5. Problems Related to Segmentation

• Segmentation often caused grief for programmers who tried to access large data structures:

  • Since an offset cannot exceed 16 bits, you cannot increment beyond 64k.

  • Instead, program must watch out for a 64k boundary and then play games with the segment register.

• This nightmare was originally created to support CP/M-80 programs ported from 8080 chip to 8086.

  • Successful short-term thinking;

  • Catastrophically bad long-term thinking that resulted in never-ending Windows 9x problems!