Certainly many people do not know about the function of the hard disk in the PS2, many staff when commenting this are surprised.

Certainly the Game cube also has its interesting functions very little known, soon I will make a post with that content (thanks for the idea =D)

The slim had that little detail with the discs, that was caused by the flex that was inside, there came a time when it played the disc and caused that very characteristic circular scratch on the discs.

Thank you for the comment @gooddream