In:
   AX     = 0100h
   BX     = paragraphs to allocate
Out:
   if successful:
     carry flag clear
     AX     = real mode segment address
     DX     = protected mode selector for memory block
   if failed:
     carry flag set
     AX     = DOS error code
     BX     = size of largest available block

Function 000C - Set Descriptor	Table of Content	Function 0101 - Free DOS Memory Block