# Test interrupt-driven i/o.
	.text
main:
	addi $sp,$sp,-4
	sw	$s0,0($sp)
	la	$t7,initTransmitter
	jalr $t7
	la	$s0,alphabet
loop:
	lb	$a0,0($s0)
	beq	$a0,$0,done
	la	$t7,putchar
	jalr $t7
	addi $s0,$s0,1
	j	loop

done:
	j	done

	.data
alphabet:
	.asciiz	"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"

	.ktext
initTransmitter:
	mfc0 $t0,$12		# Set global interrupt-enable bits.
	ori	$t0,0xFF01
	mtc0 $t0,$12
	lui	$t0,0xFFFF
	sw	$0,12($t0)		# Send a null character to the transmitter.
	jr	$ra

putchar:
	sb	$a0,outputBuffer	# Store character into the output buffer.
	addi $t3,$0,1
	sb	$t3,outputBufferIsFull
	lui	$t0,0xFFFF		# Turn on transmitter (display) interrupts.
	lw	$t1,8($t0)
	ori	$t1,$t1,2
	sw	$t1,8($t0)
	jr	$ra