2. Another chip 8259, called PIC (programable interrupt controler)
gets those signals and produce interrupts, to be exact IRQ0, every
X time. It is depend on current machine parameter. If in Linux x86
it is 100, so 8259 produces interrupt in 10000 microsec.
If all that right Linux does depend only on capability of PIC to
produce that kind of interrupt frequency, but on PIC type? I mean,
it can be any PIC chip.