What does this x86 assembly language code with IO ports 0x61 and 0x20 do? -

What does this x86 assembly language code with IO ports 0x61 and 0x20 do? -

this code:

push ax in al, 0x61 or al, 0x80 ; 10000000b out 0x61, al , al, 0x7f ; 01111111b out 0x61, al mov al, 0x20 out 0x20, al pop ax

what do? know connected timer interrupt. what's on 0x61 , 0x20?

there in al, 0x60 instruction close by.

ports 0x60 , 0x61 talk keyboard controller in pc. port 0x60 contains key pressed, , 0x61 has status bits.

toggling high bit of status port signals have gotten key , want next one.

port 0x20 interrupt controller, acknowledge have processed interrupt.

assembly x86 interrupt