40 lines
897 B
C
40 lines
897 B
C
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/*
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KEYSTAT.C - This example shows how to get the keyboard
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status under DOS/4GW by looking at the ROM BIOS
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keyboard status byte in low memory.
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Compile & Link: wcl386 /l=dos4g keystat
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*/
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#include <stdio.h>
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#include <dos.h>
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/*
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Under DOS, the keyboard status byte has a segmented
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address of 0x0040:0x0017. This corresponds to a
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linear address of 0x417.
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*/
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#define LOW_AREA 0x417
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void main()
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{
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/* Only need a near pointer in the flat model */
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char *ptr;
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/* Set pointer to linear address of the first
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status byte */
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ptr = (char *)LOW_AREA;
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/* Caps lock state is in bit 6 */
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if( *ptr & 0x40 ) {
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puts( "Caps Lock on" );
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}
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/* Num lock state is in bit 5 */
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if( *ptr & 0x20 ) {
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puts( "Num Lock on" );
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}
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/* Scroll lock state is in bit 4 */
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if( *ptr & 0x10 ) {
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puts( "Scroll Lock on" );
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}
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}
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