Mainframes, how they work and what they do – M80

Mainframes, how they work and what they do – M80

what is a mainframe? how does it work? what does it do? what is the user interface of a mainframe?

This video shows the following:

1. what is a mainframe
2. what are they used for
3. what is the user intface today and how was it before
4. what are terminals
5. how programmers interact wit the mainframe with the example of IBM’s MVS 3.8
6. What mainframes cannot be used for.

This video is about 20 minutes long.

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50 Comments

  1. Pete Miller on July 30, 2022 at 12:41 am

    Do any other companies besides IBM currently make mainframes? Everything I see about mainframes is associated with IBM. Seems like they own the market.

  2. Alexander Sharpe on July 30, 2022 at 12:42 am

    Nice mainframe information, but a little dated regarding its capabilities:
    At the risk of being accused of advertising, I wish to dispel the beliefs that MVS (now z/OS) is a silo onto itself – with only a ‘green screen’ to interface with it. Please consider the following few examples:
    There is a file system (ZFS) under MVS/TSO, been there (OMVS) since 1994: https://www.ibm.com/support/knowledgecenter/zosbasics/com.ibm.zos.zconcepts/zconcepts_145.htm
    There are web interfaces into an IBM z/OS (MVS) mainframe system: https://www.youtube.com/watch?v=SdUsAI52QmY
    There are other modern interfaces to IBM mainframe development which use applications besides Host emulators, like [https://developer.ibm.com/mainframe/products/ibm-developer-for-z-systems-enterprise-edition/]
    And while the COBOL compiler may have started out half a century ago, the features of the current version of the compiler is ‘worlds apart’ from the initial version – keeping in touch with all of the modern mainframe features of the IBM Z15:[https://www.ibm.com/products/cobol-compiler-zos?mhsrc=ibmsearch_a&mhq=cobol%206.3]
    Plus there are vibrant open source applications which run within the z/OS environment, as well as the LINUX on IBM Z platform. The IBM Mainframe is alive and well!
    My opinions are my own (RS).

  3. Bruce Hewson on July 30, 2022 at 12:46 am

    "I accessed the MAINFRAME!" makes me smile. IBM happens to be the biggest player in the mainframe market. These days the zSeries boxes can run up to 60 partitions, and each partition can run an operating system. Usually big business will have at least 2 boxes in a datacenter so that work can continue to run even when one box gets powered down. One of those operating systems is Z/OS (latest name of MVS). Another is zVM. zVM is a Virtual Machine operating system, which by design, runs other virtual operating systems. Which can include thousands of Linux on Z instances. Moshix did not say that the MVS 3.8J system he was demonstrating was released in 1981. and that it is still usable. The modern MVS version (Z/OS) is far more advanced as it has evolved over the last 40 years to stay on top of all the requirements of business and fashion. In the latest iteration you can now run Linux applications within containers directly in Z/OS. I have been working with MVS since 1980 and have watched it grow continuously over those years. For me, working with MAINFRAMEs is still a marvelous and exciting industry to work in.

  4. Jeetender Kakkar on July 30, 2022 at 12:46 am

    1000

  5. 1,000,000 likes on July 30, 2022 at 12:47 am

    What do you know about a 9672 server? Or a 2084? How much is one and do you want to buy one?

  6. George's Channel (GPatsos) on July 30, 2022 at 12:47 am

    Great video! Always wanted to know the difference between a mainframe, supercomputers and personal computers!

  7. Vits Admin on July 30, 2022 at 12:48 am

    COBOL run in any computers depending on your compiler PC, Windows, UNIX, AS400 and Mainframe it access RDMS, VSAM, Flat Files Text, It can Link other object ASM, C, etc to perform SQL, and Communication such as TCPIP etc, this is the reason why it is unstoppable. In addition it is easy to read and structured English like self documentation line of codes not spaghetti type of codes other almost unreadable. Well we have so many object oriented languages and Web development tools we can use that as a front end it added more flexibility and nice presentation of the system from end to end process.

