install_timer - Man Page

#include <allegro.h>

int install_timer();

Installs the Allegro timer interrupt handler. You must do this before  installing any user timer routines, and also before displaying a mouse  pointer, playing FLI animations or MIDI music, and using any of the GUI  routines.

Returns zero on success, or a negative number on failure (but you may decide not to check the return value as this function is very unlikely to fail).

remove_timer(3), install_int(3)