Microsoft KB Archive/43091

From BetaArchive Wiki
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.

COBOL Version 3.0 Call X“B7” Can Hang Using Function 5

PSS ID Number: Q43091 Article last modified on 04-20-1993

3.00 3.00a MS-DOS

The information in this article applies to:
- Microsoft COBOL for MS-DOS, versions 3.0 and 3.0a

Summary: Using the special subprogram CALL X“B7” in Microsoft COBOL Versions 3.0 or 3.0a may hang the system if you use Function 5 (clear attributes from the screen) on a blank screen. To prevent the hanging, use this function only when the screen is not blank.

More Information: Executing the following code will hang the machine, only if the DISPLAY statements are removed.

Code Example: WORKING-STORAGE SECTION. 01 FUN PIC 99 COMP-X VALUE 05. 01 PARM. 03 D-LENGTH PIC 9(4) COMP-X VALUE 1600. 03 START-POS PIC 9(4) COMP-X VALUE 241. 03 BUF-START PIC 9(4) COMP-X VALUE 1. 01 BUFF1 PIC X(2000). 01 BUFF2 PIC X(2000). PROCEDURE DIVISION. DISPLAY “*************” AT 0101 WITH HIGHLIGHT. DISPLAY “*************” AT 1010 WITH HIGHLIGHT. DISPLAY “*************” AT 2020 WITH HIGHLIGHT. CALL X“B7” USING FUN, PARM, BUFF1. MOVE 04 TO FUN. CALL X“B7” USING FUN ,PARM, BUFF2. STOP RUN.

Additional reference words: 3.00 3.00a Copyright Microsoft Corporation 1993.