Floppy disk

A floppy disk is a human portable data storage device, using a magnetized disc inside of a plastic casing to store data in binary form. They are not in fact floppy, but are generally rigid.

Chip Chase can tear one in half with his bare hands.

One 5¼" floppy disk can hold the entire personality and memories of Optimus Prime.

From Teletraan I: The Transformers Wiki, a Wikia wiki.