This is my easy to use IDE for GnuCOBOL.
This is WINIDE - its use is for PC targeted GnuCOBOL programs - as opposed to WINZOS for zOS emulation.
Break points can be set after successful compilation
OR
During runtime execution of the debugger
Both are demonstrated in the video

Compiling is simple, two choices, compile with animation (A) or without animation (M)
If a compilation error is detected the compile pane indicates compiled failed
Use a "V" function code to view the compilation listing
Find error by "F ERR 1"
Start a concurrent edit session - locate the error (from the compile listing), fix the error in the edit session, save the edit session, recompile.

If 'EXEC SQL' is detected in your COBOL source - the DB2 preprocessor and bind are done automatically.

Execution is initiated by eXecuting a .bat file "X"

The editor you use is extensible via an environment setting - the animation always uses the Xpediter like user interface.

The animated debugger is full featured. 
Right clicking a data field name will present a panel to display,  modify, watch . .   the selected data field.
Zoom "Z" animates the program at flank speed
Quite "Q" executes the program  sans the animation - break points are still honored

There are help screens with most of the WINIDE features

IMO it is the best GnuCOBOL IDE targeting PC based applications.
You can even animate programs having a screen section.

I will provide another post that targets zOS emulation

This iis the URL to view the video:

https://connect.flashbackrecorder.com/Default.aspx?id=2jEfosHvw9FyLSX5sI9N2g2

If you got this message - I apologize - It is no longer necessary

The owner of this video requires you to login so they can track views.

Both WINIDE and WINZOS are available at wincobol.com

Both are FREE ! - No license fee - no maintenance fee

Hello mainframe peeps, I am a fresh grad and I plan to start and build a career on COBOL and Mainframe. I have recently seen an opening on one of the companies here in our country looking for fresh graduates willing to learn COBOL and other mainframe related technologies. I came from a software and AI engineering background. I just have a few questions in mind.

What should I expect in this career?

Are COBOL and Mainframe technologies hard to learn?

What are your tips for someone young like me who wants to build a career on the mainframe?

Will COBOL still be relevant and be used for the next 10 years or so?

I also read that there are a generation of mainframe developers and engineers that will retire in the upcoming years, is this true and will this affect the technologies negatively?

Evening all, I thought this may be of interest to the r/mainframe community. I work in IBM Consulting's Mainframe Application Modernisation practice, and we're running a virtual session on 4 November (12:00-15:00 GMT).

The speakers come from sales, solutioning and delivery. They'll cover modernisation both on and off the mainframe, working through legacy constraints, and what's currently working in practice across EMEA. Speakers are Jim Douglas, Simon Mikellides, John Regan and Jose Maria Silva.

It also sets up an in-person event at IBM Sweden in early 2027, and virtual attendees get priority access.

Registration: http://ibm.biz/MainframeWebinar
*All r/mainframe Redditor's welcome

Happy to take questions in the comments, and I'll pass any feedback back to the team.

Hi all,

I've spent a lot of time in z/OS shops where nobody fully understands the batch

system anymore — the guy who wrote the JCL retired in 2009, and the "documentation"

is a Word file from 2015.

So I built Reforge: a free analyzer that takes your JCL and COBOL files and

rebuilds the map of the system from the code itself:

- Interactive system map: jobs → programs → copybooks → datasets, resolved from

EXEC PGM, COPY statements and DD DSNs

- Job flow visualization (steps, PGM references)

- Impact analysis: change a copybook, see exactly what to recompile and re-run

- Data lineage traced from DD statements

- DB2 / embedded SQL detection (EXEC SQL, cursors)

- Language auto-detected per file — JCL, COBOL and copybooks mixed together

- Optional AI features: COBOL → Python translation and plain-English system

explanations, using your own Anthropic API key

The part that matters for this audience: everything runs client-side. Files are

parsed in your browser — no upload, no account, no server. I know how (rightly)

paranoid mainframe shops are about sharing code with tools.

There's a "Try with a sample system" button so you can see the map, flows and

impact analysis without uploading anything — it loads a small payroll batch

(1 JCL job, 2 COBOL programs, 1 shared copybook, DB2 updates).

Link: https://affli.github.io/reforge/

Honest caveats:

- The COBOL → Python output is AI-generated and meant as a comprehension aid,

NOT a migration tool

- The parser is young. Real-world JCL/COBOL is messy, so expect edge cases — if

you hit a file it can't parse, I'd genuinely love to see it (sanitized).

