This is a Famicom (NES) with a “Disk System” attached to it. The Disk System was an add on for the Famicom that could use re-writable disk like the one pictured below.
This was a big innovation,because you could fit more data, save the progress of games, and it was cheaper to produce. Lots of games that came on cartridges in North America were actually originally Disk System games, like Metroid and Zelda. To help people understand it easier, Nintendo made a comic book to explain it. I found this on the internet recently.
It’s all about three kids and their adventures learning about Disk System. Here a page of the actual comic translated in English.
If you want to read the whole thing go to NFG Games. They’ve translated the whole thing for your viewing pleasure.