# Loops, Strings, Traversing Arrays   
# This program bumps up each letter of a string by one.
#  There is no wrap-around after z.

	.text
	.globl __start
__start:
	la $a0, prompt
	li $v0, 4
	syscall
	li $v0, 8		# read string
	li $a1, 20		# max length
	la $a0, str		# address of string
	syscall
	move $t0 , $a0
loop:
	lb $t1, ($t0)
	addiu $t1, $t1, 1	# $t1 stores each character
	sb $t1, ($t0)
	addiu $t0, $t0, 1
	lb $t2, ($t0)
	bnez $t2, loop		# Assumes string is not empty.  Note this will crash on empty string

	li $v0, 4		# address is already in $a0
	syscall
	li $v0, 10
	syscall

	.data
str: 	.space 20
prompt: .asciiz "Enter String:"