（1）assume cs:code,ds:data,ss:stack
data segment 
        dw 0123h,0456h,0789h,0abch,0defh,0fedh,0cbah,0987h
data ends
stack segment
        dw 0,0,0,0,0,0,0,0
stack ends

code segment

start : mov ax,stack
        mov ss,ax
        mov sp,16
        mov ax,data
        mov ds,ax
        push ds:[0]
        push ds:[2]
        pop  ds:[2]
        pop ...