Editing Famicom Disk System (section)

==Technology==
The device is connected to the Famicom console by plugging its [[RAM]] Adapter cartridge into the system's cartridge port, and attaching that cartridge's cable to the disk drive. The RAM Adapter contains 32&nbsp;[[kilobyte]]s (KB) of RAM for temporarily caching program data from disk, 8&nbsp;KB of RAM for tile and [[Sprite (computer graphics)|sprite]] data storage,<ref name="Revisiting the FDS">{{cite web | title=Revisiting the Famicom Disk System: mass storage on console in 1986 | first=John | last=Linneman | work=Eurogamer | date=July 27, 2019 | url=https://www.eurogamer.net/articles/digitalfoundry-2019-retro-revisiting-famicom-disk-system | access-date=July 29, 2019}}</ref> and an [[Application-specific integrated circuit|ASIC]] named the 2C33. The ASIC acts as a [[disk controller]], plus single-cycle [[table-lookup synthesis|wavetable-lookup synthesizer]] sound hardware. Finally, embedded in the 2C33 is an 8KB BIOS ROM.  The Disk Cards used are double-sided, with a total capacity of 112&nbsp;KB per disk. Many games span both sides of a disk and a few span multiple disks, requiring the user to switch at some point during gameplay. The Disk System is capable of running on six C-cell [[Battery (electricity)|batteries]] or the supplied AC adapter. Batteries usually last five months with daily game play. The inclusion of a battery option is due to the likelihood of a standard set of AC plugs already being occupied by a Famicom and a television.

The Disk System's Disk Cards are somewhat proprietary 71&nbsp;mm × 76&nbsp;mm (2.8 × 3 in) 56K-per-side double-sided floppy. They are a slight modification of [[Mitsumi]]'s [[History_of_the_floppy_disk#Mitsumi's_%22Quick_Disk%22_3-inch_floppies|Quick Disk]] 71&nbsp;mm 2.8 in square disk format which is used in a handful of Japanese computers and various synthesizer keyboards, along with a few word processors. QuickDisk drives are in a few devices in Europe and North America. Mitsumi already had close relations with Nintendo, as it manufactured the Famicom and [[Nintendo Entertainment System|NES]] consoles, and possibly other Nintendo hardware.

Modifications to the standard Quick Disk format include the "NINTENDO" moulding along the bottom of each Disk Card. In addition to branding the disk, this acts as a rudimentary form of [[copy protection]] - a device inside the drive bay contains raised protrusions which fit into their recessed counterparts, ostensibly ensuring that only official disks are used.<ref name="Nintendo's early DRM">{{Cite web|url=https://kotaku.com/nintendos-early-drm-was-simple-and-didnt-work-30784483|title=Nintendo's Early DRM Was Simple (And Didn't Work)|last=Plunkett|first=Luke|website=Kotaku|date=June 13, 2012 |language=en-US|access-date=April 25, 2019}}</ref> If a disk without these recessed areas is inserted, the protrusions cannot raise, and the system will not allow the game to be loaded. This was combined with technical measures in the way data was stored on the disk to prevent users from physically swapping copied disk media into an official shell.<ref name="Nintendo's early DRM" /> However, both of these measures were defeated by pirate game distributors; in particular, special disks with cutouts alongside simple devices to modify standard Quick Disks were produced to defeat the physical hardware check, enabling rampant piracy. An advertisement containing a guide for a simple modification to a Quick Disk to allow its use with a Famicom Disk System was printed in at least one magazine.