top button
Flag Notify
    Connect to us
      Site Registration

Site Registration

What is a far pointer? Where we use it?

+5 votes
970 views
What is a far pointer? Where we use it?
posted Nov 9, 2013 by Mona Sharma

Share this question
Facebook Share Button Twitter Share Button LinkedIn Share Button

1 Answer

+3 votes

In large data model (compact, large, huge) the address B0008000 is acceptable because in these
model all pointers to data are 32bits long. If we use small data model(tiny, small, medium) the above address won’t work since in these model each pointer is 16bits long. If we are working in a small data model and want to access the address B0008000 then we use far pointer. Far pointer is always treated as a 32bit pointer and contains a segment address and offset address both of 16bits each. Thus the address is represented using segment : offset format B000h:8000h. For any
given memory address there are many possible far address segment : offset pair. The segment register contains the address where the segment begins and offset register contains the offset of data/code from where segment begins.

answer Nov 9, 2013 by Vikas Upadhyay
...