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Weekly t-shirt challenge: Mainframe Trivia take 2

  • 1.  Weekly t-shirt challenge: Mainframe Trivia take 2

    Posted Thu May 28, 2020 08:52 PM

    Mainframe Trivia - let's try again


    Well this has never happened before - no one entered last week's t-shirt challenge!  I asked for Mainframe Trivia and the only post was @Kathy Bazinet encouraging all of the mainframe musicians!  So since I can change the "rules" of this game whenever I want, I'm going to give Kathy a t-shirt just for being so nice!!

    So let's try this trivia thing again.  This community has a mix of experienced mainframers and newcomers just learning.  I know you have some interesting tidbits to share with each other!  This is your chance to talk about how Fred Brooks didn't want to lead the System 360 project but ended up making it hugely successful.  Or why don't you tell us about why Column 72 means continue to the next line?  Why do mainframes use EBCDIC instead of ASCII?  I'm sure you have more.  Bring it!



    The rules*:
    1.  Every Thursday, I'll start a new discussion thread titled Weekly Challenge.

    2.  This week, reply to the thread with your mainframe trivia.  

    3.  Vote for your favorite entries by clicking the "Recommend" button next to your favorites.

    4.  The following Thursday, I'll announce the winner and start the next week's thread.

    5.  The person submitting the item with the most votes will receive one of these Legends of Z t-shirts (or equivalent)!

    * The rules are not really rules.  This isn't a real contest or anything.  It's just something I feel like doing and having a fun excuse to share some cool t-shirts with you.  I hope you all have fun with it.  I am!

    Misty


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    Misty Decker
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  • 2.  RE: Weekly t-shirt challenge: Mainframe Trivia take 2

    Posted Fri May 29, 2020 05:49 AM
    Edited by William Downie Fri May 29, 2020 05:51 AM

    IEFBR14 is probably the most used program that doesn't do anything. If you're new to the Mainframe you'll soon be using it. The name of this program is derived from:

    IEF - IBM department that wrote it
    BR -  Assembler BRanch instruction
    14 -  Register 14

    So, all IEFBR14 does is a "BR 14". Well sort of.

    When I started out in Mainframes one of the old lads (was probably only 45) in the team told me when IBM originally shipped IEFBR14 a bug was found in it.

    Standard linkage is R14 contains address to return to and R15 contains the address of the called program. This meant, IEFBR14 returned a non-zero completion code (the value in R15).

    So, a second version was shipped that cleared R15 before doing the "BR R14", resulting in the completion code being 0.

    Whether or not this is true, I don't know. But, I find it funny that the smallest program in the world contained a bug.

    You can look at IEFBR14 using ISRDDN . After starting ISRDDN input "mem IEFBR14". This returns the module address in storage. Tab to the box and hit enter:

     BROWSE IEFBR14&PLPA&Start:00E92000&Size:00000008 Line 00000000 Col 001 080
    Command ===> Scroll ===> CSR
    ********************************* Top of Data **********************************
    +0 (00E92000) 1BFF07FE 00000000 * ...Ú.... *
    ******************************** Bottom of Data ********************************

    1BFF = SR 15,15 (sets completion code to zero)
    07FF = BR 14





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    William Downie
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  • 3.  RE: Weekly t-shirt challenge: Mainframe Trivia take 2

    Posted Thu June 04, 2020 08:47 PM

    I can confirm that the story about IEFBR14 is correct.

    I always thought it was hilarious too!

    I also know of at least one other PTF for IEFBR14 in addition to the one you reference about setting the RC.

    We had to ship an update to fix the copyright!  That's right, a routine that literally does nothing needed a copyright statement!



    ------------------------------
    Misty Decker
    Master the Mainframe

    www.linkedin.com/in/misty-decker/
    @MistyMVD on Twitter
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  • 4.  RE: Weekly t-shirt challenge: Mainframe Trivia take 2

    Posted Fri May 29, 2020 06:42 AM
    I don't know if this is really not widespread, but the 80 columns defaults from mainframe had somewhat "bleeded" on the personal computing as many personal computers had a screen size that emulates Size 2 (24x80) configuration. Even those that didn't had it by design, like the MSX 1 systems, tried to implement ways to emulate this via expansion cards. Even today, many Linux graphic terminals (like Konsole) starts with 24x80 by default thanks to this.


