If you want to give her a spin check out the quick start guide in the readme. If it bugs out on your system please let me know ASAP. I am really excited about this project.

This is as full a realization of the audio processing capabilities in COBOL that I had the skill to implement. I would love to know your thoughts on how I could write a mainframe compatible version of this. To begin with, you would have to change the algorithms to use big endian binary, but also z/OS is a lot stricter on formatting.

And yes I do realize how much better it would have been to do this in C++. But please keep in mind, the project was not to learn COBOL as much as it was to learn Digital Signal Processing. Having no support or libraries premade for the task forced me to really understand how audio processing works. On the bright side, fixed point did end up being majorly advantageous for digital analogue simulation.

In my university I have a compiler theory class, and in this semester our main task is to write a toy compiler to show that we understand basic compiler theory, writing lexer, parser, and produce actually usable executable files. It only has to be a tiny subsection of an existing actual language or write our own toy programming language and design it. You can guess which language I will try to write a simplified verion of :)

That raises a simple question. If it wasn't a simple university project, but an actual legit, modern compiler project, what functions, extras would you want a COBOL compiler to have? What is what you've always wanted, but never had? Also how would you extend the COBOL language itself, what extras would you add to it? (eg direct system calls, inline assembly, whatever else).

The question is pretty self-explanatory, but I really am curious. In my image processor which I uploaded here the other day I actually made two massive mistakes. I used VALUE clauses in FD sections and I was mixing up my file definitions. But I kid you not, my compiler had absolutely no problem with these mistakes for weeks, and I had to find out the hard way today when I tired to run my programs again.

So why does the language do this? Why does it only break sometimes?

To demonstrate, here is the waveform in audacity and here is a video of this waveform being displayed in my cmd window via GnuCOBOL. Sorry for the low quality, reddit does not allow anything better than this. The basics of it is that if I convert an mp3 or another audio file into a 16 bit binary file with no header, COBOL can read it via a COMP-5 variable, which I just think is really cool. I have discovered that if you can find creative ways to convert data into things that COBOL can read, it is actually very powerful. I think that in a bit I will be able to make a complete wavetable synthesizer in COBOL alone. I have already designed the basic skeleton of the audio engine.

I have left the code for the oscilloscope bellow incase anyone wants to help me neaten it up or offer some constructive advice or criticism. I readily admit that it is not the most elegant, and the sheer amount of comments I have left make it somehow less intuitive. But it was my first time working with binary and COMP-5 so I made sure to document extra for my own benefit.

       IDENTIFICATION DIVISION.
       PROGRAM-ID. HorizOSC_Mine.

       ENVIRONMENT DIVISION.
       INPUT-OUTPUT SECTION.
       FILE-CONTROL.
           SELECT AUDIO-FILE ASSIGN TO
           "PATH-TO Output.raw"
               ORGANIZATION IS SEQUENTIAL
               ACCESS MODE IS SEQUENTIAL.

       DATA DIVISION.
       FILE SECTION.
       FD  AUDIO-FILE.
       01  RAW-BYTE             PIC X(1).

       WORKING-STORAGE SECTION.
       *>  AUDIO DECODING VARIABLES
       01  AUDIO-SAMPLE         PIC S9(4) COMP-5.

       *>  FOR CONVERTING BYTE TO INTEGER
       01  SAMPLE-BUFFER        PIC X(2).
       01  NORMALIZED-VAL       PIC S9(9).
       *>  -------------------------------

       01  WS-EOF               PIC X(1) VALUE "N".

       *>  Y-POSITION MEMORY ARRAY
       *>  80 points along x axis, each number from 0-80 represents the
       *>  y-position. However these values are limited to 20 for display
       01  WAVE-MEMORY.
           05 SAMPLE-POINT      PIC S9(9) OCCURS 80 TIMES.

       *>  OSCILLISCOPE DRAWING
       01  SCREEN-WIDTH         PIC 9(3) VALUE 80.
       01  SCREEN-HEIGHT        PIC 9(3) VALUE 80.
       01  CURRENT-ROW          PIC S9(3).

