Chapter 5: Further Reading -- Basic Input/Output and DISPLAY/ACCEPT Statements

Books

"Murach's Mainframe COBOL" by Mike Murach & Associates The chapters on console I/O and report generation provide clear, practical examples of DISPLAY and ACCEPT usage patterns in both batch and interactive contexts. The book's treatment of structured output lines using WORKING-STORAGE record definitions is particularly well-organized, showing the progression from simple DISPLAY statements through professionally formatted report output. The section on IBM-specific DISPLAY UPON CONSOLE behavior and its relationship to JCL SYSOUT is essential reading for mainframe programmers. Available from the publisher and major booksellers.

"Beginning COBOL for Programmers" by Michael Coughlan (Apress) This book includes an entire chapter on interactive COBOL programming with ACCEPT and DISPLAY, including the SCREEN SECTION. Written for programmers coming from other languages, it explains COBOL's I/O model without assuming mainframe background. The GnuCOBOL-focused examples are directly executable on a personal computer, making it ideal for hands-on practice with the SCREEN SECTION, colors, and cursor positioning. Published by Apress in print and digital formats.

"COBOL for the 21st Century" by Nancy Stern, Robert A. Stern, and James P. Ley The report generation chapters in this textbook provide extensive coverage of formatted output techniques, including header/detail/footer patterns, page break logic, and control break reporting. While focused on file-based output rather than console DISPLAY, the record-line construction techniques are identical and directly applicable to building formatted console output. Published by Wiley.

"Mainframe COBOL: The Complete Course" by various authors Several comprehensive COBOL courses include dedicated sections on the distinction between batch and interactive I/O patterns. These are valuable for understanding why DISPLAY/ACCEPT behave differently in JCL batch environments versus TSO interactive sessions versus CICS online programs. The coverage of ACCEPT FROM DATE/TIME/DAY-OF-WEEK with practical date-formatting examples is particularly useful. Search for comprehensive COBOL course materials at technical bookstores.

Online Resources

GnuCOBOL SCREEN SECTION Documentation The GnuCOBOL project documentation provides the most complete reference for the SCREEN SECTION, including all supported clauses (LINE, COLUMN, FOREGROUND-COLOR, BACKGROUND-COLOR, HIGHLIGHT, LOWLIGHT, UNDERLINE, REVERSE-VIDEO, BLINK, SECURE), the behavior of DISPLAY screen-name and ACCEPT screen-name, and known limitations. It also documents GnuCOBOL-specific extensions such as ACCEPT FROM COMMAND-LINE and ACCEPT FROM ARGUMENT-VALUE. Search for "GnuCOBOL Programmer's Guide" on SourceForge.

"COBOL ACCEPT and DISPLAY Tutorial" (Mainframes.com and similar sites) Several COBOL tutorial sites maintain dedicated pages on the ACCEPT and DISPLAY statements, including tables of ACCEPT FROM system-information variants, IBM-specific DISPLAY UPON destinations, and working examples of date/time retrieval with REDEFINES for component extraction. These are useful quick references when you need to look up the exact format of ACCEPT FROM TIME or the meaning of DAY-OF-WEEK values. Search for "COBOL ACCEPT FROM DATE tutorial" to find current resources.

"Interactive COBOL with GnuCOBOL" (community tutorials and blog posts) The GnuCOBOL community has produced various tutorials and blog posts demonstrating interactive terminal programs, including menu-driven applications, data entry forms with the SCREEN SECTION, and color/attribute demonstrations. These provide working code that can be compiled and run immediately, supplementing the textbook examples with additional patterns and techniques. Search for "GnuCOBOL SCREEN SECTION examples" or "interactive COBOL GnuCOBOL" to find current posts.

IBM Documentation

"Enterprise COBOL for z/OS: Language Reference" -- DISPLAY and ACCEPT Chapters (IBM publication) The Language Reference precisely defines DISPLAY and ACCEPT behavior on IBM mainframes, including the interaction between DISPLAY and the SYSOUT DD statement, the behavior of DISPLAY UPON CONSOLE as a WTO (Write-To-Operator) message, the ACCEPT FROM DATE/TIME/DAY/DAY-OF-WEEK formats, and the ACCEPT FROM ENVIRONMENT-NAME/ENVIRONMENT-VALUE mechanism. This is the authoritative source for understanding how these statements behave in z/OS batch and TSO environments. Search for publication SC27-1408 on the IBM Knowledge Center.

"CICS Application Programming Guide" (IBM publication) For programmers who will work with IBM mainframes, understanding why DISPLAY and ACCEPT are not used in CICS programs is essential. The CICS Application Programming Guide explains the Basic Mapping Support (BMS) mechanism that replaces DISPLAY/ACCEPT for terminal I/O in CICS environments. The conceptual chapter on the CICS programming model -- including pseudo-conversational design and the EXEC CICS SEND MAP / RECEIVE MAP paradigm -- provides context for how IBM mainframe interactive programs differ fundamentally from GnuCOBOL terminal programs. Search for the CICS documentation library on the IBM Knowledge Center.

"Enterprise COBOL for z/OS: Programming Guide" -- Formatting Output Chapter (IBM publication) The Programming Guide includes practical guidance on building formatted output with COBOL, including techniques for constructing report lines, using edited PICTURE clauses effectively, and the interaction between DISPLAY output and the JCL output class. The section on intrinsic functions relevant to I/O (FUNCTION CURRENT-DATE, FUNCTION NUMVAL, FUNCTION TRIM) supplements the ACCEPT FROM DATE mechanisms covered in this chapter. Search for SC27-1412 on the IBM Knowledge Center.

Standards and Historical References

ISO/IEC 1989:2014 -- Section 14: ACCEPT and DISPLAY Statements The official COBOL standard defines the portable behavior of ACCEPT and DISPLAY, including which FROM options are standard (DATE, TIME, DAY, DAY-OF-WEEK) and which are implementation-defined (ENVIRONMENT-NAME, COMMAND-LINE). The SCREEN SECTION specification in Section 8.8 defines the standard clauses and their semantics, distinguishing between what is required by the standard and what is a compiler extension. Available for purchase from ISO.

"The Evolution of COBOL I/O" (academic and industry papers) Several papers trace the evolution of COBOL's I/O model from the original 1959 specification (which focused entirely on file I/O for batch processing) through the addition of ACCEPT and DISPLAY for console communication, the SCREEN SECTION in COBOL-2002, and the modern extensions for environment variables and command-line arguments. Understanding this evolution explains why COBOL's I/O model seems unusual compared to languages designed in the interactive computing era. Search academic databases and COBOL conference proceedings for papers on COBOL I/O history.

"Human-Computer Interaction in Terminal-Based Systems" (various sources) For programmers building interactive COBOL applications with the SCREEN SECTION, understanding the principles of terminal-based user interface design improves the quality of the programs. Topics include screen layout conventions, color usage for emphasis versus information, field-level validation timing, and the unique constraints of character-mode interfaces. While not COBOL-specific, these principles directly apply to SCREEN SECTION design. Search for "text-based user interface design" or "TUI design principles" in computing literature.