anchor.diff:  // Original C implementation by David Jones, available here:
   //     https://github.com/davidejones/winsnake
   
  -// NB THe code isn't yet idiomatic Dart, but it demonstrates some
  -// useful concepts, including pointer arithmetic and use of virtual
  -// memory in Win32.
  +// Note: This code isn't very idiomatic for Dart, since it's an almost direct
  +// translation of the C code. Nevertheless, it demonstrates some useful
  +// concepts, including pointer arithmetic and use of virtual memory in Win32.
   
   import 'dart:ffi';
   import 'dart:math' show Random;
  
positive.code: 
    // init snake
    snakePoints.clear();
    final p1 = Point();
    p1.x = 3;
    p1.y = 0;
    snakePoints.add(p1);
  
    final p2 = Point();
    p2.x = 2;
    p2.y = 0;
    snakePoints.add(p2);
  
    final p3 = Point();
    p3.x = 1;
    p3.y = 0;
    snakePoints.add(p3);
  
    final p4 = Point();
    p4.x = 0;
    p4.y = 0;
    snakePoints.add(p4);
  
    for (var i = 0; i < snakePoints.length; i++) {
  
negative.code:   // play sound
    Beep(750, 100);
    // increase speed and increase snake
    final newPoint = Point()
      ..x = snakePoints[snakePoints.length - 1].x
      ..y = snakePoints[snakePoints.length - 1].y;
    snakePoints.add(newPoint);
  
    KillTimer(hWnd, IDT_TIMER1);
  