The more conveniently sized 5¼-inch disks were introduced in 1976, and became almost universal on dedicated word processing systems and personal computers. It was introduced into the market in an 8-inch (20 cm) format in 1971. In 1967, at an IBM facility in San Jose, California, work began on a drive that led to the world's first floppy disk and disk drive. Floppy disks were an almost universal data format from the 1970s into the 1990s, used for primary data storage as well as for backup and data transfers between computers. It is read and written using a floppy disk drive (FDD). That's a lot of questions but the way the FDS works is cleary not as straightforward as I imagined.8-inch, 5¼-inch, and 3½-inch floppy disksĪ floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium encased in a rectangular plastic carrier. I assume the data must fit some location in the CPU address space which the FDS can access, where though? How are the games really loaded then? Is the FDS sending the data as the disk is being read, or is it first loaded into an internal buffer before being sent? I guess the BIOS contains the files selcetion and games' loading routines ontop of the fancy Mario and Luigi animation.ĭoes the cart adapter map PRG and CHR ROM to the FDS internal BIOS ROM or it is loaded into the adapter's RAM like an actual game? I'd like to fully understand what happens when the FDS is turned on before updating the diagram. Is there anything other than a mapper chip inside?Īccording to wikipedia, the 8K BIOS is in the 2C33 and each disk contains 2 * 56K of data, is that correct? Okay, I guess Additional Hardware sounds about right. Since you're writing the address ranges where things are mapped to, maybe it would be a good idea to do that with the FDS memories too, and include the boot ROM. You should probably add some arrows there, and make the FDS expansion hardware solid and properly labeled, but this is the general idea. Prom: $8000-$FFFF usually, but not always, $6000-$7FFF may also be prom for the different mappersĬxram:$2000-$2FFF or just $2800-$2FFF for the different banking methods As far as I know, the NES/FC platform is totally unique in this regard, I know of no other retro console/computer has only ROM, RAM or if there's a combination of two the ROM is only in the computer, such as the C64 where the character set is in ROM. It's really interesting how each one of those has its benefits and drawbacks compared to the other. About half the game library has one, and the other half the other. Since NES-related terminology is almost always controversial and vague, because of termonology used by Nintendo and various reverse-engineer and emulators are different, partially overlapping and partially disagreeing, I could be wrong.Īnd the CHR-ROM label should really be CHR-ROM or CHR-RAM. At least when refering to terminology printed on Nintendo-made PCBs. As far as I know WRAM is a term used for optional extra RAM on the cartridge typically at $6000-$7fff. The WRAM label in the console is probably incorrect, it should simply read RAM.
The format never really caught on for anything besides Nintendo's FDS on a greater scale, and Quick Disk drives for computers are quite rare and obscure. The Mitsumi Quick Disk format were to serve like a middle ground alternative to the slow but cheap cassette tapes and fast but expensive floppy disks, but it was probably too unreliable to become popular. Piracy was probably mostly a problem in Hong Kong, Taiwan and other Asian countries. And FDS disks wasn't as cheap as they where supposed to be, because the drive needed lots of maintenance which supposedly lowered the profit for third-party developers. I also believe that what killed the FDS is the fact that ROM cartridges became cheaper and more advanced, making almost every advantage of FDS disks obsolete, just like Bregalad said.
There is a BIOS ROM which is somehow booted from instead of the PRG-RAM.
The FDS RAM Adapter is just a cartridge expansion device, and technically no different from any other cartridges from the Famicom's point of view.
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