In 1986, Nintendo released the Famicom Disk System (FDS) in Japan, a type of floppy drive that uses a single-sided, proprietary 5 cm (2") disk and plugs into the cartridge port. It contains RAM for the game to load into and an extra single-cycle wavetable-lookup sound chip. The disks were originally obtained from kiosks in malls and other public places where buyers could select a title and have it written to the disk. This process would cost less than cartridges and users could take the disk back to a vending booth and have it rewritten with a new game. The disks were used both for storing the game and saving progress and total capacity was 128k (64k per side).
Is there an answer to this question (If it cannot be answered, say "unanswerable"): How were the disks purchased?
buyers could select a title and have it written to the disk