    ------------------------------
    Fábio Emilio Costa
    Performance Analyst
    SERPRO
    Sao Paulo
    +551121731676
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  • 5.  RE: Weekly t-shirt challenge: Mainframe Trivia take 2

    Posted Wed June 03, 2020 05:05 AM
    I love the concept of "Mainframe Legacy" you presented via the 80 column card!

    ------------------------------
    Kathy Bazinet
    North America z Sytems DevOps and Digital Transformation Technical Sales Manager
    IBM
    Hartford CT
    860-888-9921
    ------------------------------



  • 6.  RE: Weekly t-shirt challenge: Mainframe Trivia take 2

    Posted Thu June 04, 2020 04:32 AM
    And now Linus wants to change it...

    Anyway, it's amazing how many people still run ISPF in mode 2, although there are of course also people who've moved on to the other "standard" mode 3/4/5 screens. I myself use Tom Brennan's Vista TN3270 here at home, and on a full HD (1080x1920) screen use a 62x160 layout.  Most standard ISPF screens don't use all of the available space, but it's really great for the editor, (although many of my datasets are still FB(80)), and when you're browsing data, I've got about 2Gb of regression testing output producing 250Mb of SuperC output, not having to scroll them left-to-right is ever so convenient!

    I even used it at my last workplace, and many of my colleagues were envious of the amount of screen space it gave me!

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    Robert Prins
    Programmer/analyst-programmer
    Freelancer "between contracts"
    Vilnius
    +370 60549447
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  • 7.  RE: Weekly t-shirt challenge: Mainframe Trivia take 2

    Posted Thu June 04, 2020 06:50 AM

    I myself use a Model 5 terminal as much as I can

    But I can understand Linus idea on removing the terminal limits, although not necessarily agree
    Serpro
    Fabio Emilio Costa
    Analista
    Superintendência de Produtos e Serviços-Centro de Dados
    Diretoria de Operações
    (11)2173-1676
    (11) 94552-0688






  • 8.  RE: Weekly t-shirt challenge: Mainframe Trivia take 2

    Posted Fri May 29, 2020 05:37 PM

    Fred Brooks' single biggest decision.

    Systems available during the early 1960's were primarily built on 4, 6 or 7 (ASCII) bit bytes.

    Fred Brooks made the decision to change the IBM 360 series from a 6-bit byte to an 8-bit byte.

    IBM then introduced the System/360 eight-bit Extended Binary Coded Decimal Interchange Code (EBCDIC), an expansion of their six-bit binary-coded decimal (BCDIC).

    The modern standard of eight bits remains today.


    System/360 Model 65 operator's console, with register value lamps and toggle switches (middle of picture) and "emergency pull" switch (upper right).

    It's not System/360, but I decided to include an old Polaroid of myself working at a system console back-in-the-day!   Working on mainframes was and continues to be great fun!



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    Barbara Cullis
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  • 9.  RE: Weekly t-shirt challenge: Mainframe Trivia take 2

    Posted Tue June 02, 2020 11:15 AM

    Hello MTMers!

    I'm not sure whether this is trivia, or just obscure.  I remember when I attended school in Windsor, at UofW, (and before that, when we used to just come on campus and scam job cards off of unsuspecting clients).  We hoipoloi suffered in rooms stuffed with keypunch machines, and submitted our jobs on the outside terminal (massive cardreader and even more massive printer), or passed them through the window, if they required more resources.  Naturally, the faculty using the mainframe (at that time, the principal source of computing resource on campus) weren't about to maintain their treatises on card decks.  Also naturally, funds were not available for a 3270 in every office.  So we (er, they) all had dumb ascii terminals, which were connected to something  called Wylbur, which somehow managed to service hundreds of dumb terminals all over campus, and through magic, transform it into action on the 370.  We later learned that another program called Milten was part of this process.  It wasn't until I was long gone from there that I became aware of Wylbur's brother Orvyl (which we didn't use at UofW), which made the obvious connection among the three names fall into place.  I don't know if this is the Wright kind of material for trivia, but it is pretty trivial.

    Missing mainframes,

    Dave



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    Dave Peel
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  • 10.  RE: Weekly t-shirt challenge: Mainframe Trivia take 2

    Posted Wed June 03, 2020 04:58 AM
    Misty,

    I am so excited to win a T-Shirt!

    Thank you

    ------------------------------
    Kathy Bazinet
    North America z Sytems DevOps and Digital Transformation Technical Sales Manager
    IBM
    Hartford CT
    860-888-9921
    ------------------------------