pcbeep.c File Reference

#include <freeldr.h>

Include dependency graph for pcbeep.c:

Go to the source code of this file.

Macros
#define	CLOCK_TICK_RATE   1193182

Functions
static VOID	Sound (USHORT Frequency)
VOID	PcBeep (VOID)

Macro Definition Documentation

CLOCK_TICK_RATE

#define CLOCK_TICK_RATE   1193182

Definition at line 13 of file pcbeep.c.

Function Documentation

PcBeep()

VOID PcBeep

(

VOID

)

Definition at line 34 of file pcbeep.c.

{
    Sound(700);
    StallExecutionProcessor(100000);
    Sound(0);
}

Referenced by MachInit().

Sound()

static VOID Sound ( USHORT  Frequency )

static

Definition at line 17 of file pcbeep.c.

{
    USHORT Scale;

    if (Frequency == 0)
    {
        WRITE_PORT_UCHAR((PUCHAR)0x61, READ_PORT_UCHAR((PUCHAR)0x61) & ~3);
        return;
    }

    Scale = CLOCK_TICK_RATE / Frequency;
    WRITE_PORT_UCHAR((PUCHAR)0x43, 0xB6);
    WRITE_PORT_UCHAR((PUCHAR)0x42, Scale & 0xFF);
    WRITE_PORT_UCHAR((PUCHAR)0x42, Scale >> 8);
    WRITE_PORT_UCHAR((PUCHAR)0x61, READ_PORT_UCHAR((PUCHAR)0x61) | 3);
}

Referenced by PcBeep().