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Questions tagged [mainframe]

Mainframe generally refers to the z/Architecture family of IBM computers which traces its ancestry back to the System 360 introduced by IBM in 1965. The most recent z/Architecture model is the z14 introduced in the summer of 2017. The operating system used by these machines can be z/OS, z/VM, z/VSE, z/Linux, and z/TPF.

Mainframe generally refers to the z/Architecture family of IBM computers which traces its ancestry back to the System/360 introduced by IBM in 1965. The most recent z/Architecture model is the z14 introduced in the summer of 2017. The operating system used by these machines can be z/OS, z/VM, z/VSE, z/Linux, and z/TPF.

Generally speaking, one does not write a "mainframe" application, but instead writes an application that runs in one of the mainframe subsystems: CICS, DB2, IMS, ISPF, TSO, Unix System Services, etc. Each of these subsystems has its own strengths and weaknesses and provides an API.

The primary "claims to fame" for mainframes include

  • IBM's statement of system integrity.
  • the "future-proofing" of applications, where programs written decades previous continue to run on new hardware, new releases and version of the subsystems, and new releases and versions of the operating system.
  • Throughput and performance under load, mainframes are generally running at upwards of 90% capacity while providing subsecond response times.
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Why aren't young programmers interested in mainframes?

A key issue with mainframes is that the cohort of supporting programmers is dwindling. While normally this wouldn't be a problem in that a falling supply of programmers would be offset by an increasing amount of salary those causing a rising supply…
temptar
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How can there be so much "business logic" for a company that they cannot drop their old COBOL/mainframe code?

Something which has always confused me is this. I keep hearing about how these big, old corporations which were around in the 1950s (for example) and early on started using COBOL-coded business logic on IBM mainframes, which are apparently unable to…
user15080516
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Why were punch cards used for programming

I am doing a research essay on the history of programming languages, and I was wondering, why did programmers ever write their programs on punch cards? Didn't computer screens and keyboards already exist by the time programmers used them? I know…
Jwags
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What are the advantages of mainframes?

The downsides of Mainframes is well trodden ground; expensive, legacy, dwindling community, etc. I'm not particularly interested in the downsides, but I am curious if there are any benefits to mainframe hardware/software over the current Intel/AMD…
Scott Weinstein
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What is the difference between a server and a mainframe?

To me, it seems as though "mainframe" is a somewhat dated term; is it simply an older synonym of "server," or does it server a purpose more similar to a cluster/supercomputer?
Jules
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Are there still any companies/academic centers that use mainframes from 60s-70s?

As a young software engineer, I often hear other colleagues talk about the days of punch cards and "computers as big as the room." The earliest memories of computers that I have involve MS DOS and Windows 3.1. My question is, are there still any…
djdy
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Do you consider mainframe as part of large application deployments?

When you are setting up your system landscape for large and/or multiple application deployments, do you consider mainframe? If not, why not? If so, what factors are you considering. If you take a real TCO look at large ERP and/or consolidated…
Jé Queue
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What's new in PL/I, DB2, and S/390 assembler?

I have an upcoming technical interview with a former employer that will focus on PL/I, DB2, and ISPF. The job will be with systems that I architected and wrote myself 20 years ago. The few years of professional programming that I did since then was…
MF Dinosaur
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COBOL program or JCL?

I have to perform 3 tasks: an insert, a delete, and a write I'm not sure what the best way to do this is. My mainframe program design skills aren't too tight, so I was looking for advice. Could I avoid doing a COBOL program for this? The way I see…
Frantumn
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COBOL & Mainframe & Business

I have made a search on a Hong Kong job seeking website. There numerous of jobs titled "Computer Analyst". These are the requirements of the job: Over 3 year experience relevant working experience in IBM Mainframe environment. University degree in…
Johnson
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Program and Class Design

I am hoping you may be able to give me some advice on class design and what would be best for the program I'm currently writing. This is being done in Java and the goal is to generate letter data fields for the mainframe to read and run through a…
Tastybrownies
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How to handle multiple stories with changes on the same big Cobol program/module in a Scrum Sprint

How to handle multiple stories with changes on the same big Cobol program/module in a Scrum Sprint without ending in a mini-waterfall at the end of the Sprint? The risk is that the development sub-tasks of multiple stories are linked to each other,…
Gunther De Cock
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Correlating Search Classifiers in a Database Scan for Sensitive Information

Problem Description I am working on an enterprise data discovery project that is designed to scan databases for sensitive information. The basic search unit is called a classifier and covers things like 'Social Security Number', 'LastName',…
Josh Broadhurst
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Working Agile on Mainframe

Why do teams that work in a mainframe environment barely use an agile working methodology? What are the key factors of not doing this despite all the technology available? If so, which agile methodology would suit a mainframe environment the best?
user52999
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