Factorial

.stack 100h
.model small
.data
    n dw 3
.code

main proc

    mov ax,@data
    mov ds,ax

    mov cx,n
    dec cx
    mov ax,n

    fact:
        dec n
        mul n
        loop fact

    mov ah,2
    mov dx,ax
    add dx,30h
    int 21h

    main endp
end main