One version of CP/67 provided a /370 virtual machine; it was used > > extensively by the MVS development team. CP/67 was also brought up on > > /370 hardware. > > To amplify: My introduction to "how wonderful VMs are" were was when I > worked at BU (after leaving DEC) and told story of how CP or VM was ported > to new hardware by running a second level VM (on a production > system) that simulated the new hardware, and then VM for the new > hardware could be booted in a THIRD level VM. (As a DECie I was dubious > about such things, tho they could have helped me debug TOPS-20 monitors > in daylight, as opposed to waiting to take BUCS20 standalone at night). > > Maybe this is it, on pdf page 30, document page 28 of Varian's paper: > http://www.leeandmelindavarian.com/Melinda/25paper.pdf > > Alain Auroux did most of the actual coding and testing for the > bootstrapping, but Rip Parmelee, Bob Adair, and Charlie Salisbury > were also heavily involved in working out the design. When Auroux > started, Cambridge was running a 360/67, not a S/370, and that 67 > was a production system, so he had to avoid destabilizing it. > ?Vanilla? CP-67 systems created System/360 virtual machines, but > they did not virtualize the 360/67; that is, they did not allow a > guest to create its own virtual storage. Auroux?s first step was > to modify CP-67 to create virtual 360/67s, which used 4K pages and > 1M segments. Once he had convinced the Cambridge Operations > Manager torun that as the production system, he could then proceed > to develop a CP-67 that virtualized theSystem/370 architecture. > > The System/370 relocation architecture was different from the > 360/67 architecture; it allowed both 2K and 4K pages and both 64K > and 1M segments. So, Auroux modified his modified CP-67 to > support 64K segments and the new System/370 instructions. He ran > that system second-level, so he could run a virtual S/370 > third-level. He developed a prototype ?CP-370? in that > third-level virtual machine. Then, to test this CP-370?s > virtualization of System/370 virtual memory, he had to run it both > third- and fourth-level, with a couple of CMS machines running > fifth-level. He remembers doing much of his testing from home at > night using an ?old, slow, noisy teletype?. His prototype CP-370 > had been debugged in simulation by the end of 1970. Late in > January, 1971, just before Auroux was to return to France, he > and Bob Adair and Rip Parmelee took copy of his system to Endicott > so that they could test it on a prototype 370/145 with relocation > hardware. It IPLed the first time > > My recall was that they booted (sorry, IPL'ed) on the real hardware before > any of IBM's "real" operating systems did. > > This may be it, in footnote 91, which spans across two pages(!), starting > BEFORE the previous paragraph: > > An IBM newsletter announced the awards given for the > virtualization of System/370 on the 360/67 (?Cambridge Men > Modified CP-67, Providing Tool for Developers?, IBM News,vol. 9, > no. 15, August, 1972, p. 1.): > > CAMBRIDGE, MASS.: The work of four men at the Scientific Center > here begun almost two years ago had an important role in the > development of the operating systems announced this month. The > four have received Outstanding ContributionAwards for their > work. Two of the men, Dr. Richard Parmelee and Alain Auroux, > are now with IBM France in Paris and Grenoble. Charles > Salisbury and Robert Adair remain with the Scientific Center > staff. > > The four extended and enhanced CP-67, the control program that > provided virtual machine capability on a Model 67. Their > enhancement of the program gave IBM developers access to virtual > 370s on a Model 67 as well as a version of CP-67 which would run > on System/370. The central modifications to the program made by > the IBMers were: support of the new dynamic address translation > facility, additional control registers, and some of the new 370 > instructions and features. It became a tool for many IBMers > writing the new virtual machine and virtual memory operating > systems. Their extensions provided a means of testing 370 > programs on Model 67 hardware even before 370 hardware was > available internally. > > ?Moving CP-67 from a 360 base to a 370 base meant that the > CP/CMS Development Group working on VM/370 had something to > start running on their 145?, explains Dr. William Timlake, > Scientific Center manager. ?The people in SDD writing VS code > also had something to use in developing virtual memory > software.? In mid-1970, an SDD advanced system programming team > headed by Russ Hamrick asked the four to assist in developing a > virtual machine system for the 145. ?We obtained the > architectural specifications of the 370 advanced functions and > together developed the initial code?, notes Adair. > > Two prototype systems resulted: one to provide virtual 370s on > the 67 (required for testing, since the advanced hardware was not > available), the other to provide virtual machines on a > System/370. > > A critical test of the modified program came whenAuroux > travelled to Endicott to try the program on a prototype Model > 145. ?That was one of high points?, recalls Salisbury. ?Auroux > loaded the disk pack onto theengineering model, a computer that > had never run an advanced function operating system, and the > system ran successfully. It demonstrated that software could > be developed on a virtual machine for hardware not yet produced.? > After that, use of the modified CP-67 programs spread to several > locations where development activity was underway. > > More of the bloody history of how IBM was dragged into time sharing is > outlined at: > > https://en.wikipedia.org/wiki/IBM_System/360_Model_67 > https://en.wikipedia.org/wiki/IBM_CP-40 > (as always veracity is dubious at best). > > Yes, history is hard! > > I think it's hard to get across how alien a concept VM was to those like me > who came from small(er), interactive computers. IBM systems were large, > and expensive, were great at doing bulk disk I/O (rigidly laid out on disk), but > terrible (or at least uninterested) in handling anything as interactive as > character at a time terminals. > > VMs on commodity hardware didn't gain traction for maybe a quarter > century after the original "CP/CMS" work.