On 25Aug21:0804-0700, Michael Stein wrote: > On Thu, Jul 10, 2025 at 07:23:19PM -0500, Mark S Waterbury wrote: > > Does anyone recall any details about "EXCHANGE" -- software originally > > developed by UCLA for OS/360 MVT, and later ported to MVS. > > > > This allowed message passing between regions or address spaces, using > > a concept where one job would put a message up on a "shelf" (in CSE in > > MVS), and the target job could periodically check that (named) "shelf" > > for any messages. > > > I can barely find any mention of "The EXCHANGE" from ULCA on the interweb. > > That was a long time ago. I found a reference to the programming manual > for the Exchange: > > Braden, R., and Feigin, S., "Programmer's Guide to the Exchange". > Technical Report TR5, Office of Academic Computing, UCLA, > March 1972. > > The related department name at UCLA was called Campus Computing Network > back in 1972 (UCLA/CCN) but later changed it's name to the obove Office > of Academic Computing (UCLA/OAC). > > I found some references but no copies on the web: > > https://scholar.google.com/scholar?q=Braden%2C+R.+T.+and+Feigin%2C+S.+C.%2C+%22Programmers%27+Guide+to+the+Exchange%2C%22+CCN+Technical+Report+%23TR5%2C+Campus+Computing+Network%2C+UCLA%2C+Los+Angeles%2C+Calif.%2C+March+1972%2C+52+pp.%5D%5D > > https://www.computerhistory.org/collections/catalog/102687847/ > > The original version of that would say Campus Computing Network but > was still TR5. > > That was many years ago, and both authors are deceased. > > The Exchange only ran on MVT. MVT had only real memory and thus one > address space and did not implement storage fetch protection. At least > some usage of EXCH depended on that. EXCH was implemented as a small > type 1 SVC linked into the MVT nucleus. > > It predated TSO at UCLA/CCN and originally didn't support TSO sessions > at all. Later when TSO support was added to Exchange it had to interact > with TSO to cause swapins. I suspect that only one end of the Exchange > could be a TSO session. > > > It was loosely based on the idea of EXCP, with an EXCH macro for > > assembler users, and also had a PL/1 CALL level interface (what today > > we call an "API".) > > The origin of Exchange was before my time so I don't know about the EXCP > reference or Exchange origins. When I showed up at UCLA it was > already established in use and use was expanding. > > The Exchange was used internally at UCLA/CCN on the 360/91 for many > purposes as well as used by the ARPA control program. (This was the > original ARPAnet before TCP/IP, UCLA/CCN was one of the early hosts on > the original ARPA research network.) > > Braden email on 360/91 as host > https://www.sophiehonerkamp.com/othersite/isoc-internet-history/2012/may/msg00095.html > https://en.wikipedia.org/wiki/Interface_Message_Processor > > TCP/IP Implementations and vendors guide > https://apps.dtic.mil/sti/citations/ADA165418 > https://apps.dtic.mil/sti/pdfs/ADA165418.pdf > Feburary 1986 > pdf page 75 IBM VM > pdf page 77 IBM VM WISCNET > pdf page 80 UCLA MVS --> UCLA ACP > UCLA ARPANET control program > > https://en.wikipedia.org/wiki/File:Interface_Message_Processor_Front_Panel.jpg > > ARPAnet logical map 1977 > shows UCLA 360/91 connected > https://en.wikipedia.org/wiki/File:Arpanet_logical_map,_march_1977_PDP-10.png > > > Does anyone recall if this software was ever made available on any of the > > SHARE tapes, e.g. for the OS/360 MVT or MVS projects, etc.? Or elsewhere? > > I don't believe that the Exchange was ever on a SHARE tape but I might > be wrong. It was referenced in the ARPA control program documentation > but I don't believe it was distributed with the ACP. It may have > been distributed on a direct basis to some sites a long time ago. > > The change from MVT to MVS at UCLA/OAC was a major event. Many local > system changes made to MVT were not carried over to MVS including > Exchange, however the UCLA ACP was continued and several paths were > started to support it. > > UCLA/IPC (part of UCLA/Mail) was one, another was using ACF/VTAM. > The ACP wound up using the VTAM choice, UCLA/Mail was started as a test > program for UCLA/IPC (the previous internal, non-network, local only > email system was dropped and this replaced it). > > > Lionel B Dyck > > Try this https://www.cbttape.org/uclamail/uclamail.htm > > Right. That has a minimum system level of MVS/SP1.3.0. I have some > mods I have yet to distribute which allow assembling and running it on > a base MVS 3.8 system. This involves assembling with ASMG instead of > ASMH as well changes to replace several features of MVS/SP1.3.0 which > were added after MVS 3.8.
I cannot help regarding Exchange. But I was supporting the final version of the ACP as part of a turnkey TCP/IP for MVS service offered by Network Solutions from 1984-1988. I sent my 2400' reel of the official UCLA distribution (which included a legal document certifying its legitimacy) to the Hercules folks since I figured they were the most likely project to be able and willing to make it available to all interested. -- <not cent from sell> May the LORD God bless you exceedingly abundantly! Dave_Craig______________________________________________ "So the universe is not quite as you thought it was. You'd better rearrange your beliefs, then. Because you certainly can't rearrange the universe." __--from_Nightfall_by_Asimov/Silverberg_________________ ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
