Famicom Disk System:
The Family Computer Disk System, Famirî Konpyûta Disuku Shisutemu?, FDS) was released on February 21, 1986 by Nintendo as a peripheral for the Family Computer ("Famicom") console in Japan. It was a unit that used proprietary floppy disks for data storage. It was announced, but never released, for the North American Nintendo Entertainment System. Through its entire production span, 1986-2003, 4.5 million units were sold.
The device was connected to the Famicom deck by plugging a modified cartridge known as the RAM Adapter into the system's cartridge port, which attached via a supplied cable to the disk drive. The RAM adapter contained 32 kilobytes of RAM for temporary program storage, 8 kilobytes of RAM for tile and sprite data storage, and an ASIC known as the 2C33. The ASIC acted as a disk controller for the floppy drive, and also included additional sound hardware featuring primitive FM synthesis capabilities. The floppy disks used were double-sided, with a capacity of 64 kilobytes per side. Many games spanned both sides of a disk, requiring the user to switch sides at some point during gameplay. A few games used two full disks (four sides). The Famicom Disk System was capable of running on six C-cell batteries or the supplied AC adapter. The battery option was included due to the likelihood of a standard set of AC plugs already being occupied by a Famicom and a television.
In 1986, the disks' 128K of storage space was quite appealing. The rewritable aspect of the disks also opened up interesting possibilities; games such as The Legend of Zelda (the first FDS game), Metroid, and Kid Icarus were released to the FDS with a save feature. Many of these titles were subsequently ported to cartridge format and released for the NES a year or two later, with saving implemented with password resume or battery-backed memory.
FDS Hardware versions:
Sharp released the Twin Famicom, Tsuin Famikon?), a composite console of both Famicom and Disk System under license.
The FDS disks were somewhat proprietary 2.8" × 3" 64K-per-side double-sided floppy. These "Disk Cards," as Nintendo called them, were a slight modification of Mitsumi's "Quick Disk" 2.8" square disk format which was used in a handful of Japanese computers and various synthesizer keyboards, along with a few word processors. Some of the QuickDisk drives even made it into devices in Europe and North America, though they were somewhat rare. Mitsumi already had close relations with Nintendo, as it manufactured the Famicom and NES consoles, and possibly other Nintendo hardware.
Nintendo's flagship mascots Mario and brother Luigi make an appearance in the FDS's BIOS. After turning on the system, a "battle" between the two characters would begin over the color scheme of the Nintendo sign and screen border, until a disk is inserted into the FDS.
Within a year of its release, piracy of the FDS disks became rampant via use of slightly modified QuickDisks and different disk copying techniques. Hacker publications such as Backup Technique (which later became Game Labo, still published today) and Famicom Kaizō Manual showed the plans to make various devices to copy the disks along with very simple plans to convert QuickDisks to FDS disks. At least a couple issues of Backup Technique even advertised products like the Dubbing Boy and the Dubbing Boy II for copying the disks, which were commercialized versions of some of the do-it-yourself projects that the publications wrote articles on. To thwart this piracy, Nintendo changed one of the ICs in the drive to a newer version and made slight modifications to some of the traces on the other PCB within the drive. Techniques were quickly published to build modification boards to circumvent these measures. Certain software techniques were used by some programmers to thwart the copying of their disks, but even these were circumvented by certain unlicensed FDS programs like Disk Hacker (versions include 1.1, 1.2, 1.3, and II), Kosodate Gokko, Copy Master, Disk Keeper, and others, which facilitated the copying of disks.
FDS Reliability Issues:
While the Disk System was years ahead of its time in terms of a disc-format game console, the system and games both have reliability issues. The drive belt in the drive is a proprietary size, and standard floppy drive belts are too big. In addition, no drive in the U.S. uses that size belt, so replacement belts must be obtained from Japan. Until 2004, Japanese residents were able to send their systems to Nintendo directly for repairs/belt replacements, but Nintendo of America and the PAL regions do not service them. The old belts have a habit of breaking or even melting on occasion.
In addition, the disks themselves must be tested and verified to work on both sides, as the FDS disks’ construction can allow dirt to get into the disk, or even for the disk to demagnetize over time. Even one bad sector on a disc will render it unplayable. In an effort to save money on production, Nintendo opted to not use disk shutters (a feature seen on 3.5” floppy disks) to keep dirt out, instead opting to include wax paper sleeves as with the older 5.25” floppies. The only exception to this were certain games that were special released on blue discs (which did have shutters).
Also, error messages received when attempting to load a disk are unusually simple, to the point where it is difficult to know what the exact problem is. Most in-game error messages during loading are often displayed as 'Err. ##', with ## being the designated number for the type of error message --- the most common ones are Err. 02 (the Disk System's batteries being low on power or with no batteries put in altogether), Err. 07 (Side A and B reversed when trying to load the disk), and Err. 27 ('Disk trouble', usually involving the disk surface itself). However, the error messages themselves consist of little explanation (Err. 27, for example, only give the accompanying message 'Disk trouble') and in most cases within gameplay itself, such as Zelda 2, the error message is not given at all, with only the number code shown.
Square Co., Ltd. had a branch at one point called 'Disk Original Group', a software label that published Disk System titles from Japanese PC software companies. The venture was largely a failure and almost pushed a pre-Final Fantasy Square into bankruptcy. (Final Fantasy was to be released for the FDS, but a disagreement over Nintendo's copyright policies caused Square to change its position and release the game as a cartridge.)
Nintendo released a disk version of Super Mario Bros. in addition to the cartridge version. The Western-market Super Mario Bros. 2 originated from a disk-only game called Yume Kōjō: Doki Doki Panic.
Nintendo would hold game score contests, and the mascot was called Disk-kun (Mr. Disk in English). Some of the prizes to these contests included 2 gold prize disks, one for the game Golf US course, and one for Golf Japan course (Not to be confused with the title simply called Golf). These two gold disks had metal shutters on them, like the aforementioned blue disks. Other prizes were a stationary set, and a gold cartridge version of the NES/Famicom Punch-Out!! titles. In the gold version of Punch-Out!!, the final boss was Super Macho Man, before Nintendo used Mike Tyson and Mr. Dream instead in later NES versions.