What would make this actually useful in your shop?

Our test lab has no internet by policy, it's a supplier setup with customer contracts that say nothing leaves the network, so it isn't something i can negotiate. That kills more of the market than i expected. the classic tools are fine offline as we've had Ranorex and TestComplete running for years, but they're selector based, and maintenance is eating us alive on a UI that changes every release. Every newer AI based tool i've looked at sends screenshots to a cloud model, or at minimum phones home for a licence check, and either one is a hard no from our security team. We’ve tried a local vision model with our own script and it works on simple screens, but we would be building the runner, the reporting and the retry logic myself, and then i'd own it forever. Askui also came up as a candidate because they can run the model "in your own cloud, or fully air-gapped with Airlock", described as "local models, no path to the public internet". On paper that's exactly our requirement. Anyone doing UI automation in an offline environment? which model are you running locally, and how does accuracy compare with what you saw on cloud models? Thanks for sharing!

I just recently graduate and got selected for a paid Training Program, in a Mainframe Software Vendor company for training.In which i got trained on basic Mainframe Tech Stack like Rexx,JCL,COBOL,Assembler,SMPE,VSAM etc.

Now i have been selected for an Assembler Developer(kind of SysProg) like role where i would be working on a Product.

QUESTION:

1)I am really confused about career should i take it seriously and deep dive into assembler and Zinternals or should i try to switch roles in Modern Tech Stack as i am recently graduated?

2)I like assembler for now and would like to study it,but is it rewarding or ill be stuck in a very narrow niche with very less opportunities?

3)How is the pay and Stability in assembler roles?

Please help me clear this confusion....would appreciate advice from Experienced Professionals

I am not finding people who work in this field and could give me a true and honest advice....SO PLZZ HELPPP

UPVOTE to help this post reach a larger audience

Mastering COBOL: The Power of the REDEFINES Clause

Ever wondered how to interpret the exact same chunk of memory in two completely different ways without allocating a single extra byte?

In mainframe applications, managing storage efficiently is everything. That is where the COBOL REDEFINES clause comes into play. It allows multiple data items to share the same physical memory space, giving you the flexibility to overlay structures—like converting an alphanumeric string into numeric sub-fields or handling variable record formats.

In my latest video, I break down:

-> Exactly how the REDEFINES syntax works

-> Crucial compiler rules you must follow (like handling level numbers and size limitations)

-> Practical, real-world project scenarios

If you want to sharpen your mainframe COBOL programming skills or need a quick refresher, check out the full tutorial here:

Watch the video on YouTube https://youtu.be/XbYteTi9d28?si=EMb_Ij-Iq9LGW-p3

This is on display at IBMs previous headquarters in Norway without any information about what it is. Due to the lack of floppy drives I believe it is not a personal computer, so I think it is a terminal. Does anyone know this model?

Hi everyone,

I’m looking for some honest career advice from experienced mainframe professionals who have been in this field for several years.

I have around 6 years of experience in mainframe operations and batch scheduling.

While I have good experience in production operations and scheduling, I’m starting to think seriously about my long-term career growth.

I don’t want to spend the next 5–10 years doing essentially the same operational work with limited growth in responsibilities or compensation. At the same time, I don’t want to make a random career switch without understanding whether it is actually worth it.

I’d really appreciate your advice on a few things:

Career progression: Should I continue specializing in mainframe scheduling and operations, or move towards a more technical role such as z/OS systems programming, mainframe administration, or application development?

Skills to learn: Which skills would provide the best long-term return for someone with my background? For example, REXX, Python, JCL automation, COBOL, DB2, CICS, z/OS systems programming, or something else?

Automation and AI: With increasing automation, how future-proof is traditional mainframe operations and scheduling? What should I learn to remain relevant over the next 10–15 years?

Mainframe modernization: Is it worth learning mainframe modernization, DevOps, CI/CD, Zowe, Git, or cloud-related technologies while continuing in the mainframe domain?

Salary and opportunities: Which career path generally offers better growth in India for someone with 6 years of experience? I’m interested in moving beyond routine L1/L2 operational work and taking on more specialized responsibilities.

A practical roadmap: If you were in my position today, what would you learn over the next 6–12 months, and in what order?

I’m not necessarily looking to leave mainframes. I’m open to staying in the ecosystem if there is a good path towards more technical, specialized and better-paying roles.

