Category Archives: IBM Mainframe Assembler

Videos and word documents that cover how to program in IBM mainframe assembler language.

June 3, 2020 · 6:35 pm

Marist ECC Conference – Free Online June 7-9

Marist College sponsors one of my favorite mainframe conferences each year called the Enterprise Computing Conference. This year it is scheduled for June 7-9, and it is online and free. The conference always features some interesting general talks by leading IBM and industry experts, as well as a number of smaller talks on mainframe related topics. Here is your chance to attend for free. Check out the conference schedule here: https://ecc.marist.edu/web/conference2020/welcome

Be sure to register early so you won’t miss anything. I’m sorry I won’t get a chance to visit the lovely Marist campus on the Hudson river this year, but I’m looking forward to enjoying the conference virtually. See you there.

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May 26, 2020 · 3:30 pm

Datasets for the COBOL Course

I have added a tab (Course Datasets) at the top of the blog to help provide input data for the programs referenced in the COBOL course.

In the case of input files that contain packed data, I am including a COBOL program that will produce the input file when you run it. Each COBOL program takes its own data from an in-stream dataset. I’m including the COBOL code and the JCL surrounding it to make things easier. You will have to adjust the file names.

In the case textual data files, I’m including a copy of the input data which you can paste into a member in a PDS to create the input file.

Let me know if I can help.

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May 22, 2020 · 4:36 pm

IBM’s COBOL FRIDAY WEBCAST

I had lots of fun this morning on IBM’s COBOL FRIDAY with Sudharsana Srinivasan and Paul Newton. I talked mostly about COBOL intrinsic functions, but we also considered what to do if you wanted to write something that sort of works like a user-defined function. Enterprise COBOL doesn’t support user-defined functions just yet, but it’s in the works. My work-around involves writing nested programs. You can watch the webcast here if you are interested. I also posted some sample code at the Enterprise COBOL tab that goes along with the talk. The STACKY program does dynamic allocation and creates a stack for storing pointers to records. It uses a nested programming style to create the data structure.

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April 24, 2020 · 12:41 pm

Learn You a COBOL for Great Good

The title is a reference to one of my favorite programming language instruction texts: Learn You a Haskell for Great Good. Funny, well-written and instructive. If you want to learn a functional language, Haskell is a fine choice. I still like writing in Scheme – another functional language that’s almost as old as Cobol.

But today’s topic is Cobol, which has been in the news lately, and which has a few programmers dusting off their old textbooks and manuals.  If you want to learn Cobol or brush up on your old Cobol skills, I might be able to help. I developed an online class a few years ago to use for corporate training. Now I’ve decided to publish it for general use.

You can find it here: IBM Enterprise Cobol and as a link at the top of the home page. It was built with the idea of taking a beginner and turning them into a corporate programmer. If you have some mainframe skills already, you can skip some of the beginning lessons.

The course is divided into 5 units, and if you push hard, it’s possible to get through a unit each day – a week of corporate training.  The course comes with an extensive collection of slides – 299 in all.  There are 15 programming problems that you will need to tackle and complete if you are really wanting to learn something.

You can help me by reporting any problems you have with the site or with the material.

So, … I hope this will help you learn a Cobol for great good!

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April 23, 2020 · 5:10 pm

Introduction to Macros and Conditional Assembly

In the Video Course for IBM Assembler section, I’ve added an introductory lesson on Conditional Assembly and Macro Processing. If you haven’t written macros or want to learn something about conditional assembly instructions, this guide will get you started. There’s also a link to the Powerpoint that goes along with the video.

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April 15, 2020 · 7:12 pm

What you can learn from the Cobol compiler about Assembly language

It can be fun to take a look at the assembly language listing of a Cobol program. Geeky, admittedly, but still fun. If you have never given the listings much thought, take a look at this video. You might be surprised what the Cobol compiler gets up to, and what you can learn about Cobol and assembler. In this video I examine whether to COMPUTE or not to COMPUTE, whether to PERFORM or to PERFORM THRU, and what happens when you tell the optimizer to give it the old college try.

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April 13, 2020 · 1:18 pm

It’s worse than he thought

Cobol has been in the news lately since the NJ governor asked for help with some legacy systems.  Perhaps someone should tell him it’s worse than he thought – he’s going to need some assembler programmers, too. 🙂

Some of the recent discussion of Cobol by people who should know better is amusing if it weren’t also disappointing.  You would think that Cobol died in the 1970s.  The fact is, IBM’s Cobol compiler is quite sophisticated, as is the language.  This isn’t your father’s or mother’s Cobol. It is a truly modern language, even object-oriented if you want it to be. On the other hand, writing business systems in Java, C, Python, Ruby, etc.  represents a challenge I would not like to tackle (even though I love those languages).  In many ways those languages are ill-suited to the task – for example, just doing business arithmetic in Java requires some really ugly code.

But what do I know? I still think assembler is fun to write.

One thing’s for sure: It will be fun to hear the forensics of what happened with the governor’s legacy systems. I’m guessing it has little to do with any shortcomings in Cobol.

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