Mastering Mainframe CICS: From Beginner to Expert

Explore cics basics to advanced topics, including online vs batch, architecture, symbolic and physical maps, tasks and transactions, multithreading, menu-based programs, file maintenance, and exception handling with databases.

Explore how CICS enables online transaction processing for real-time results, moving beyond batch processing with instant responses used by Fortune 500 banks and other industries.

Explore the features of CICS, including online real-time transactions, batch processing, and integrated DBRS and data communication facilities, while understanding its built-in file management and multitasking capabilities.

Compare batch and online processing in mainframe environments, highlighting input methods, instant updates, concurrency, turnaround times, and typical job schedules.

Explore batch processing and online processing on mainframes. Learn how batch updates master files, stores data sequentially, prints reports, and how online processing handles terminal transactions and instant updates.

Explore the advantages of CICS, including real-time data validation, instant results, and concurrent multi-user access, alongside disadvantages like higher resource use and costs and the batch versus online processing decision.

Explore the five major components of CICS, including data communication, data link, application programming service, data handling, and system monitoring, and how they interface with terminals, operating system, and databases.

Learn about four commonly used cics programs: data entry, inquiry, file maintenance, and menu-driven programs, each guiding an operator to input, view, or update master file records.

Define a CICS transaction as a unit of work that executes atomically, identified by a four-digit ID. Distinguish user-defined from system-defined transactions with examples like ACMD and TBR.

Explore system defined transactions in CICS, including online program definition, opening files and maps, and debugging with DEA and Semak, using the execute master terminal (CMT) and CSF sign-off.

Explore multitasking in mainframe CICS, where a task represents a transaction execution with a user and data, and multiple tasks run concurrently using same or different programs (insert, update, delete).

Understand how multitasking lets the operating system run multiple programs concurrently and allocate resources; multithreading shares a single program among users at different terminals.

Learn the modes of communication in CICS, including the conversation mode where the system waits for terminal responses and resources are restored, illustrated with hotel and waiter analogies.

Explore pseudo conversation programming by handing control to another task to optimize resource utilization in real-time systems, with transactions initiated by user input and terminal messages.

Explore the architecture of CICS control programs and their tables, including the file control program, copy and program control programs, terminal control, system initialization, and the transaction initiation flow.

Explore how a terminal-entered transaction in Nova is recognized, validated by control tables, located via BCT and PBT, and then loaded and started with file and resource checks.

Explore how a CICS screen works, resembling an IBM 3270 terminal. Display up to 1920 characters, with 24 rows and 8 columns, and enable function keys for program access.

Explore basic mapping in CICS with BMS: design online screens, map user options to subsequent screens, and link front-end pages to back-end programs using function keys.

Learn how maps and mapsets define screens in CICS. A map is a screen; a mapset is a collection of maps, defined with map fields, naming conventions, and MDA/MDF macros.

Explore the map programming structure in mainframe CICS, defining maps with columns and labels, configuring symbolic and physical maps, and using parameters, input variables, and display rules.

Explore the screen hierarchy in map design for Mainframe CICS, from screen to fields, distinguishing enterable and protected data, and setting initial values.

Develop and visualize a simple CICS map with employee id and employee details by defining fields, mapping data, and distinguishing symbolic and physical maps, including a copybook structure.

Compare the physical map and symbolic map in CICS, showing how physical map drives screen input and output while the symbolic map serves as a data copy for application logic.

Discover the two methods to display a map: manual display and display through an application program, with practical explanations and theoretical understanding, and the next video will cover online region.

Connect to the online region, define and install a new map, and verify it via system tables and the command center map for real-time viewing.

Explore how a customer information control system uses a command level language, including cobol program structure with call and exec, to display messages, receive input, transfer control, and initiate transactions.

Learn how an application program sends a map through CICS to drive a transaction and control screen flow, illustrated by a debit card entry and receipt.

Master the steps to receive a map in CICS and display a simple message on the screen, using a sample program that demonstrates the map’s basic syntax.

Explore a sample CICS program that sends and receives a map to display a message. Compile, register the program and its transaction in online tables, then install and run it.

Add date and time handling to a mainframe CICS program by defining time variables, using timestamp and absolute time, and updating the map before logging and executing the transaction.

Identify and use CEMT functions to manage resources by creating a new copy of a CMT program, linking transactions, inquiring about the transaction program, and performing open and close operations.

Classify programs by conversation and transaction styles in CICS, including screen messaging, send and receive data flows, and the use of written statements for data storage.

Explore the two types of written return statements in CICS, where a completed user transaction is reinstated and control returns to the system.

Explore file handling concepts, comparing random and sequential access, and learn how key-based random access enables reading, writing, and deleting data, with notes on using databases.

Learn to read files in mainframe CICS using sequential reads and key-based reads with partial and full keys, and handle exceptions like file not open or not found.

Explore a CICS file handling write option, showing how to specify record length, key, and filename, and note exceptions like duplicate record, file not found, and not open.

Learn how to rewrite and delete records in mainframe cics, handle update logic and common exceptions, and delete by partial keys using a generic count of deleted records.

Master sequential file handling in CICS. Navigate with read next and read previous, reset to reposition, and use browse and write fields with conditions like greater than or equal to.

Master CICS error handling by managing hardware and logical exceptions, such as file not found or divide by zero. Use handle condition and response codes to keep programs running smoothly.

Explore program control operations in cics, focusing on xctl, which passes control from one program to another and expects return, uses a communication area, and does not hold resources.

Transfer control from one program to another using link, then automatically return to the main program, a technique used for validating complex business functions and menu driven programs.

Understand TDQ and TSQ in CICS, including writing to and reading from queues, the role of item numbers, sequential vs random access, and the need to destroy records after deletion.