1.1 Convert lowercase to uppercase characters

;Given three variables of type byte corresponding to three lowercase alphabetic characters (ASCII)
;–Var1 = ‘a’
;–Var2 = ‘s’
;–Var3 = ‘m’
;Write a program that prints on the screen the three characters converted to uppercase

DIM EQU 32  ;32 because if I have a lowercase character and I subtract 32, into ASCII code, I get corresponding uppercase character
.MODEL small
.STACK
.DATA
Var1 DB 'a'
Var2 DB 's'
Var3 DB 'm'
.CODE
.STARTUP
MOV DL,Var1
SUB DL,DIM
MOV AH,2
INT 21H  ;In AH there is value 2, so here I say "PRINT the value in DL"
MOV DL,Var2
SUB DL,DIM
INT 21H
MOV DL,Var3
SUB DL,DIM
INT 21H
.EXIT
END