where is hardware timer interrupt?

Question

this is Exceptions and Interrupts table(which I understand as IDT) from the \"Intel Architecture Software Developer Manual\"

Answer 1

The interrupt vector for a hardware timer interupt is IRQ 0 = INT 32, as it's an external interrupt.

0-19 are non-maskable interrupts, 20-31 should be reserved by Intel, 32-127 are the external interrupts (IRQ). The hardware time needs to be connected as IRQ 0, so the vector number should be 32 here.