Question

Write an example of an assembly language comment using MARS.

Answer 1

#this program is to store 2 numbers sum in assembly language

.data
A:          .word       # store first integer A
B:          .word       #storing 2nd Integer B
S:          .word       #this s integer is used to store A and B
Prompt1:    .asciiz "Input A: "
Prompt2:    .asciiz "input B: "
Result:     .asciiz "A+B = "

.text
main:
    #Prompt for integers A
    li $v0, 4          # Load instruction for printing the string
    la $a0, Prompt1    # Load Prompt1 into $a0
    syscall

    #Read first integer
    li $v0, 5      # Read first integer A
    la $t0, A    
    syscall

    #Store first integer A into the memory
    move    $t0, $v0  
    sw $t0, A     
  

    ##Prompt for integers B
    li $v0, 4          # Load instruction for printing the string
    la $a0, Prompt2    # Load prompt2 into $a0
    syscall

    #Read second integer
    li $v0, 5      # Read second integer
    la $t1, B      # $t0 = A
    syscall

    #Store second integer into memory
    move    $t1, $v0    # Move contents in $v0 to $t0
    sw $t1, B      # A = value at $t0
  

    #Add the two variables A and B and store it in S
    la $t2, S      # $t2 = S
    add     $t2, $t0, $t1   # $t2 = $t0 + $t1
    sw $t2, S      # S = value at $t2

    #Display the Result prompt
    la $a0, Result # Loads Output label to be printed
    li $v0, 4      # Sysycall to print string
    syscall

    #Display the sum
    lw $a0, S      # $a0 = value at S
    li $v0, 1      # Syscall to print integer
    syscall

    #exit out of the program
    li $v0, 10     # Loading exit code to $v0
    syscall