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C/C++ Users Group Library 1996 July
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C-C++ Users Group Library July 1996.iso
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v_02_01
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1990-12-01
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921b
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42 lines
#include "uclock.h"
#include "sound.h"
static int usec_timeout(uclock_t start, uclock_t finish, uclock_t usecs)
{
if (usecs >= (finish - start))
return 0;
else return 1;
}
void dosound(int freq)
{
unsigned i;
outp(C8253, SETIMER);
i = (unsigned)freq%256;
outp(F8253, i);
i = (unsigned)freq/256;
outp(F8253, i);
}
void mktone(int freq, int update, unsigned delay)
{
uclock_t start;
if (0 == freq)
{
soundoff();
return;
}
dosound(freq);
if (update != UPDATE)
soundon();
if (delay == 0)
return;
start = usec_clock();
while (!usec_timeout(start, usec_clock(), 1000L * (long)delay))
;
if (update == TOGGLE)
soundoff();
}