osx man page for install_int

install_int(3alleg4)						  Allegro manual					      install_int(3alleg4)

NAME
       install_int - Installs a user timer handler. Allegro game programming library.

SYNOPSIS
       #include <allegro.h>

       int install_int(void (*proc)(), int speed);

DESCRIPTION
       Installs  a  user  timer  handler,  with  the  speed  given  as	the  number  of  milliseconds  between	ticks.	This  is the same thing as
       install_int_ex(proc, MSEC_TO_TIMER(speed)). If you call this routine without having first installed the timer module, install_timer()  will
       be called automatically. Calling again this routine with the same timer handler as parameter allows you to adjust its speed.

RETURN VALUE
       Returns zero on success, or a negative number if there is no room to add a new user timer.

SEE ALSO
       install_timer(3alleg4),	remove_int(3alleg4),  install_int_ex(3alleg4),	install_param_int(3alleg4),  exscn3d(3alleg4),	exswitch(3alleg4),
       extimer(3alleg4), exzbuf(3alleg4)

Allegro 							   version 4.4.2					      install_int(3alleg4)