Parameter Directives 

     Turbo Pascal's Parameter Directives enable you to pass information
     to the compiler at compile time.  The four Parameter Directives are:

  {$I FileName}                   Includes external files when compiling
  {$L FileName}                   Link the file being compiled with FileName
  {$M StackSize,HeapMin,HeapMax}  Specifies memory allocation parameters
  {$O UnitName}                   Transforms a Unit into an overlay