When Was the First Hard Drive, According to Dina Zielinski?

On TED Talks Daily, Dina Zielinski says IBM released the first hard drive in 1956. She describes it being loaded for shipping in front of a small audience. It held about as much as one MP3 and weighed more than a ton, at roughly 10,000 dollars a megabyte. She reaches that machine by stepping back from a 1984 TED talk in which a Sony executive explained the compact disc, and she notes that thirty years after that talk people were still discussing digital storage. Her point is that storage keeps changing because every medium eventually wears out or becomes obsolete.