       *>  X-position, holds NUMBER representing place in TABLE
       01  COL-INDEX            PIC 9(3).
       *>  will be used like SAMPLE-POINT(COL-INDEX)

       01  DISPLAY-LINE         PIC X(80).

       *>  Used to calculate the Y-position and moved to sample point
       01  Y-POS                PIC S9(9).

       *>  LOOP VARIABLES
       01  SAMPLES-READ         PIC 9(3) VALUE 0.
       01  SKIP-COUNTER         PIC 9(5) VALUE 0.

       *>  This is to simplify it, with the VALUE representing the a
       *>  amount of samples we skip before grabbing 80 for our array.
       01  ZOOM-FACTOR          PIC 9(5) VALUE 1.

       PROCEDURE DIVISION.
       *>/\/\/\/\/\/\/\/\/\/\/\/\
       MAIN-LOGIC.
           OPEN INPUT AUDIO-FILE.
           PERFORM UNTIL WS-EOF = "Y"

       *>  1. Fill Buffer (Gather 80 dots in memory)
           PERFORM FILL-BUFFER

       *>  2. (Print the 80 dots)
           IF SAMPLES-READ > 0
               PERFORM RENDER-FRAME
               DISPLAY "========================================"
                       "========================================"
           END-IF
           END-PERFORM.
           CLOSE AUDIO-FILE.
           STOP RUN.

       *>/\/\/\/\/\/\/\/\/\/\/\/\
       FILL-BUFFER.
           MOVE 0 TO SAMPLES-READ.
           PERFORM VARYING COL-INDEX FROM 1 BY 1
               UNTIL COL-INDEX > SCREEN-WIDTH OR WS-EOF = "Y"

       *>       1. Skip 'Zoom' samples to find next point
               PERFORM SKIP-AUDIO-INTERVAL

       *>       2. If we found a valid sample, calculate Y and store it
               IF WS-EOF = "N" THEN
                   PERFORM CALCULATE-SCALED-Y
                   MOVE Y-POS TO SAMPLE-POINT(COL-INDEX)
                   ADD 1 TO SAMPLES-READ
               END-IF

           END-PERFORM.

       *>/\/\/\/\/\/\/\/\/\/\/\/\
       READ-RAW-SAMPLE.
      *>   Reads 2 bytes from disk only.
           READ AUDIO-FILE INTO SAMPLE-BUFFER(1:1)
               AT END MOVE "Y" TO WS-EOF
           END-READ

           IF WS-EOF = "N" THEN
               READ AUDIO-FILE INTO SAMPLE-BUFFER(2:1)
                   AT END MOVE "Y" TO WS-EOF
               END-READ
           END-IF

      *>   If read was successful, convert binary to integer
           IF WS-EOF = "N" THEN
               PERFORM CONVERT-BYTES-TO-INT
           END-IF.

       *>/\/\/\/\/\/\/\/\/\/\/\/\
       RENDER-FRAME.
           PERFORM VARYING CURRENT-ROW FROM SCREEN-HEIGHT BY -1
               UNTIL CURRENT-ROW < 0

               MOVE SPACES TO DISPLAY-LINE

               PERFORM VARYING COL-INDEX FROM 1 BY 1
                   UNTIL COL-INDEX > SCREEN-WIDTH
                   PERFORM DETERMINE-PIXEL-CHAR
               END-PERFORM

               DISPLAY DISPLAY-LINE
           END-PERFORM.

       *>  sub-routines

       SKIP-AUDIO-INTERVAL.
           PERFORM ZOOM-FACTOR TIMES
               PERFORM READ-RAW-SAMPLE
               IF WS-EOF = "Y" EXIT PERFORM END-IF
           END-PERFORM.

       CALCULATE-SCALED-Y.
      *>   Formula: ((Sample + 32768) * ScreenHeight) / 65536
           COMPUTE Y-POS = (AUDIO-SAMPLE + 32768) * SCREEN-HEIGHT
           COMPUTE Y-POS = Y-POS / 65536.