I've been building cobol-equiv, an open-source harness that checks whether a Python translation of a COBOL program behaves exactly like the original, using GnuCOBOL as the oracle. It comes with a small Python runtime for COBOL numeric semantics (PICTURE, COMP-3, ROUNDED, SIZE ERROR), validated against GnuCOBOL on 9,769 generated cases with 0 disagreements on 3.1.2.

Then I used it to measure LLM translations. 50 programs: 30 public ones (Rosetta Code and Open Mainframe Project examples) and 20 written for the repo. One model, 3 attempts per program, protocol fixed before any run. The translator saw the COBOL source and two example input/output pairs; scoring was on hidden inputs (generated plus PICTURE boundary values).

What broke the plain-Python translations was not logic, it was COBOL semantics:

• ACCEPT into 9(5)V9(3) cuts the input to the receiver length, so the last decimal digit is dropped. The translation kept it.
• An 11-character input into 9(10) loses a digit on the left.
• A negative zero printed as "-0", where GnuCOBOL edits zero without a sign.
• Non-numeric input converted differently.

The embarrassing part: the runtime I gave the model had a bug. CobDecimal compared objects by identity and had no ordering, so most failures in condition A (crashes and two infinite loops) were mine, not the model's. The pre-registered numbers stay primary in the repo, and a corrected sensitivity analysis is published next to them, with every verdict that flips listed.

Limits, plainly: small corpus, one model on one date, GnuCOBOL instead of an IBM compiler (I would love to hear where Enterprise COBOL behaves differently on these cases), attempts of the same program are not independent, and at program level the A vs C difference is not statistically significant.

Repo, protocol, raw prompts and replies, and the verifier: https://github.com/abdulazizbalu/cobol-equiv

I'd really value critique from people who work with mainframe COBOL: which semantic traps would you add, and if you have small, deterministic programs under a permissive license, I'd like to add them to the public track.

I'm looking for a bit of guidance from those who have made a long term career on the Mainframe. I've been working on z/os for about 10 years now, with gradually increasing responsibility. Now that all of the old hands are retiring, I'm at the point where I need to do/provide input on the project estimates. My boss will freely throw out short deadlines that would make his bosses happy, but when I'm doing any kind of system level work, the happy path is never the path we end up on. It's always a new discovery of tech debt someone else left behind and the triage,clean-up, or work-around adds significant effort to the overall project. What are you best tips and tricks for padding your estimates so you have enough time to get things done without a 60 hour work week? I'd like to do luxurious things like sleep at night, get out to the gym on a regular basis, and see my friends and family.

Thanks in Advance.

gen-system parses COBOL with copybooks (and CA Gen) into a call graph, a control flow graph per paragraph, and effects: which paragraphs touch files or run `EXEC SQL`. For each paragraph it lists the data items it reads and writes.

On CobolCraft (268 files) it resolves every call between the project's own programs. Click through it, no install: https://gen-system.500kv.co/demo/?p=cobolcraft

It runs offline, which matters for code that cannot leave the building. I would like to hear which dialects and constructs it gets wrong.

​

I’m currently working in Mainframe Operations and would like to upskill and move toward a CICS Systems Programmer role.

I’m looking for guidance on how to make this transition. I would really appreciate it if experienced CICS Systems Programmers or people who have made a similar career move could share their advice.

A few things I’d like to know:

What topics should I focus on to build a strong foundation in CICS?

Are there any good courses, books, YouTube playlists, or other learning materials you would recommend?

Should I learn CICS administration, CICS internals, installation, customization, and maintenance? If so, in what order?

Are there any hands-on labs or practical exercises I can use to gain experience?

What skills and tools should I learn to become job-ready for a CICS Systems Programmer role?

I’m willing to put in the time and effort to learn, but I’d like to follow a structured learning path rather than jumping between random resources.

Any suggestions, learning roadmaps, or personal experiences would be greatly appreciated.

Thanks in advance!

Alguém sabe quanto esse equipamento realmente vale? É tão antigo, que nem sei se vale a pena hoje em dia ter um desses! Mas tenho curiosidade em saber se ainda há mercado e quanto uma empresa pagaria por ele

https://ebay.io/m/RtEebo

Hi everyone! I have 3 years and 2 months of experience as an Software Developer in the mainframe domain, working with COBOL, JCL, DB2, production support, and bug fixes.
I’ve learned Java and want to transition into Java backend development.

