Saves + Synth > Passwords.
The Famicom Disk System (or the Family Computer Disk System to give its full title) released in Japan — and Japan only — on 21st February 1986. This Famicom add-on came with a wave of new games on bespoke Nintendo-branded floppy discs which had several advantages over cartridges at the time, plus one or two drawbacks. Load times from discs were an issue (then as now), and you’re far more likely to come across a non-functioning FDS disc these days than you are a Famicom cartridge.
As you can see, Nintendo added some (easily circumvented) copy protection via an indented ‘I’ and ‘N’ in the logo on its disks. Also, note FDS mascot Diskun on the left.
Read the full article on nintendolife.com