  8. k.d. katz on July 30, 2022 at 12:50 am

    Mainframe components are closely integrated. They don’t have miles of cable like in a server farm. The longer the wire, the slower the transfer of data.

  9. cmhacks on July 30, 2022 at 12:50 am

    WRKACTJOB CPUPCTLMT(10) INTERVAL(15) F19 F5 ( mainframe operator history Z ) xD

  10. Steve Ji on July 30, 2022 at 12:50 am

    Awesome video about mainframe! If I can name one to improve, may be the BGM. It feels a bit distracting.

  11. tpfmike1976 on July 30, 2022 at 12:51 am

    Think mainframe will ever go away..
    Heard cloud will take over everything

  12. Stefan Skoglund on July 30, 2022 at 12:55 am

    CATIA too

  13. Stefan Skoglund on July 30, 2022 at 12:56 am

    And then it is the small matte of CADAM. Most car and aircraft manufacturers ran all their CAD in a Sys/360 env (AT some time)

  14. Nalinkumar Murugesan on July 30, 2022 at 12:58 am

    If possible, Can you please elaborate about What is Mainframe modernization and what is migrated to cloud ? and how it helps?

  15. maraz666 on July 30, 2022 at 12:58 am

    Intro music is from Purple Motion – Satellite One: https://www.youtube.com/watch?v=_3B2kAxdV9Y

  16. Stefan Skoglund on July 30, 2022 at 12:59 am

    I Wonder i believe Princeton ran a Cray (running Crays version of UNIX) as a host for The researchers X Windows terminals

  17. Joseph Muller on July 30, 2022 at 1:02 am

    Can one use SQL on a COBOL program running on a mainframe?

  18. Bradley Gaddis on July 30, 2022 at 1:03 am

    WOW. What a trip. I had my first computer course on an RCA 301 in machine language in 1969, hands on push button octal to activate the card reader. Then onto IBM 360’s with Fortran, Assembler, COBOL, PL/1(my favorite), APL, JCL, ALGOL, etc. Compiler writing, operating systems, etc; with Norm Chomsky, Donald Knuth, Allen Turing, and other heavies as my references. I could program in my dreams while asleep and while awake at times a "Window" would open up and the correct code would assemble ,and yes they worked. In short, I love High Tech, Math, AI, etc.

  19. Tyrone Walker on July 30, 2022 at 1:05 am

    I had no idea that mainframes and supercomputers were two different machines!

  20. Roberto Lucena on July 30, 2022 at 1:06 am

    Yes good vídeo about the mainframe, I started in 1977, in a Road Construction Engineering Company, by side of Maracana Stadium in Rio de Janeiro, BR, with IBM /370, only punch cards and papers, with Fortran and Cobo. With 64 years I just move to the US, willing to work here, hey guys I’m available to work with Assembler, Cobol, CICS, DB2, Rexx, look for my Linkedin profile: linkedin.com/in/rmlucena.

  21. FORTRAN4ever on July 30, 2022 at 1:09 am

    [WARNING: LONG RANT!]
    When I started off as a computer programmer/analyst at a large Federal installation, the thought of doing serious "data processing" on a PC was a dream. I wrote large number crunching programs in FORTRAN (FORmula TRANslater) on a Sperry Univac 1100 series mainframe environment using the EXEC 8 OS. Projects had accounts where the division was charged computer time. An infinite loop in a program was an expensive mistake . Also, mass storage usage was also charge to the account. That account was real and deducted from the division’s budget.
    A few years later it was fun programming on a PC (debase Iii PLUS and my favorite Clipper, both in 3Gl’s) not worrying about being charged for "systems resources" which was pre-Windows. Years passed and sysrems I created n the Windows environment (in Power Builder, GUI development tool) quickly yielded to WEB based applications. Concurrently, I developed applications using an IBM proprietary language called Application System (a 4GL) on small IBM 4341 and 9370 named for 9+370) but it was in a VM OS enviromment. What was different writing applications in the GIU environment verses 3GL’s and 4GL’s were that the new versions of say FORTRAN which happened about every 15 years or so where new versions of PowerBuildet came out every year with a completely new interface. Anyway, except for Y2K compliance programming which I put a lot of sweat and tears into,I basically did maintenance programming until I retired in the early 2000’s

  22. swwei on July 30, 2022 at 1:09 am

    When I learned that the IBM had ported Linux OS to to their mainframes,
    I was sure that a mainframe is no difference from a micro as far as programming is concerned.
    Processing speed is what makes all the difference.

