Question:
How do I temporarily turn off range checking for a block of code, 
then turn it back on if it was originally enabled ?
Answer:
You can do this in code by using "IFOPT" and "DEFINE".
type
 PSomeArray = ^TSomeArray;
 TSomeArray = array[0..0] of integer;
procedure TForm1.Button1Click(Sender: TObject);
var
 p : PSomeArray;
 i : integer;
begin
{$IFOPT R+}
 {$DEFINE CKRANGE}
 {$R-}
{$ENDIF}
 GetMem(p, sizeof(integer) * 200);
 
 try
 for i := 1 to 200 do
 p[i] := i;
 finally
 FreeMem(p, sizeof(integer) * 200);
 end;
{$IFDEF CKRANGE}
 {$UNDEF CKRANGE}
 {$R+}
{$ENDIF}
end;