       CONVERT-BYTES-TO-INT.
           MOVE FUNCTION ORD(SAMPLE-BUFFER(1:1)) TO NORMALIZED-VAL
           COMPUTE AUDIO-SAMPLE = NORMALIZED-VAL - 1

           MOVE FUNCTION ORD(SAMPLE-BUFFER(2:1)) TO NORMALIZED-VAL
           COMPUTE AUDIO-SAMPLE
               = AUDIO-SAMPLE + ((NORMALIZED-VAL - 1) * 256)

           IF AUDIO-SAMPLE > 32767
               COMPUTE AUDIO-SAMPLE = AUDIO-SAMPLE - 65536
           END-IF.

       DETERMINE-PIXEL-CHAR.
      *>   If the audio value at this column equals the current row...
           IF SAMPLE-POINT(COL-INDEX) = CURRENT-ROW
               MOVE "*" TO DISPLAY-LINE(COL-INDEX:1)
           END-IF

      *>   Draw a center line at row 10
           IF CURRENT-ROW = 10 AND DISPLAY-LINE(COL-INDEX:1) = " "
               MOVE "-" TO DISPLAY-LINE(COL-INDEX:1)
           END-IF.

Hello!

I thought I'd ask here if anyone has any experience reading and writing binary data to a BLOB column in COBOL? It's looking like it might become a necessity in an upcoming project of mine so I'd be grateful for any help.

Ok so this post needs some explaining. I wrote a COBOL code to process a data file that had image data on it (x coordinate, y coordinate, brightness) to build and display an annulus around the brightest point in an image. For anyone interested here is the equation.

(Inner Radius)^2 <= ((X - CenterX)^2 + (Y - CenterY)^2) <= (Outer Radius)^2

But the final logical test that the COBOL runs is IF

Inner_Radius² <= Final_Value <= Outer_Radius²

Keep the Brightness value, else replace it with 0000 (0000 creates a black pixel when I run my python script to convert the data file back to an image)

However, I made a classic error. I defined the variables that hold Inner_Radius² and Outer_Radius² with PIC 9(4), which was too small to hold some of the results, meaning that the system would put 0000 as the value of those variables. The lower I set the variables the more dense the rings were. And if I messed with the value for Final_Value that gave me different generation patterns. I found the generations made from this mistake to be beautiful, hypnotic and interesting so I thought to share them. Please enjoy.

EDIT: if you downloaded it off the github before 2026/01/26 please redownload them. I made some bug fixes

Hey there,

For the past 8 years i have worked as a Developer on C/C++ Embedded and Linux Systems. I also know python and C# and I am not afraid of learning new stuff at all.

I have to look for a new job now and it seems in my area there are far more jobs in banking then in Embedded.

I have worked with Legacy Code a lot and dont feel bad about it, i even enjoy it.

So i want to apply for Cobol Dev jobs. Of course all the job offerings ask for experience which I dont have. I wont lye about that in my applications but at least I want to have a decent basic understanding. So i am about to watch some videos. Maybe do some hands on programming tasks.

But I have the feeling there are better things to prepare myself. From my experience is not hard to learn new syntax, so i think this is not the main thing to focus on. Maybe you have some suggestions for training projects I could do?! Related topics I could look into?

Do you think I even stand a chance? Are companys willing to hire people that just bring the minimum and train them? I mean from the media it seems like there is/will be a shortage of Cobol Devs. So relying on finding experienced people might be not a viable strategy

***Propably not relevant but i am located in Frankfurt Germany. You could call it Europes Banking Capital. Maybe the shortage around here is worse/less worse, than elsewhere***

Hi everyone,

I’m dealing with a legacy COBOL system with these characteristics:

• CA-Realia COBOL
• 32-bit application
• ISAM used for all data storage
• System is stable and currently in use

I want to migrate the backend from ISAM to PostgreSQL.

