Questions tagged [mainframe]

The mainframe tag refers to the class of "big iron" computers, primarily those from IBM. Currently this is limited to the IBM Z hardware, typically running z/OS, z/VM, z/VSE, z/TPF, or a distribution of Linux on IBM Z as its operating system.

Mainframe computers, while often thought of as dead technology by most, are nothing of the sort.

They are still used in a huge number of environments where reliability, availability and serviceability (RAS) are key requirements.

These aren't your grandfather's mainframe; these beasts have been evolving along with the rest of the computer industry and there's nothing that can match them in raw, insane, transaction processing throughput.

This tag should be used when asking questions related to the IBM Z hardware (the "Z" stands for zero downtime).

IBM provides the z/OS basic skills education Knowledge Center, click on the table of contents link for a list of topics.

Related tags and searches:

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How to use the C socket API in C++ on z/OS

I'm having issues getting the C sockets API to work properly in C++ on z/OS. Although I am including sys/socket.h, I still get compile time errors telling me that AF_INET is not defined. Am I missing something obvious, or is this related to the fact…
Jax
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What is the meaning of char foo(|10|) in C?

I'm a very experienced C programmer, but recently I came across some code on a mainframe that has a local variable. This is in a simple C function that declares this variable, and then strcpy / strcats two strings into it, and then tries an…
gbronner
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What is the difference between a variable-blocked format and a fixed-blocked format?

I have encountered these terms in a data file definition document for some data that I'm getting from a Mainframe system. I failed to find definitions of these terms in any glossary or Google search - just mentions of them. Can anyone shed some…
user1845848
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DB2 database in Oracle SQL developer

I've heard it's possible to connect to a mainframe DB2 database with a client like Oracle SQL developer. I've looked on-line and can't seem to find the connector files needed to do this in SQL developer. Can anyone direct me to a link to make this…
Frantumn
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equivalent of ftp put and append in scp

I have a legacy script which I am not able to understand. The script is to transfer 4 files (2 ebcdic format files and 2 pdf files) in unix to mainframes through ftp. ebcdic format file 1 is abc.xyz ebcdic format file 2 is pqr.xyz pdf file 1 is…
Vicky
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What are the advantages of pseudo conversational vs conversational CICS programming?

I am trying to understand the differences between pseudo conversational and conversational CICS programming. What are the advantages and disadvantages of each approach?
Richards Marian
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Dynamically Reading COBOL Redefines with C#

I'm making a C# program that will be able to dynamically read an IBM HOST Copybook written in COBOL and generate an SQL table off of it. Once the table is generated I can upload a file into my program and it will read, convert from IMB-37 and insert…
Daniel Dennis
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How do I select distinct count over multiple columns?

How to select distinct count over multiple columns? SELECT COUNT(DISTINCT col1, col2, col3) FROM table; Is there a working equivalent of this in DB2?
Tonan
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Why don't mainframe applications have bugs?

It seems like old iron is rock solid software. Why is that? Is it because the software is so mature, that all the bugs have been worked out? Or is it because people have gotten so used to the bugs that they don't even recognize them and work…
Josh
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COBOL - Differing answer from mainframe to PC for same COMPUTE

I have this very simple dummy COBOL program which does a dummy COMPUTE and displays the result. ID DIVISION. PROGRAM-ID. DUMMYPGM. DATA DIVISION. WORKING-STORAGE SECTION. 01 NUM-A PIC 9(3) VALUE 399. 01 NUM-B PIC 9(3) VALUE 211. …
Gael L
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What language is this: PROC, VERIFY, DECLARE, SCREEN, CMS,

I have to find some logic from an old legacy code. My manager says is COBOL, I'm not sure about it. I have tried to find some keywords on cobol tutorials without any luck. Here are some code snippets: PROC(&QPROG); VERIFY OFF PROC;DECLARE &MSG1 AS…
Neir0
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Teaching myself Z/OS assembler

I’ve interned at a company that does a lot of mainframe work. Most of my mainframe experience has been using Java and Unix System Services. I’ve had some experience with the ISPF interface and C but none with assembler. I’m graduating shortly and…
Jared
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Learning mainframe & JCL with Java/OOP/SQL background

I've been coding and managing Java & ASP.Net applications & servers for my entire career. Now I'm being directed towards involvement in mainframes, ie z/OS & JCL, and I'm finding it difficult to wrap my head around it (they still talk about punch…
Tim
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What is the logic behind COBOL paragraph numbering?

I've seen the following paragraph naming structure lots of times: nnnn-PARAGRAPH-NAME. Where nnnn stands for a 4 digit number. Here is a complete example: 0000-MAINLINE. PERFORM 1000-INITIALIZE-THE-PROGRAM. PERFORM…
mllamazares
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How to unpack COMP-3 digits using Java?

I have huge mainframe file and there are some packed digits in that file. I would like to know how to unpack following digit using java? packed digit : ? I read tutorials for unpacking digits and found the following rule to count the number of bytes…
Shekhar
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