Where are interrupt file for timers on the chip

Hey
I have the UNO, And i was looking for the library file that set up the timer and the interrupt for the UNO.
I need to change them to my liking..
Can some please tell me where the timer setup are including the interrupts for the timers.

.../hardware/arduino/cores/arduino/wiring.c

Note that by default only timer0 is set up to generate an interrupt (for use by millis() and associated functions.)

Thanks alot just wondering

interrupt function(parameters )

that the syntax for this chip..

Or is it ISR

What do you write in front the function to tell it to be a interrupt.
beside setting interrupt and stuff on the chip and timers..

SIGNAL(TIMER0_OVF_vect)
{
  // ISR function.
}

That's actually a macro around a bunch of standard-like stuff for non-standard parts of a C implementation (attribute stuff). More than you ever wanted to know: ??avr-libc: <avr/interrupt.h>: Interrupts

Ok thanks....
Also just wondering could these libraries be used together as in will they have conflicts on the timers they are using just wondering?

timerone library (Arduino Playground - Timer1)

newsoftserial library (NewSoftSerial | Arduiniana)

also i actually don't want to use timerone library i want to use servo.h library. But i need to put a flag in one the interrupts that it makes so i can call a function ever 2 seconds.
I notice the timerone library allows this but i also have to do more programming with it to set my servo.

So will i be able to use the libraries together..