%TITLE "AND/OR/XOR instructions demo" IDEAL DOSSEG MODEL small STACK 256 DATASEG exitCode DB 0 ;if you want comments sourceWord DW 0ABh ; BUY the book wordMask DW 0CFh CODESEG Start: mov ax,@data mov ds,ax mov ax,[sourceWord] mov bx,ax mov cx,ax mov dx,ax and ax,[wordMask] or bx,[wordMask] xor cx,[wordMask] xor dx,dx Exit: mov ah,04Ch mov al,[exitCode] int 21h End Start