Cassette-based games were all the rage in the 80s thanks to the likes of the ZX Spectrum, Commodore 64, MSX, and Amstrad CPC 464. But did you know that Nintendo used them for their Family Computer line of consoles?
To do this, Nintendo created something called Family BASIC as part of its Family Computer consoles, exclusive to Japan. It launched in 1984 with an improved version called Family BASIC V3 releasing a year later. Family BASIC allowed users to create games in BASIC and save them onto cassette. The video above shows it in action.
Fun fact: Satoshi Tajiri (you know, that dude who created Pokémon) used Family BASIC to get better acquainted with the Famicom. That eventually led him to make his own game dev hardware and the game Quinty (aka Mendel Palace).