I/O with syscalls in SPIM

Reading an integer

        li      $v0, 5
	syscall
	move    $s0, $v0

Result is stored in $s0.

Printing an integer

        li      $v0, 1
	move    $a0, $s0
	syscall

Reading a string

                .data
string:         .byte   0:20
		.text
		li      $v0, 8
		la      $a0, string
		li      $a1, 20
		syscall

Result is stored in the memory pointed to by 'string'.
The result includes all characters until a newline is encountered or until 19 characters have been read. (The final character is used for null termination, like in C.)

Printing a string

		.data
string:		.asciiz "Hello World"
		.text
                li      $v0, 4
		la      $a0, string
		syscall