40 lines
920 B
C
40 lines
920 B
C
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/*
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KEYSTAPL.C - This example shows how to get the keyboard
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status under 386|DOS-Extender by looking at the ROM
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BIOS keyboard status byte in low memory.
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Compile & Link: wcl386 /l=pharlap keystapl
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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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void main()
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{
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/* We require a far pointer to use selector
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for 1st megabyte */
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char far *ptr;
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/* Set pointer to segmented address of the first
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status byte */
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ptr = MK_FP( 0x34, 0x417 );
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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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