INF: Turning the SCROLL LOCK Key On

ID Number: Q40359

5.x 6.00 6.00a 6.00ax 7.00

MS-DOS

Summary:

The following code illustrates how to turn the SCROLL LOCK key on in

your program. Note: This code is only for use with MS-DOS. Running it

with OS/2 will cause a protection violation. Use the OS/2 FAPI

function KbdSetStatus() to set the status of shift flags when writing

programs that will run with OS/2 or be bound to run with both MS-DOS

and OS/2.

Sample Code

-----------

/* Compile options needed: none

*/

#include <stdio.h>

main()

{

/* Get the address of the keyboard status byte */

char far *kbdstat = (char far *) 0x00000417;

char scrollmask = 0x10;

/* OR *kbdstat with scrollmask to set bit 4 in the

keyboard status byte to 1 */

*kbdstat = *kbdstat | scrollmask;

}

Additional information on keyboard status can be found in the Peter

Norton "Programmer's Guide to the IBM PC and PS/2." The above

information also applies to QuickC.

Additional reference words: 5.00 5.10 6.00 6.00a 6.00ax 5.0 5.1 6.0

6.0a 6.0ax 7.00 7.0