Why Famicom Disk is spelled with a "k"

[turbo D]

Hello true believers!,

Please allow turbo D to waste one of your braincells with his amazing breakthrough! The spelling disk is used to identify magnetic media while the spelling disc is used to identify optical media. So there you have it, that is your explanation.

[Jedi Master Baiter]

You're forgetting one thing: who asked this question?

[JC]

I did. Thanks, turbo D!

[xyzzy32]

Thank you for the clarification. I've wasted countless hours mapping out plans for suicide upon seeing this abomination and disgrace to the English language.

[UglyJoe]

But the magnetic media inside of the disk is, in fact, a circular disc!  Does not compute!

[turbo D]

Hmmm, so confusion still exists, eh? Perhaps I should clarify further.

Magnetic disks use magnetic particles to store items such as data, instructions, and information on a disk's surface. Depending on how the magnetic particles are aligned, they represent either a 0 bit or a 1 bit. A track is a narrow recording band that forms a full circle on the surface of the disk. The disk's storage locations consist of pie-shaped sections, which break the tracks into small arcs called sectors. Sectors are grouped into clusters. A cluster is the smallest unit of disk space that stores data and information. Each cluster, also called an allocation unit, consists of two to eight sectors (the number varies depending on the OS). Each cluster holds data from only one file. One file, however, can span many clusters.

An optical disc is a type of storage media that consists of a flat, round portable disc made of metal, plastic, and lacquer that is written and read by a laser. Optical discs store items by using microscopic pits (indentations) and lands (flat areas) that are in the middle layer of the disc. A high-powered laser light creates the pits. A lower-powered laser light reads items from the disc by reflecting light through the bottom of the disc, which usually is either solid gold or silver in color. The reflected light is converted into a series of bits the computer can process. A land causes light to reflect, which is read as binary digit 1. Pits absorb the light; this absence of light is read as binary digit 0.

[L___E___T]

also, disc is obviously designating a circular object, the sun, an LP record etc.   'disk' is short for the french word diskette which is something different.  Diskettes are the floppy disks we know and love, of which the disk system uses too.  A disk has a circular disk inside, but it's not an actual disc istelf, hence the word diskette.  Diskette refers directly to floppy disks, it's unambiguous unlike the word disc.  So, the disk systems is spelled with a K because of course it uses floppy disks.

Same as Turbo's explanation in essence, but a little extra info on why floppy disks needed their own word in the first place.

[turbo D]

Perhaps the floppy disk got its name in contrast to its inflexible father the hard disk drive. The HDD in your computer is a disk. The HDD, or hard disk drive, contains one or more inflexible, circular platters that magnetically store data, instructions, and information. The HDD platter is made of aluminum, glass, or ceramic and is coated with an alloy material that allows items to be recorded magnetically on its surface. The coating usually is three millionths of an inch thick. The HDD saves data in the process described previously for magnetic disks.

[L___E___T]

I forgot about that!

[Lorfarius]

I think the universe just exploded.

[manuel]

No, the universe is still there.
I checked. 

But I felt a disturbance in the Schwartz Force...

[Trium Shockwave]

It was a little confusing when I first got my hands on a 3.5" floppy disk. It didn't flop like the big ones on my old PC Jr. or the Apple II's I'd used at school, therefore I assumed this was a hard disk. After confusing my uncle for a while, he finally set me straight.

Also, fun fact, since the platters in a hard drive are sometimes glass, they can shatter. Someone once brought us an iPod that sounded like a helicopter. He'd been having issues, so decided to follow some Internet advice to whack it against the edge of a table. Opened it up, and, well, yeah. That was some bad advice.