  23. DelphiProgrammer on July 30, 2022 at 1:10 am

    My Compaq-486 that I used in my office in 1994 had 16 MB of memory. It just barely handled Windows NT.

  24. Massimo M. on July 30, 2022 at 1:11 am

    when i will retire, i will buy a second hand mainframe and i will spend my life having fun with it.

  25. Daniel G on July 30, 2022 at 1:11 am

    Thanks !

  26. Rob Winchester on July 30, 2022 at 1:11 am

    terminal emulators (of various limitations) where around since at least the mid-ish 80s. connection options where seriously limited, usually due to cost, until the later 90s (and I can’t remember what got you into SNA from a PC anymore). I still miss setting up Rumba macros 🙂

  27. detaart on July 30, 2022 at 1:12 am

    Their main reason for (still) being is that governments, banks, etc bought into the ecosystem all of these years ago, and now it is simply not economically viable or even feasible to migrate away from it.
    Other than these organizations that still use them, "mainframe" computers are irrelevant and a relic of the past. A _very_ expensive relic of the past. Bill by the cycle … sheesh …
    They are supposed to be super reliable and whatnot, but … i think a modern distributed approach to things is more reliable in the end. A big Z series machine failed just last week at one of my customers. Infallible, they are not. Amazing hardware running an operating system from what seems like 100 years ago. Yet even amazing hardware can fail.

    I think the hardware design is amazing, but IBM as a company is just terrible. Everything they do must be so convoluted and complicated. They want to send you engineers and consultants for even the simplest of tasks. And then you have to pay for CPU time on the hardware that you bought yourself!
    Even downloading software from them from PAO is an exercise in pure frustration.

    I love these machines … from afar … but i wouldn’t be sad to see them go.

  28. Ron Hansard on July 30, 2022 at 1:13 am

    There is so much misinformation given in this presentation, that I wouldn’t recommend it to anyone.

  29. Shiunbird on July 30, 2022 at 1:16 am

    Very good!

  30. zomgneedaname on July 30, 2022 at 1:18 am

    one day when all the colbol programmers die out, we’ll be looking at this video to figure out how to maintain the global financial system

  31. Robert Saler on July 30, 2022 at 1:20 am

    you make mainframes sound sexy . . .

  32. Richard Conte on July 30, 2022 at 1:20 am

    I miss text terminals

  33. yours cutely on July 30, 2022 at 1:20 am

    Is there any career or future in this field: Mainframes?

  34. Chill Bro on July 30, 2022 at 1:20 am

    hahahaha very entertaining beginning! Wow this is what i was looking for a couple of days ago. I was looking specifically for z/OS and from a programmer’s perspective.

  35. Roger Suhr on July 30, 2022 at 1:21 am

    Today all that equipment has been reduced to 3-4 refrigerator sized cabinets

  36. Noman Baluchi on July 30, 2022 at 1:21 am

    Can you please explain me the kinds of terminal???

  37. Stephen Muga on July 30, 2022 at 1:21 am

    If mainframes are meant to process large numbers of business records and/or business transactions, then why not just use web and database servers? MySql is pretty fast, so working with, say, 500 million records won’t be an issue. I just don’t get why mainframes still exist. Will research further.

  38. Carly on July 30, 2022 at 1:22 am

    i had to use that same marist university mainframe for my assembler language class

  39. gcolombelli on July 30, 2022 at 1:26 am

    I wonder how people even begin programming on mainframes nowadays. The hardware and software seem so completely alien and access to development tools/environment probably isn’t as simple as any other mainstream language.

