MOV AX, 19
ADD AX,  7 ; AX <- AX + 7 = 26

NEG AX ;  AX <- -AX = -26 = 0FFE6h




MOV AX,0FFFEh ; 65534 ; Unsigned 
ADD AX,3

MOV AX,0FFFEh  ; -2 ; Signed 
ADD AX,3

; CPU sets flags for both cases (signed and unsigned)



MOV BX,6
SUB BX,7

INC BX