The Commodore 1541 is a floppy disk drive which was made by Commodore International for the Commodore 64 (C64), Commodore's most popular home computer. The best-known floppy disk drive for the C64, the 1541 is a single-sided 170-kilobyte drive for 5¼" disks. The 1541 directly followed the Commodore 1540.
The Commodore 1571 is Commodore's high-end 5¼" floppy disk drive, announced in the summer of 1985. With its double-sided drive mechanism, it has the ability to use double-sided, double-density (DS/DD) floppy disks, storing a total of 360 kB per floppy. It also implemented a "burst mode" that improved transfer speeds, helping address the very slow performance of previous Commodore drives.
A floppy disk or floppy diskette is a type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a fabric that removes dust particles from the spinning disk. Floppy disks store digital data which can be read and written when the disk is inserted into a floppy disk drive (FDD) connected to or inside a computer or other device.
The disk controller is the controller circuit which enables the CPU to communicate with a hard disk, floppy disk or other kind of disk drive. It also provides an interface between the disk drive and the bus connecting it to the rest of the system.
Disk density is a capacity designation on magnetic storage, usually floppy disks. Each designation describes a set of characteristics that can affect the areal density of a disk or the efficiency of the encoded data. Such characteristics include modulation method, track width, coercivity, and magnetic field direction.
In computer science, group coded recording or group code recording (GCR) refers to several distinct but related encoding methods for representing data on magnetic media. The first, used in 6250 bpi magnetic tape since 1973, is an error-correcting code combined with a run-length limited (RLL) encoding scheme, belonging into the group of modulation codes. The others are different mainframe hard disk as well as floppy disk encoding methods used in some microcomputers until the late 1980s. GCR is a modified form of a NRZI code, but necessarily with a higher transition density.
Modified frequency modulation (MFM) is a run-length limited (RLL) line code used to encode data on most floppy disks and some hard disk drives. It was first introduced on hard disks in 1970 with the IBM 3330 and then in floppy disk drives beginning with the IBM 53FD in 1976.
Floppy disk format and density refer to the logical and physical layout of data stored on a floppy disk. Since their introduction, there have been many popular and rare floppy disk types, densities, and formats used in computing, leading to much confusion over their differences. In the early 2000s, most floppy disk types and formats became obsolete, leaving the 3+1⁄2-inch disk, using an IBM PC compatible format of 1440 KB, as the only remaining popular format.
A floppy-disk controller (FDC) is a hardware component that directs and controls reading from and writing to a computer's floppy disk drive (FDD). It has evolved from a discrete set of components on one or more circuit boards to a special-purpose integrated circuit or a component thereof. An FDC is responsible for reading data presented from the host computer and converting it to the drive's on-disk format using one of a number of encoding schemes, like FM encoding or MFM encoding, and reading those formats and returning it to its original binary values.
The Disk II Floppy Disk Subsystem, often rendered as Disk ][, is a 5 +1⁄4-inch floppy disk drive designed by Steve Wozniak at the recommendation of Mike Markkula, and manufactured by Apple Computer, Inc. It went on sale in June 1978 at a retail price of US$495 for pre-order; it was later sold for $595 including the controller card and cable. The Disk II was designed specifically for use with the Apple II personal computer family to replace the slower cassette tape storage.
Atari 8-bit computer peripherals include floppy drives, printers, modems, and video game controllers for Atari 8-bit computers, which includes the 400/800, XL, XE, and XEGS.
A floppy disk is a disk storage medium composed of a thin and flexible magnetic storage medium encased in a rectangular plastic carrier. It is read and written using a floppy disk drive (FDD). 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.
The Macintosh External Disk Drive is the original model in a series of external 3+1⁄2-inch floppy disk drives manufactured and sold by Apple Computer exclusively for the Macintosh series of computers introduced in January 1984. Later, Apple would unify their external drives to work cross-platform between the Macintosh and Apple II product lines, dropping the name "Macintosh" from the drives. Though Apple had been producing external floppy disk drives prior to 1984, they were exclusively developed for the Apple II, III and Lisa computers using the industry standard 5+1⁄4-inch flexible disk format. The Macintosh external drives were the first to widely introduce Sony's new 3+1⁄2-inch rigid disk standard commercially and throughout their product line. Apple produced only one external 3+1⁄2-inch drive exclusively for use with the Apple II series called the Apple UniDisk 3.5.
The floppy disk is a data storage and transfer medium that was ubiquitous from the mid-1970s well into the 2000s. Besides the 3½-inch and 5¼-inch formats used in IBM PC compatible systems, or the 8-inch format that preceded them, many proprietary floppy disk formats were developed, either using a different disk design or special layout and encoding methods for the data held on the disk.
The Indus GT is a 5+1⁄4-inch floppy disk drive that was introduced by Indus Systems in 1983 for the Atari 8-bit family. It was later released for the Apple II and Commodore 64. On the Atari, it was widely regarded as the best drive of the era, with the most features, highest performance, and even best industrial design. They were known for the advertising slogan, "Turn your Atari into a Ferrari." The GT was sold until around 1987, at which point the rights were sold to Logical Design Works and reintroduced as the LDW Super 2000, sold primarily into Poland, and the CA-2001, sold into the US.
The Atari 810 is the official floppy disk drive for the Atari 400 and 800, the first two models of Atari 8-bit computers. It was released by Atari, Inc. in 1980.
The Atari 1050 is a floppy disk drive for Atari 8-bit computers released in June 1983. It is compatible with the 90 kB single-density mode of the original Atari 810 it replaced, and added a new "enhanced" or "dual density" mode that provided 130 kB. Based on a half-height Tandon mechanism, it was smaller than the 810 and matched the styling of the new 600XL and 800XL machines.
The XF551 is a 5 1/4 inch floppy disk drive produced by Atari, Inc. for the Atari 8-bit computers. Introduced in 1987, it matches the gray design language of the XE models. It was the first drive from the company with official support for double-density and double-sided floppy disks—360 kB of storage per disk—and was also the final floppy disk drive Atari produced for the 8-bit computers. The XF551 allows faster transfer speed when used in double-density mode, doubling performance.
Frequency modulation encoding, or simply FM, is a method of storing data that saw widespread use in early floppy disk drives and hard disk drives. The data is modified using differential Manchester encoding when written to allow clock recovery to address timing effects known as "jitter" seen on disk media. It was introduced on IBM mainframe drives and was almost universal among early minicomputer and microcomputer floppies. In the case of floppies, FM encoding allowed about 80 kB of data to be stored on a 5+1⁄4-inch disk.
