In the olden days of computers, they were as good at communicating as the people on earth after the Tower of Babel incident. Not only did none of the scant networking protocols interact well, but the floppy disks were sometimes completely different sizes. That is, when there were disks; there were some systems based on cartridges, like video game systems. In fact, on an Ataric, not only could you play pong, but you could balance your finances via spreadsheet.