I wasn't working then ๐, but I think that IMS/DB was developed then, as the bill of materials database. The question I have is when IMS/DC come along? The online documentation is unclear.
The Introduction to IMS says: IBM developed an online component to ICS/DL/I to support data communication access to the databases. The DL/I callable interface was expanded to the online component of the product to enable data communication transparency to the application programs. A message queue function was created to maintain the integrity of data communication messages and to provide for scheduling of the application programs. The online component to ICS/DL/I ultimately became the Data Communications (DC) function of IMS, which became the IMS Transaction Manager (IMS TM) in IMS Version 4. So *maybe* the original system just allowed some kind of communication access to the database, but not a full screen driven transaction server with a message queue like we know today. While we're on the subject of IMS/TM... Is it true that the MQ Series message queue was based on the IMS/TM message queue? Or is there no connection other than the function they provide. -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of rpinion865 Sent: Tuesday, July 25, 2023 1:09 PM To: [email protected] Subject: Re: [EXT] Ars Technica: The IBM mainframe: How it runs and why it survives I'm probably wrong. But I thought IMS was developed for NASA during the Gemini and Apollo time frame. Sent with Proton Mail secure email. ------- Original Message ------- On Tuesday, July 25th, 2023 at 2:05 PM, Schmitt, Michael <[email protected]> wrote: > No, I donโt know of an IMS/TM + DB2 system. > > But then the CICS systems I work with are also not using DB2. They use VSAM! > > And even for IMS/DB, my gut feel is there are a lot more CICS + IMS/DB > installations than IMS/TM + IMS/DB. > > > Also, CICS is from ~1966, IMS/DC (later renamed to IMS/TM in IMS Version 4) > must have been much later than that, but I can't find the date. > > Reason I think I it is much later (late 70's? early 80's?) is because, as I > understand it, the reason CICS was designed the way it is was because at the > time, the OS it ran on wasn't so great at multitasking. Or maybe didn't do > multitasking at all. But IMS/DC was designed at a time when the OS was good > at preemptive multitasking between tasks and jobs. Was this MVS? > > > -----Original Message----- > From: IBM Mainframe Discussion List [email protected] On Behalf Of > David Spiegel > > Sent: Tuesday, July 25, 2023 12:38 PM > To: [email protected] > Subject: Re: [EXT] Ars Technica: The IBM mainframe: How it runs and why it > survives > > Hi Michael, > I have yet to see a site running IMS/DC and not run IMS/DB. > Have you actually seen this? > > BTW, the article had more than one technical error. For example, a JCL > Step name with 9 characters. > > Regards, > David > > On 2023-07-25 13:16, Schmitt, Michael wrote: > > > The Ars Technica article was discussing CICS as an application server. I > > was comparing CICS as an application server to IMS/TM as an application > > server. The DBMS is a different issue; there's no reason why IMS/TM must be > > used with IMS/DB. You can use IMS/TM with DB2. > > > > The point I was trying to make was that CICS was designed as a cooperative > > multitasking system that reproduces all of the OS functions in itself. > > IMS/TM (originally IMS/DC) was designed to use the OS to do OS things and > > does none of that in itself, so it is much simpler. > > > > -----Original Message----- > > From: IBM Mainframe Discussion List [email protected] On Behalf Of > > David Spiegel > > Sent: Tuesday, July 25, 2023 11:48 AM > > To: [email protected] > > Subject: Re: [EXT] Ars Technica: The IBM mainframe: How it runs and why it > > survives > > > > Hi Michael, > > You said: "...CICS is to IMS as Windows 3.1 is to Windows 10. ..." > > You're comparing apples and oranges. > > (CICS has no native Database portion.) > > BTW, a lot of the banks, insurance companies etc. are running CICS+DB2. > > The majority of IMS users need it to support 40+ year old application > > systems. > > Which one is the real dinosaur? (Hint: It's not CICS) > > > > Regards, > > David > > > > On 2023-07-25 10:37, Schmitt, Michael wrote: > > > > > So CICS is no longer doing cooperative multitasking within each AOR, and > > > thus requiring CICS versions of OS commands to prevent wait states from > > > freezing the entire AOR? A CICS program can do direct GETMAINs, LOADS, > > > abends, rather than use CICS commands? CICS no longer requires special > > > versions of tools (e.g. debugger, abend dump management) and instead can > > > use the same tools as batch programs? A CICS programmer no longer needs > > > to learn a long list of CICS commands and EXEC CICS syntax? A CICS region > > > no longer contains the storage from all of the transactions currently > > > running and is now only one transaction in the region at a time? CICS > > > transactions can no longer stomp on each other's memory? > > > > > > Great, I did not know that. > > > > > > IMS/TM uses the operating system for multitasking. There are no IMS/TM > > > specific tools. An IMS/TM programmer only needs to know two commands, one > > > to get a message and another to send it. IMS transaction abends look > > > (almost) exactly like a batch abend. IMS programs have no restrictions on > > > OS facilities. An IMS program can even do an STIMER (WAIT) without > > > affecting any other transaction processing. Because, it uses the OS to do > > > preemptive multitasking, like a modern operating system. > > > > > > -----Original Message----- > > > From: IBM Mainframe Discussion List [email protected] On Behalf Of > > > Crawford Robert C (Contractor) > > > Sent: Tuesday, July 25, 2023 8:14 AM > > > To: [email protected] > > > Subject: Re: [EXT] Ars Technica: The IBM mainframe: How it runs and why > > > it survives > > > > > > Sorry, I worked in a shop that had both and I can tell you CICS is way > > > more flexible, modern and performed better. > > > > > > I will give you this: IMS is a great piece of 90's technology. > > > > > > Robert Crawford > > > Abstract Evolutions LLC > > > (210) 913-3822 > > > > > > -----Original Message----- > > > From: IBM Mainframe Discussion List [email protected] On Behalf Of > > > Schmitt, Michael > > > Sent: Monday, July 24, 2023 11:43 AM > > > To: [email protected] > > > Subject: [EXT] Ars Technica: The IBM mainframe: How it runs and why it > > > survives > > > > > > Ars Technica published a deep-dive explainer of modern IBM mainframes: > > > > > > https://arstechnica.com/information-technology/2023/07/the-ibm-mainframe-how-it-runs-and-why-it-survives/ > > > > > > Iโd quibble with the application server topic that talks about CICS with > > > no mention of IMS/TM. CICS is to IMS as Windows 3.1 is to Windows 10. ๐ > > > > > > ---------------------------------------------------------------------- > > > For IBM-MAIN subscribe / signoff / archive access instructions, send > > > email to [email protected] with the message: INFO IBM-MAIN > > > > > > ---------------------------------------------------------------------- > > > For IBM-MAIN subscribe / signoff / archive access instructions, > > > send email to [email protected] with the message: INFO IBM-MAIN > > > > > > ---------------------------------------------------------------------- > > > For IBM-MAIN subscribe / signoff / archive access instructions, > > > send email to [email protected] with the message: INFO IBM-MAIN > > > ---------------------------------------------------------------------- > > > For IBM-MAIN subscribe / signoff / archive access instructions, > > > send email to [email protected] with the message: INFO IBM-MAIN > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to [email protected] with the message: INFO IBM-MAIN > > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > > > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
