CODE SEGMENT
; Set DS register
MOV AX, DATA ; boiler plate code to set the DS register so that the
MOV DS, AX ; program can access the data segment.
; read first digit from keyboard
MOV AH, 08
INT 21H
MOV BL, AL
SUB BL, '0'
MUL BL, 10H
; read second digit from keyboard
MOV AH, 08H
INT 21H
MOV DL, AL
SUB DL, '0'
; DL = 9 AND BL = 30
SUM BL, DL
; Now BL store 39
CODE ENDS.
Note: Boilerplate code is the code which is present less or more in the similar form in each assembly language program.