Addressing Modes
 
     Addressing Mode       Format of Address      Default Segment Register
     ---------------       -----------------      ------------------------
     Register                   register                    None
 
     Immediate                    data                      None
 
     Register Indirect            [BX]                       DS
                                  [BP]                       SS
                                  [DI]                       DS
                                  [SI]                       DS
 
     Base Relative*            label [BX]                    DS
                               label [BP]                    SS
 
     Direct Indexed*           label [DI]                    DS
                               label [SI]                    DS
 
     Base Indexed*           label [BX + SI]                 DS
                             label [BX + DI]                 DS
                             label [BP + SI]                 SS
                             label [BP + DI]                 SS
 
     String Instructions         source                     DS:SI
                              destination                   ES:DI
 
  *  Label [...] can be replaced with [displacement + ...].  Therefore,
     writing [24 + BX] would produce the address 24 + BX.
 
       Note:          Many of the string instructions use ES:DI for the
                      destination and DS:SI for the source.