Here is the code from class.

.data

grades: .word 60, 70, 80
size:	.word 3
endl:	.asciiz  "\n"	
sum:	.asciiz "The sum is "
	
.text

main:
	lw 	$t1, size($zero)	# the array size
	move	$t0, $zero		# index, increment by 1
	move 	$t2, $zero		# offset into array
	move	$t4, $zero		# sum
top:	beq	$t0, $t1, out

	lw	$t3, grades($t2)	# a = array]i]
	add	$t4, $t4, $t3		# sum += a
		
	move	$a0, $t3		# cout << a << endl;
	li	$v0, 1	
	SYSCALL
	
	li	$v0, 4
	la	$a0, endl
	SYSCALL
	
	addi	$t0, $t0, 1		# i++
	addi	$t2, $t2, 4		# increment offset
	
	b	top

	
out:	

	la	$a0, sum
	li	$v0, 4
	SYSCALL
	
	move	$a0, $t4
	li	$v0, 1
	SYSCALL
	
	li	$v0, 4
	la	$a0, endl
	SYSCALL
	
	li	$v0, 10
	SYSCALL

Well Sort of. I didn't write it down, so this is what I remember.
I made a mistake on the assignment and hooked the Adder up backwards (led and ground should be switched)
- And if you only want one output from the ACC you can do that.
Logical Operations
- Section 2.6 discusses logical operations.
  - shift left and shift right.
  - Look up the format.
```
a:	.word  255
  
.text
main:	
	lw 	$t0, a
	sll 	$t1, $t0, 3
	srl 	$t2, $t1, 2 
```
  - 255 is ff₁₆ or 1111 1111₂
  - shifted to the left by 3 will be 111 1111 1000₂ or 7f8₁₆
  - Shift 7f8₁₆ two to the right you get (1 1111 11102 or 1fe16
- There are a number of bit wise logical operations
  - and, andi, or, ori, not
  - Look at these.