Microsoft KB Archive/21093

Sending Control Characters to the Screen

PSS ID Number: Q21093 Article last modified on 11-16-1992

2.00 2.10 2.20 3.00 | 3.00 MS-DOS | OS/2

Summary: When attempting to send control characters to the screen through a WORKING-STORAGE variable, the BIOS removes the preliminary escape character in an attempt to perform the special function. As a result, all control characters that follow do not make sense. The BIOS then disregards the rest of the sequence. Therefore, control sequences must not be embedded in data that is DISPLAYed. If control codes are embedded in screen data, the results will be unpredictable. To send control characters, use the SCREEN SECTION (for screen control sequences) or CALL an assembly-language subroutine that invokes the escape sequence.

Copyright Microsoft Corporation 1992.