APIC 82489 datasheet

Hi all,
Does anyone have a datasheet for APIC 82489 chip? I could not find it
anywhere..
I understand that this chip is a replacement for I8259 used till now as
an interrupt controller on a PC/AT. I would like to learn more, and to play
with extra IRQs (IRQ15+) it provides.
Most modern PC chipsets support this chip am I correct?
Thanks for help.

Janusz