  40. misium on July 30, 2022 at 1:27 am

    Technically speaking, what is the actual difference between a data center or cluster and a mainframe? The cpu processing power, the I/O hardware, performance? What actually is it that makes mainframe a mainframe?
    You highlighted the major differences between the mainframe OS and an ordinary OS, so how does a mainframe with Linux compare to a Linux server or even workstation? You get all the "modern" tools, like filesystems, grep, C, C++, maybe even python, right?
    Any particular example, imaginary or not of the kind of workload that a Linux mainframe can do but a powerful "normal", server with dozens of cores and hundreds of GB memory, does not?
    edit:whitespace

  41. Tou on July 30, 2022 at 1:28 am

    So, why not just get an Exadata instead? I feel like the only reason why Mainframes are still are around because no one knows how or doesn’t want to migrate them to a modern architecture.

  42. Scara Faggio on July 30, 2022 at 1:29 am

    The meaning of the word "mainframe" has evolved over the years. Now it typically just means "big".

    If you look carefully at the photo of the IBM 3090 at the beginning of the video you can see the actual processor is that "X" shaped box closest to the camera. Most of the other boxes are storage devices. But if you open up the covers and look inside the 3090 you will see that the electronics is packaged in multiple "frames". So if an engineer is looking for a particular component he might be directed to find it in "frame A" or "frame "B" etc. This packaging technique was used back through s/370 and s/360 and earlier generations (and by other manufacturers too). A big s/360 processor might have a lot of these frames spread across multiple physical boxes. So the term "mainframe" began by meaning "The Main Frame" … probably the one with most of the actual central processor logic. I/O devices were connected using secondary processors called "channels" and each channel occupied its own "frame". Then memory would be in other frames. Etc.

    An analogy with a desktop PC might be to label each add-on PCI card as frame A,B,C etc then the memory might be frame D,E,F, and the main-frame would be the actual CPU chip. The motherboard would be a rats nest of cables under the floor connecting the frames together. Okay this is a dodgy analogy, but these old machines used a lot of components which had to be packaged somehow.

  43. Jan Kro on July 30, 2022 at 1:29 am

    I studied Cobol in the 70’s on a Wang and decided to stick to hardware instead software 🙃

  44. Reinaldo Puig on July 30, 2022 at 1:30 am

    Hello, good video, it reminded me of the 80-90s that I was working with Mainframe with silly terminals with green letters, but with a lot of productivity, we had more than 200 users and those terminals spread throughout the city. I assure the skeptics that no current PC can process millions of transactions per minute. The truth is that IBM made one of the best computers for those times and even today, this type of architecture was born forever.
    I would like to work in that environment again, as I am a COBOL developer and I have known that many companies are looking for a specialist in this language, but I cannot find any reference,
    Could you recommend me some. Thank you.

  45. Tommy Mairo on July 30, 2022 at 1:30 am

    Curious about whether the OS in the mainframe compiles those batch jobs into native machine code or runs an interpreter to execute them like scripts?

  46. 1,000,000 likes on July 30, 2022 at 1:32 am

    What’s the difference of a mainframe, server, and a mainframe server?

  47. taith2 on July 30, 2022 at 1:34 am

    I think the closest feel for an average user to a ceasing mainframe are USSD codes

  48. David White on July 30, 2022 at 1:35 am

    It won’t rust, won’t bust, won’t collect dust, and it’s a base for trust!

    I love how he shows the archaic 3090-200! I cut my teeth on 3090-600J/MVS-XA and MVS ESA 4.2. Currently working with z/OS 2.3.x.

    There is nothing that works like a mainframe system. The tenets for this architecture are Speed/Availability/Stability/Security. To use the system no real GUI is necessary, as we have the most versatile and configurable environment for a workstation, TSO with ISPF/PDF. Customer front-ends are generally run under CICS and a database backend.

    You can deliver a bale of bricks in an hour by using one Ox, or in 2 months using 50,000 chickens.

  49. Aleks Vitek on July 30, 2022 at 1:40 am

    Terrific explanation, thanks

  50. Vaibhav Joshi on July 30, 2022 at 1:40 am

    What 120 programmers do or do they upload data?

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