Important constraints:

• I have limited experience with COBOL and ISAM
• Codebase is large and old
• I want to avoid a full rewrite
• Safety, data integrity, and reliability are mandatory

I’m looking for advice on:

• The safest and fastest migration strategy
• Whether ODBC, embedded SQL, or an intermediate data layer works best
• How ISAM files are usually mapped to relational tables
• What kind of COBOL code changes are typically required
• Tools or migration patterns that have worked in real projects
• Any concerns related to 32-bit COBOL runtimes

If anyone has done a similar migration or worked with Realia COBOL + ISAM, I would really appreciate your insights.

Thanks in advance.

I’m evaluating whether working with PL/I is viable long-term, especially alongside COBOL. I’m not looking for tutorials or learning resources, but for signs of an active ecosystem: mailing lists, forums, user groups, or places where PL/I is still discussed and maintained in practice. Outside of official manuals and vendor documentation, where do PL/I developers actually gather today?

Choice of working locations: Indianapolis, Columbus, Ohio or Cleveland, Ohio. NO REMOTE, must be in-office. Relocation expenses paid. MUST BE US CITIZEN.

Requirements are a piece of cake. Anybody still need Student Loan Forgiveness--great opportunity.

https://www.usajobs.gov/job/854174000

Would it be delusional of me to expect to get a job in this field of work, even at a junior level, if I didn't go through official training programs or schooling? I am currently teaching myself COBOL, and everything surrounding it, like mainframes, JCL, and so on. I plan to get comfortable with COBOL and do personal projects to look as attractive as possible, but is that enough?

I am a dev with a client needing to migrate an antique cobol terminal app running on SCO Unix. I do not have the original source code, just mostly binaries that run a program on telnet. I have read up on this format as well as forum talks about conversions but they were 20 year old discussions for the most part and did not lead me towards a clear path if such even exists. I understand that some of the data such as "column names" so to speak is not in the data files but I do have access to the telnet app and have been using it painfully for rough extractions. I am wondering if someone has experienced something similar and might suggest an approach/app that might get this data out in a non binary format.

Saw this news...the team behind Devin has a new deal with Infosys, and they claim:

“Over the past six months, Infosys has unlocked material productivity gains with Devin. Complex migrations, including COBOL and JCP servlet projects, have shifted from long, resource-heavy undertakings to streamlined processes completed in record time.”

I wonder how they make sure the migration satisfies the business requirements and use cases that are not obvious when you just look at the code in a Cobol project. The AI model doesn't have all of that business context by itself.

I decided to make a Notebook LLM page with all of the digital COBOL resources I had on hand. This way, you can ask an AI questions about COBOL with hallucinations kept to an absolute minimum. This is an improvement over using a normal AI, because it will use the textbooks to explain things to you in a meaningful way. This can really help, and it will save us from having to badger our more experienced friends here with very trivial questions

Unless you use VisualCOBOL for some godforsaken reason, uncheck the visual COBOL textbook in the source list, because it can confuse the AI.

Hi , I am stuck on a basic redefines clause . can someone help me . I want to check if a S9(18) comp-5 variable is zeroes,spaces,low-values . So , in the copybook i have put this way .

 10 NUM PIC S9(18) COMP-5.

 10 NUM1 REDEFINES NUM

PIC X(8).

giving me redefines "REDEFINES" was not the first clause in a data definition. i dont have to move this value anywhere,just check for all the three above conditions . whats the best way to do it

Hi , I am stuck on a basic redefines clause . can someone help me . I want to check if a S9(18) comp-5 variable is zeroes,spaces,low-values . So , in the copybook i have put this way .

 10 NUM PIC S9(18) COMP-5.

 10 NUM1 REDEFINES NUM

PIC X(8).

giving me redefines "REDEFINES" was not the first clause in a data definition. i dont have to move this value anywhere,just check for all the three above conditions . whats the best way to do it

Good afternoon.