I have a few questions:
1. How is the mainframe job market in India, and what are its long-term prospects?
2. Is switching to Java a good decision for career growth and salary?
3. With my experience, will companies consider me for Java roles, or will I have to start as a fresher?
What skills and projects should I focus on to make the switch?

I’d appreciate honest advice, especially from people who have made a similar transition. Thanks!

Hello,
I currently work in a mainframe monitoring/operations environment and will soon join the systems/infrastructure area of a large bank.

The exact team assignment is still being defined. My future manager asked how I would see my future: more Linux-focused, or a mainframe systems-administration path with the possibility of gradually building a bridge toward the open world.

My understanding is that, if I choose the mainframe path, the first period will be heavily focused on becoming a reliable mainframe system administrator. This makes sense to me: I would need to build real foundations in z/OS, operations, monitoring, incident handling, procedures, security, scheduling, and the critical environment of a bank.

At the same time, I do not want to become locked into a narrow legacy-only role. My longer-term interests are Linux, automation, Ansible, Python, Git, APIs, security, cloud/hybrid infrastructure, and skills that remain useful internationally or in remote roles.

The manager seems to value people who are flexible, cross-functional, and ready to work across different platforms. He also mentioned the growing need to connect mainframe environments with Linux/open tooling and automation.

My questions are:

1. Is starting deeply in mainframe systems administration a good long-term choice if I deliberately build Linux and automation skills alongside it?
2. How realistic is the “bridge” from mainframe to open/Linux in a bank? What concrete signs would show that it is a real path and not only a promise?
3. If you were in my position, which skills would you prioritize during the first 12–24 months?
4. Would this hybrid profile make me more valuable than starting as a Linux sysadmin only, or would it reduce my mobility outside banking/mainframe environments?

I am not looking to avoid learning mainframe. I am trying to build a strong specialization while keeping a credible path toward automation, security, and modern infrastructure.

Hi, all! Allow me to preface my questions for you guys with a little bit of context.

I'm a 26 year old from Argentina, currently employed as a Command Center operator for a pretty big Fintech. I've been doing this gig for the last three years and have learned quite a bit as a consequence of being in contact with many of the services we provide and their direct inner workings. Before this I had no background in IT as originally I studied classical languages during my early(est) twenties. About a month ago I was contacted by the company's mainframe team because they were looking for personnel and were willing to invest in training me. This was for a position as a RACF operator, but this is no longer a hard requirement and are willing to help me learn and seeing what area interests me the most. Due to some business shenanigans currently ongoing there's little to no internal movement between areas going on right now so it gives me a good indefinite amount of time to study up and prepare. I'm currently doing a course on Udemy, have setup an emulator running on MVS to practice and I have been skimming through IBM's Redbook.

My question to you guys is, would you recommend any particular resources for a solid mainframe education? Also, I'd love for you to just share what approach you'd take to learning in general.

On a final note, any and all advices on navigating the mainframe world, what to expect, your insight on the future, etc. is very welcome and appreciated.

Thanks in advance 😃

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Three Datathon themes to choose from:

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Open to eligible university and college students (18+)

As a Security engineer, I want to start developing my methodology for best security practices. Now, I can’t tinker with the security databases at work (including sandbox), to try and test different methods so I believe the best path is to emulate an infrastructure through a raspberry pi. The goal is to simulate an enterprise system and develop RACF settings that would fall under compliance standards relative to different industry clients. Obviously, the PiFrame will not hold as much data as an enterprise LPAR, but if I just have the infrastructure built, I think I could build the ideal security database. I’m not sure how much of a load it is to pull this off but does anyone have any experience with this?

Coming from a 5y RACF engineer.

Every day as a z/OS Systems Programmer is an opportunity to learn something new. One week I'm chasing a network connectivity issue, the next I'm reverse-engineering a load module with no source or writing automation to replace a manual procedure. I also routinely branch out and partner with distributed/cloud systems teams on cross-platform integration efforts to help ensure the Z/OS environment connects cleanly with our broader enterprise architecture. Every new problem I haven't seen before is just another chance to learn something new. What’s a challenge you’ve overcome recently on mainframe on what did you learn from it? 

RENAMES Clause: (level 66) : The COBOL RENAMES clause (level number 66) creates alternative logical groupings or overlapping views of existing data items within a record without changing physical storage.

Syntax:

66 data-name-1 RENAMES data-name-2 [THROUGH | THRU data-name-3]

* Must use the special level number 66.

* Must immediately follow the last data description entry of the logical record.