They truly mastered the progress bar on the Commodore 64 with a tape drive. You were told how many blocks the computer had to load and because the tape moved along at a constant speed, they counted down at a uniform rate. Once it got to zero, you knew you were only seconds away from playing your game. And the border of the screen would flash different colours as each block loaded, indicating that it was still doing something inbetween each block loading. Progress bars went downhill from there :P