用汇编编写DOS下的内存驻留程序(3)：中断矢量

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   ;Display a ":"
   ;----------------------------------------------------------------------------
   dcolon  proc    near
    mov     al,'':''
    call    dchar
    ret
   dcolon  endp
   ;----------------------------------------------------------------------------
   ;Display a " "
   ;----------------------------------------------------------------------------
   dspace  proc    near
    mov     al,'' ''
    call    dchar
    ret
   dspace  endp
   ;----------------------------------------------------------------------------
   ;Display a Carriage Return/Line Feed
   ;----------------------------------------------------------------------------
   dcrlf   proc    near
    mov     al,0dh
    call    dchar
    mov     al,0ah
    call    dchar
    ret
   dcrlf   endp
   ;----------------------------------------------------------------------------
   ;Display the character contained in AL
   ;----------------------------------------------------------------------------
   dchar   proc    near
    push    ax
    push    bx
    mov     bh,1
    mov     ah,0eh
    int     10h
    pop     bx
    pop     ax
    ret
   dchar   endp
   ;----------------------------------------------------------------------------
   ;Data define
   ;----------------------------------------------------------------------------
   hextab  db      ''0123456789ABCDEF'',0
   disptab db      05h                     ;Print screen
    dw      v05
    db      19h                     ;Bootstrap loader
    dw      v19                    
    db      08h        &