If you're a video game of a certain vintage, then you'll definitely recall everybody (and their grandma) referring to video game consoles back in the late 1980s and early 1990s as "Nintendos."
As in "Hey, where's John, Grandma?", "He's inside playing on the Nintendo." – where upon finding John he was actually playing the Sega Genesis.
In fact, the success of the Nintendo Entertainment System and its successor the Super Nintendo Entertainment system had ensured that not only were the physical systems themselves practically ubiquitous in American households, but the name , too, had become a generic term for game consoles in general — much like people say Kleenex in place of tissue or Coke in place of soda.
To prevent damage to their trademark and dilution of their powerful branding, Ni Nowadays, aggressively promoting the phrase "game console", ran ads — like the one here — reminding people that Nintendo should be used as a generic term for game systems, and otherwise moved to protect the reputation of their brand. The strategy worked and short of a well-meaning grandma here or there, you'd be hard pressed to find anyone referring to game consoles as "Nintendos" these days.