• AND destination, source
Can be used to clear(0) specific destination.
Ex: b AND 1 = b b AND 0 = 0
• OR destination, source
Can be used to set(1) specific destination.
Ex: b OR 0 = b b OR 1 = 1
• XOR destination, source
Can be used to complement(opposite) specific destination.
Ex: b XOR 0 = b b XOR 1 = ~b

NOT destination
Performs one’s complement (opposite) on destination.
TEST destination, source
Performs AND operation but does not change the destination contents.

Enter an ascii digit, convert it to a number then display the ascii of it in a new line.
org 100h
MOV AH, 1
INT 21H ;a function to input a ascii number from user
AND AL,0FH ;converting to a number
MOV BL,AL
MOV AH,9
LEA DX,NEWL
INT 21H ;printing a newline
MOV AH,2
MOV DL,BL
INT 21H ;printing the converted number in ascii code ret
NEWL DB 0DH,0AH,"$"

MOV number 5 in BL register and display it as an output.
org 100h
MOV BL,5 ;assign 5 to BL
OR BL,30H ;convert it to an ascii character
;so it can be printed as 5
MOV AH,2
MOV DL,BL
INT 21H ;print the number ret

• Clear AX
MOV AX, 0 or
SUB AX, AX or
XOR AX,AX
• Clear MEM
MOV MEM,0

• SHL destination, numberOfShifts
₋ Shifts the bits in destination to the left.
₋ numberOfShifts must be a direct value or a value in CL register.
₋ Inserts 0 to the rightmost bit.
₋ Loses the leftmost bit and adds to CF.
₋ Every left shift is a multiplication by 2
• SHR destination, numberOfShifts
₋ Shifts the bits in destination to the right.
₋ numberOfShifts must be a direct value or a value in CL register.
₋ Inserts 0 to the leftmost bit.
₋ Loses the rightmost bit and adds to CF.
₋ Every right shift is a division by 2

Multiply 8 by 8 and divide 65 by 4.
org 100h
MOV BL,8
MOV CL,3
SHL BL,CL
MOV BH,65
MOV CL,2
SHR BH,CL ret

• ROL destination, numberOfRotations
₋ Shifts the bits in destination to the left.
₋ numberOfShifts must be a direct value or a value in CL register.
₋ The leftmost bit is inserted in the rightmost bit.
₋ Adds to CF.
• ROR destination, numberOfRotations
₋ Shifts the bits in destination to the right.
₋ numberOfShifts must be a direct value or a value in CL register.
₋ The rightmost bit is inserted in the leftmost bit.
₋ Adds to CF.

Assign 55 to BX register then count the number of 1 bits and display it on screen.
org 100h
MOV BX,55
XOR DX, DX
MOV CX, 16
TOP:
ROL BX, 1
JNC NEXT
INC DX
NEXT:
LOOP TOP
OR DX,30H
MOV AH,2
INT 21H ret
; AX counts bits
; loop counter
; CF = bit rotated out
; 0 bit
; 1bit, increment total
; loop until done

Input a binary number then display it in a newline.
org 100h
XOR BX,BX ; CLEAR BX
MOV AH,1
INT 21H ; Input character
WHILE_:
CMP AL, 0DH ; CR?
JE END_WHILE ; YES, DONE
AND AL, 0FH ; CONVERT TO BINARY VALUE
SHL BX,1 ; MAKE ROOM FOR NEW VALUE
OR BL,AL ; PUT VALUE IN BX
INT 21H ; READ A CHARACTER
JMP WHILE_ ; LOOP BACK
END_WHILE:

mov ah,9 lea dx,newl int 21h
MOV CX,16
MOV AH,2
TOP_:
ROL BX,1 ;content in BX
JC display_one ; print bit ‘1’
MOV DL,"0" ; else Print bit ‘0’
JMP display display_one:
MOV DL,"1"
Display:
INT 21H ; Print bit either ‘0’ or ‘1’
LOOP TOP_ ; LOOP BACK ret newl db 0ah,0dh,"$"

Let the user enter 2 numbers 4 and 5 then display the sum of them.
org 100h
;prepare to read first number
MOV AH,1
INT 21H
;save the number in other register
MOV BL,AL
;convert the number to its decimal value
AND BL,0FH
;display addition symbol
MOV AH,2
MOV DL,2BH
INT 21H
;prepare to read second number
MOV AH,1
INT 21H
;convert the number to its decimal value
AND AL,0FH

;add the two numbers
ADD BL,AL
;convert the number so it would be printed as its symbol
OR BL,30H
;display a newline that is saved in a variable
MOV AH,9
LEA DX,NWL
INT 21H
;display the result
MOV AH,2
MOV DL,BL
INT 21H ret
NWL DB 0DH,0AH,"$"