Lab Activity 4 (Subtract 2 numbers using two variables) using Assembly

.model small

.data

    message1 db 10, 13, "1st Number: $"
    message2 db 10, 13, "2nd Number: $"
    message3 db 10, 13, "Difference = $"
    line db 10, 13, "-------------$"
    num1 db ?
    num2 db ?

.code

main proc far

   mov ax, @data
   mov ds, ax

   mov num1, 5      ; store 5 in 'num1' variable
   mov num2, 4      ; store 4 in 'num2' variable

   lea dx, message1 ; print 'message1' variable
   mov ah, 09h
   int 21h

   mov ah, 2        ; print 'num1' variable
   mov dl, num1     ; move 'num1' to dl
   add dl, 48       ; add 48 to dl to make it decimal
   int 21h

   lea dx, message2 ; print 'message2' variable
   mov ah, 09h
   int 21h

   mov ah, 2        ; print 'num2' variable
   mov dl, num2     ; mov 'num2' to dl
   add dl, 48       ; add 48 to dl to make it decimal
   int 21h

   lea dx, line     ; print 'line' variable
   mov ah, 09h
   int 21h

   lea dx, message3 ; print 'message3' variable
   mov ah, 09h
   int 21h

   mov ah, 2
   mov dl, num1     ; move 'num1' to dl
   sub dl, num2     ; subtract 'num2' from dl
   add dl, 48       ; add 48 to dl to make it decimal
   int 21h

   mov ah, 4ch      ; end program
   int 21h


endp

end main