CICS-BMS

CICS-BMS (Basic Mapping Support) is a powerful feature of IBM's CICS (Customer Information Control System) that enables developers to create interactive and user-friendly input/output screens for mainframe applications.

Introduction

CICS-BMS provides a set of macros that programmers can use to define screen layouts, data entry fields, and functional keys. With CICS-BMS, developers can create multi-format screens that support both standard and custom functions, including data validation, error handling, and language translation.

Benefits

Using CICS-BMS brings several advantages for developers and end-users, including:

• Improved user experience: CICS-BMS screens are easy to use and navigate, with clear prompts and intuitive layouts.
• Simplified data entry: Input fields can be predefined with default values, editing rules, and data type formatting, reducing the risk of input errors.
• Faster application development: CICS-BMS macros allow developers to create consistent and reusable screen templates, reducing coding time and promoting standardization.
• Increased flexibility: CICS-BMS supports a wide range of data types and input/output options, enabling developers to adapt to changing business requirements.
• Better performance: CICS-BMS screens are optimized for efficient processing, minimizing system overhead and improving response times.

Components

CICS-BMS consists of three main components:

1. The mapset: A mapset is a collection of one or more CICS-BMS map definitions that define the screen layouts and field attributes. Each mapset can contain up to 255 maps, which can be referenced by application programs.

2. The map: A map defines the visual appearance of a screen, including the size, placement, and formatting of input/output fields, as well as any associated messages or prompts. Maps are defined using CICS-BMS macros.

3. The program: A CICS-BMS program reads and writes data to and from the map-based screens. Each program is linked to a specific mapset and can reference one or more maps within the set.

Example

Here is an example of a simple CICS-BMS program:

IDCAMS JOB(TESTJOB),CLASS=A,MSGCLASS=H

    EXEC CICS
        MAP 'MYMAP' 
        MAPSET 'MYMAPSET'
        END-EXEC

    EXEC CICS
        RECEIVE MAP('MYMAP')
            INTO(&MYDATA)
        END-EXEC

    EXEC CICS
        SEND MAP('MYMAP') 
            MAPSET('MYMAPSET') 
            ERASE
        END-EXEC

    EXEC CICS
        RETURN
        END-EXEC

In this example, the program reads data from a map named 'MYMAP' defined in a mapset named 'MYMAPSET'. The RECEIVE macro stores the input data into the &MYDATA variable. The SEND macro displays the map on the screen with no data. The RETURN macro ends the program.

Conclusion

CICS-BMS is a powerful tool for creating user-friendly and efficient mainframe applications. By simplifying screen design and optimizing data processing, CICS-BMS helps developers deliver high-quality software that meets end-user needs.