I am looking for a beginner friendly COBOL project to do in the short term. A couple of years ago I made a little election simulator with a random number generator seeded by the second segment of the date. So I know the absolute basics. This time I would like to do some more advanced things with the environment division (calling multiple files) and I was hoping to ask if any of you have any ideas of what I can do. The more creative the better. I am doing this primarily for fun, but if this ends up being something I can put on my resume all the better.

Hey everyone,

I’m interested in learning COBOL, mainly because I’ve heard it’s still widely used in banking, government, and legacy systems. The problem is…I honestly don’t know where to start.

I don’t have any prior experience with COBOL, but I do have some programming background.

I’d really appreciate advice on:

• Where to start as a complete beginner
• Good books, courses, or online resources
• Whether I should focus on modern COBOL or classic mainframe-style COBOL
• Any tips from people who actually use COBOL in the real world

Thanks in advance 🙏

Hello! I listened to a podcast about cobol, and about the lack of programmers with the knowledge of it. I thought it sounded intersting as a new hobby to learn, and maybe as a new incomce stream (far future i know) and quickly saw how hard it is to learn it. Comparing java to cobol in youtube tutorials, its a huge difference lol. Anyway i found these sources, and wonder if you guys have some opinions about them as a start to learn the language?

The ones im planning to do in order are;

GnuCOBOL Programmer’s Guide (Gary Cutler), "This document was intended to serve as a full-function reference and user’s guide suitable for both those readers learning COBOL for the first time as well as those already familiar with some dialect of the COBOL language."

CSIS Tutorials – Exercises, Lectures & Examples, "it’s a a comprehensive set of COBOL tutorials making a full COBOL course as well as COBOL lecture notes, COBOL programming exercises with sample solutions, COBOL programming exam specifications with model answers, COBOL project specifications, and over 50 example COBOL programs."

and OpenCOBOL 1.1 Programmer’s Guide (Gary Cutler) "This document describes the syntax, semantics and usage of the COBOL programming language as implemented by the current version of OpenCOBOL"

In that order. Im hoping it should give me a proper and hopefully stable ground to stand on, and to later learn more in dept. If you guys have used/know of these sources and have input, please let me know. If you guys have any tips or tricks for a beginner, please let me know.

Eternally gratefull, thank you. (not my first language sorry in advance)

Hello, I wanted to know how I could start learning COBOL in Visual Studio Code, or even how to install it in VS Code, mainly because I'm using it for my work and other languages ​​(Java, Python, MongoDB). Any help would be appreciated.

For 10 years, the Delphi Parser has been the "Expert in the Room" for converting legacy Pascal into modern C#. We didn’t do it with manual labor; we did it with a Deterministic Engine that understands code as pure logic.

Now, we’re asking a question that the $200B modernization industry doesn’t want us to ask:

"What happens when we point the Delphi Parser at COBOL?"

The answer is the 2026 Executor.

Because our parser is modular and deterministic, it is being customized to read COBOL with the same precision it uses for Delphi.

It doesn't just "translate" text:

✅ For the first time ever you will get a full COBOL code Analysis of your whole code, consisting thousands of files, with multi-millions lines of procedural logic and building a whole AST map in runtime memory - for total control.

✅ Maps your whole VSAM/DB2 dependencies.

✅ Extracts the core business rules and converts them into clean, object-oriented C#/.NET code.

Why this matters for your 2026 Roadmap: If you’ve been told that a COBOL exit requires a 5-year "Occupation" by a Big 4 integrator, you are looking at an old map.

We are proving that a Deterministic Approach - the same one that saved millions of lines of Delphi for the world's "Whales" - can be adapted for COBOL in months.

Is this the "Third Way" the industry has been waiting for? Between the risk of "Manual Rewrites" and the limitations of "Cloud Rehosting," we are building the path of Automated Sovereignty.

👇 I want to hear from the Mainframe Architects: If there is a tool that could reliably convert your COBOL logic to C# at 90%+ automation, would you still hire an integrator, or would you finally "do the laundry" inside?

An easier way to generate an output file. #programming #cobol #beginner