KICKS/COBOL to Python Conversion

A complete, working example of modernizing CICS/COBOL applications to Python web applications

🎯 Overview

This project demonstrates the full conversion of Doug Lowe’s classic CICS sample application suite from KICKS/COBOL running on MVS 3.8J to a modern Python Flask web application.

What You Get

✅ Working Python/Flask Application - Run it immediately
✅ Original COBOL Source Code - See the before and after
✅ Complete Documentation - 60+ page conversion guide
✅ Real Production Patterns - Not just theory

🚀 Quick Start

# Clone the repository
git clone https://github.com/tsiitz/kicks-to-python.git
cd kicks-to-python

# Install and run
pip install -r requirements.txt
python app.py

# Open http://localhost:5000

Sample Customer Numbers: 400001, 400002, 400003, 400004, 400005

📚 Documentation

Getting Started

Conversion Guide

Reference

🔑 Key Features

Converted Programs

Transaction Original COBOL Python Route Description
INQ1 CUSTINQ1 /customer/inquiry Basic customer inquiry
INQ2 CUSTINQ2 /customer/inquiry2 Inquiry with browse (PF5/6/7/8)
INQ3 CUSTINQ3 /customer/inquiry3 Inquiry with invoices
MNT1 CUSTMNT1 /customer/maintenance Add/Change/Delete
MENU INVMENU / Application menu

Conversion Highlights

VSAM to SQL:

EXEC CICS READ FILE('CUSTMAS') INTO(CUSTOMER-RECORD) RIDFLD(KEY) END-EXEC

↓↓↓

customer = customer_repo.find_by_number(customer_key)

File Browse to Pagination:

EXEC CICS STARTBR FILE('CUSTMAS') RIDFLD(KEY) END-EXEC
EXEC CICS READNEXT FILE('CUSTMAS') INTO(RECORD) END-EXEC

↓↓↓

customer = customer_repo.get_first()  # PF5
customer = customer_repo.get_next(key)  # PF8

BMS Maps to HTML:

📊 Architecture Comparison

Original Mainframe Stack

┌─────────────────────┐
│   3270 Terminal     │ ← User interface
└──────────┬──────────┘
           │
┌──────────▼──────────┐
│   CICS Region       │ ← Transaction processing
│  ┌───────────────┐  │
│  │ COBOL Programs│  │
│  └───────┬───────┘  │
│  ┌───────▼───────┐  │
│  │  BMS Maps     │  │
│  └───────────────┘  │
└──────────┬──────────┘
           │
┌──────────▼──────────┐
│   VSAM Files        │ ← Data storage
└─────────────────────┘

Modern Python Stack

┌─────────────────────┐
│   Web Browser       │ ← User interface
└──────────┬──────────┘
           │ HTTP/HTTPS
┌──────────▼──────────┐
│   Flask Server      │ ← Web framework
│  ┌───────────────┐  │
│  │ Python Routes │  │
│  └───────┬───────┘  │
│  ┌───────▼───────┐  │
│  │Jinja2 Templates│ │
│  └───────────────┘  │
└──────────┬──────────┘
           │
┌──────────▼──────────┐
│  SQLite Database    │ ← Data storage
└─────────────────────┘

🗄️ Data Model

Customer Master (VSAM CUSTMAS → SQL customers)

COBOL Field COBOL Type SQL Column SQL Type
CM-CUSTOMER-NUMBER PIC 9(6) customer_number INTEGER PRIMARY KEY
CM-FIRST-NAME PIC X(20) first_name VARCHAR(20)
CM-LAST-NAME PIC X(30) last_name VARCHAR(30)
CM-ADDRESS PIC X(30) address VARCHAR(30)
CM-CITY PIC X(20) city VARCHAR(20)
CM-STATE PIC XX state CHAR(2)
CM-ZIP-CODE PIC X(10) zip_code VARCHAR(10)

Additional Tables:

🎓 Learning Resources

For CICS Programmers

If you’re a CICS programmer looking to understand modern web development:

  1. Start Here: Complete Conversion Guide - Full CICS to Python patterns
  2. Then Read: Python Application Guide - Understanding the converted app
  3. Practice With: The working application - clone and run python app.py

For Python Developers

If you’re a Python developer working with legacy systems:

  1. Start Here: Complete Conversion Guide - Understand CICS concepts
  2. Then Read: COBOL Source Documentation - Original COBOL programs
  3. Study: Compare COBOL source with Python implementation

For Everyone

🛠️ Technology Stack

Python Application

Original COBOL

🎯 Use Cases

Enterprise Modernization

Use this project as a reference for:

Education

Perfect for:

Development

Great starting point for:

📖 What’s in the Repository

kicks-to-python/
├── app.py                          # Flask application
├── models.py                       # Data models
├── database.py                     # Database layer
├── templates/                      # HTML templates
│   ├── base.html
│   ├── customer_inquiry.html
│   ├── customer_inquiry2.html
│   ├── customer_inquiry3.html
│   ├── customer_maintenance.html
│   └── ...
├── cobol-source/                   # Original COBOL
│   ├── CUSTINQ1.cbl
│   ├── CUSTINQ2.cbl
│   ├── CUSTMNT1.cbl
│   ├── INVMENU.cbl
│   ├── bms-maps/
│   └── README.md
├── docs/                           # Documentation
│   ├── index.md                    # This page
│   ├── _config.yml                 # GitHub Pages config
│   └── ...
├── KICKS_TO_PYTHON_CONVERSION_GUIDE.md  # 60+ page guide
├── requirements.txt                # Python dependencies
└── README.md                       # Repository README

🤝 Contributing

We welcome contributions! Here’s how you can help:

Code Contributions

Documentation

Feedback

📄 License

This project is licensed under the MIT License. See the LICENSE file for details.

Attribution:

🙏 Acknowledgments

This project builds upon the excellent work of:

📞 Support

Need help? Here are your options:

🌟 Star the Repository

If this project helps you, please give it a star on GitHub! ⭐

It helps others discover this resource for mainframe modernization.

⭐ Star on GitHub →

🔗 Quick Links

Documentation

Resources

**Made with ❤️ for the mainframe modernization community**