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beep-1.2.2/beep.c  view on Meta::CPAN

#include <linux/kd.h>

/* I don't know where this number comes from, I admit that freely.  A 
   wonderful human named Raine M. Ekman used it in a program that played
   a tune at the console, and apparently, it's how the kernel likes its
   sound requests to be phrased.  If you see Raine, thank him for me.  
   
   June 28, email from Peter Tirsek (peter at tirsek dot com):
   
   This number represents the fixed frequency of the original PC XT's
   timer chip (the 8254 AFAIR), which is approximately 1.193 MHz. This
   number is divided with the desired frequency to obtain a counter value,
   that is subsequently fed into the timer chip, tied to the PC speaker.
   The chip decreases this counter at every tick (1.193 MHz) and when it
   reaches zero, it toggles the state of the speaker (on/off, or in/out),
   resets the counter to the original value, and starts over. The end
   result of this is a tone at approximately the desired frequency. :)
*/
#ifndef CLOCK_TICK_RATE
#define CLOCK_TICK_RATE 1193180
#endif

#define VERSION_STRING "beep-1.2.2"

lib/Audio/Beep/Linux/PP.pm  view on Meta::CPAN

Follows what you can read there:

 I don't know where this number comes from, I admit that freely.  A 
 wonderful human named Raine M. Ekman used it in a program that played
 a tune at the console, and apparently, it's how the kernel likes its
 sound requests to be phrased.  If you see Raine, thank him for me.  

 June 28, email from Peter Tirsek (peter at tirsek dot com):

 This number represents the fixed frequency of the original PC XT's
 timer chip (the 8254 AFAIR), which is approximately 1.193 MHz. This
 number is divided with the desired frequency to obtain a counter value,
 that is subsequently fed into the timer chip, tied to the PC speaker.
 The chip decreases this counter at every tick (1.193 MHz) and when it
 reaches zero, it toggles the state of the speaker (on/off, or in/out),
 resets the counter to the original value, and starts over. The end
 result of this is a tone at approximately the desired frequency. :)

=head1 BUGS

None known.

=head1 COPYRIGHT