8086 has 20-bit address space with segmentation. However the
meaning of segmentation in 8086 is slightly different from
what we have learned in the class. There are four segmentation
registers CS, DS, ES and SS each having
16-bit length. Displacement (i. e. length of) each segment is
limited to 16-bit (64K) not a variable length. The effective address
is given by 
.