CICS Mastery
The Complete Reference Course
IBM CICS (Customer Information Control System) powers the world's most critical online transaction systems — banking, insurance, retail, and government. This course takes you from zero to production-ready, covering every CICS concept with practical COBOL examples.
CICS Foundations
4 modules
What is CICS? Introduction and Use Cases
History, purpose, and real-world use of CICS in banking, insurance, and government mainframe environments.
Read article →CICS Architecture: Regions, Tasks, and Address Spaces
Deep dive into CICS region structure, task lifecycle, storage areas, and how CICS manages thousands of concurrent transactions.
Read article →How CICS Transaction Processing Works
From terminal input to response: the complete lifecycle of a CICS transaction including task creation, program dispatch, and termination.
Read article →CICS Resources Overview: Programs, Files, and Transactions
Overview of all major CICS resource types — programs, transactions, files, maps, queues, and terminals — and how they are defined.
Read article →CICS Programming
5 modules
CICS COBOL Programming: Your First EXEC CICS Program
Structure of a CICS COBOL program, EXEC CICS syntax, common commands, and how to compile and run your first CICS transaction.
Read article →CICS EIB: Using the Execute Interface Block in COBOL
Master CICS EIB fields: EIBTRNID, EIBCALEN, EIBAID, EIBDATE, EIBTIME, EIBRESP and how to use them in your programs.
Read article →CICS BMS Maps: Creating and Using Basic Mapping Support
Design BMS mapsets, define fields, assemble maps, and use SEND MAP and RECEIVE MAP to build interactive 3270 terminal screens.
Read article →CICS COMMAREA: Passing Data Between Programs and Transactions
How COMMAREA works, DFHCOMMAREA in COBOL, passing data across XCTL and LINK calls, and using COMMAREA for session state.
Read article →Pseudo-Conversational CICS Design: The Right Way to Build Transactions
Why pseudo-conversational design is mandatory for scalable CICS, how to implement it with COMMAREA, and anti-patterns to avoid.
Read article →CICS Commands
5 modules
CICS File Control: READ, WRITE, REWRITE, DELETE Commands
Complete guide to CICS VSAM file access — READ, WRITE, REWRITE, DELETE, and browse commands with COBOL examples.
Read article →CICS Program Control: RETURN, XCTL, LINK, and CALL
Understand the differences between RETURN, XCTL, LINK, and CALL — when to use each and the implications for task ownership and storage.
Read article →CICS SEND and RECEIVE: Screen I/O Commands Complete Guide
Master SEND MAP, RECEIVE MAP, SEND TEXT, SEND CONTROL, and RECEIVE commands for 3270 terminal and web-style CICS applications.
Read article →CICS Error Handling: RESP, HANDLE CONDITION, and ABEND Codes
Robust error handling with RESP/RESP2, HANDLE CONDITION, NOHANDLE, ABEND, and HANDLE ABEND — with complete COBOL examples.
Read article →CICS Storage Control: GETMAIN, FREEMAIN, and Memory Management
Dynamic storage allocation in CICS using GETMAIN and FREEMAIN, storage classes (USER, SHARED, TASK), and avoiding storage violations.
Read article →Queues and Communication
3 modules
CICS Temporary Storage Queues: WRITEQ TS, READQ TS, DELETEQ TS
Using CICS TS queues for inter-transaction data sharing, pagination across screens, and temporary data storage with complete examples.
Read article →CICS Transient Data Queues: WRITEQ TD, READQ TD Complete Guide
Intrapartition and extrapartition TD queues, automatic task initiation (ATI), and using TD queues for logging and batch triggers.
Read article →CICS Interval Control: START, CANCEL, DELAY, and RETRIEVE
Schedule tasks with EXEC CICS START, retrieve passed data with RETRIEVE, implement timers with DELAY, and cancel scheduled tasks.
Read article →CICS and DB2
2 modules
CICS and DB2 Integration: Threads, SYNCPOINT, and SQL in CICS
How CICS manages DB2 threads, writing DB2 SQL in CICS COBOL, SYNCPOINT vs COMMIT, and performance tuning for CICS-DB2 applications.
Read article →CICS Web Services: REST and SOAP APIs from COBOL Programs
Exposing CICS programs as web services, consuming REST/SOAP APIs from COBOL, and the CICS web support architecture.
Read article →Administration and Career
3 modules
CICS Resource Definitions: CEDA, CSD, and RDO Complete Guide
Define and manage CICS resources using CEDA online facility, batch CSD utility, and Resource Definition Online — programs, transactions, files.
Read article →CICS Monitoring and Performance Tuning
CICS statistics, monitoring tools, performance tuning principles, task wait analysis, and common CICS performance problems and fixes.
Read article →50 CICS Interview Questions and Answers (2026)
Top 50 CICS interview questions covering architecture, programming, BMS, error handling, file control, DB2 integration, and administration.
Read article →Who Is This Course For?
Designed for every stage of the mainframe development career
Freshers
No mainframe experience? Start with CICS Foundations to understand what CICS is, why it exists, and how transactions work on IBM Z.
Junior Developers
Already writing COBOL? Level up with EXEC CICS commands, BMS maps, COMMAREA patterns, and robust error handling.
Experienced Professionals
Deepen expertise with DB2 integration, web services, performance tuning, administration, and interview preparation for senior roles.
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Start Learning CICS Today
CICS skills are in high demand. Banks, insurers, and government agencies are actively recruiting mainframe developers. Start Module 1 now — it is completely free.
Start Module 1: Introduction to CICS →