4.2 Conversion bin to dec + logic operations bit-to-bit

;Write a program that acquires two variables of type byte opA and opB in binary format by keyboard ('0' and '1' sequence) and writes the result of logic operation bitwise into a variable of type byte ris.
;Logic expression bit-to-bit is:
;C = NOT(A AND (NOT(B))) OR (A XOR B).

;IMPLEMENTATION
;Acquisition binary values:
;-It's need conversion of ASCII character read by keyboard
;-User types binary values (ex.:“00011100”) separated by ENTER
;Logic operations on byte carried out with specific instructions

DIM EQU 8     ;Dimension of every binary number... 8bit
.MODEL small
.STACK
.DATA
opa DB ?
opb DB ?
ris DB ?
.CODE
.STARTUP
MOV ah,1
XOR bx,bx
MOV CX,DIM
;The first cycle concerns first variable opa
ciclo1: int 21h    ;In input I can insert only 0 or 1
        SUB AL,'0'
        DEC CX
        SHL AL,CL  ;SHL and OR instructions convert my binary number to decimal number. SHL does: AL*2^CL. In a cycle is, for example: 1*2^7+0*2^6+1*2^5+etc... that is the conversion from binary to decimal
        OR BL,AL   ;L'OR sums in BL the values in decimal that corresponds at the bit at 1
        CMP CX,0
        JNZ ciclo1
INT 21h
MOV opa,BL  ;puts the converted number (to decimal) in opa
xor BX,BX
MOV CX,DIM
ciclo2: int 21h       ;This 2° cycle concerns opb
        SUB AL,'0'
        DEC CX
        SHL AL,CL
        OR BL,AL
        CMP CX,0
        JNZ ciclo2

MOV opb,BL   ;put the decimal result in opb
;Below there are the required logic operations by the text
MOV al,opb
not al
and al,opa
not al
mov ah,opa
xor ah,opb
or al,ah
mov ris,al

.exit
END

;Then, since the text is unclear,
;the text asks to write in input into two
;variables 2 binary numbers, and convert them to decimal
;and then to apply that logic operations that asks
;at the end; so that logic operations are done
;on operands with decimal value, because then the assembler
;considers however the binary numbers since the logic operations
;work bit-to-bit