assume cs:code

data segment
       db   'conversation'
data ends

code segment

start:
             mov ax,data
             mov ds,ax
             mov si,0
             mov cx,12
             call capital
             mov ax,4c00h
             int 21h

capital:
            and byte ptr [si],11011111b
            inc
 
 si
            loop capital
            ret

code ends
end start