#################################################################
# If you use interrupts, unlike the polling, you do not need to 
# wait a specific amount of time to type a character.
#######################################################
	.data
msg:	.asciiz "\n Elapsed time = "
	.text

main:
	li $a3, 0xffff0000 # base address of I/O
	li $s1, 2          
	sw $s1, 0($a3)     #enable keyboard interrupt
	li $s1, 0x0000ffff #mask to enable all interrupts
	mtc0 $s1,$12       #store enable bits in status register
	li $s1, 0

countdown:
        li $s0,2500000
waitloop:
	addi $s0, $s0,-1
	bnez $s0,waitloop 
	bnez $s0,waitloop
	addi $s1, $s1,5
	li $v0,4
	la $a0,msg
	syscall

	move $a0,$s1
	li $v0,1
	syscall

	addi $t0, $s1, -60
	bnez $t0, countdown
	li $v0, 10
	syscall