Wasn't Sony, But Nearly As OldOne birthday around '85, I got a Walkman not long after they came out. It was a Panasonic brand and one of the first they sold. It took 4 AA batteries and could play one tape front and back before running out of juice. I smile as I remember listening to the Top Gun soundtrack and having to sneak batteries. Of course, I got caught and had an allowance docked, but I loved that soundtrack.
Years later, I replaced it with an Aiwa model which had a integrated speaker in the door. I used that a lot, but I still had the old Panasonic in my possession until 2000.