The Disk II Floppy Disk Subsystem, often spelled as Disk ][, was a 5¼-inch floppy disk drive designed by Steve Wozniak and manufactured by Apple Computer. It was first introduced in 1978 at a retail price of US$495 for pre-order; it was later sold for $595 including the controller card (which can control up to two drives) and cable. The Disk II was designed specifically for use with the Apple II personal computer family to replace the slower cassette tape storage and cannot be used with any Macintosh computer without an Apple IIe Card as doing so will damage the drive and/or controller.
Apple produced at least six variants of the basic 5¼-inch Disk II concept over the course of the Apple II series' lifetime: The Disk II, the Disk III, the DuoDisk, the Disk IIc, the UniDisk 5.25" and the Apple 5.25 Drive. While all of these drives look differently and they use four different connector types, they're all electronically extremely similar, can all use the same low-level disk format, and are all interchangeable with the use of simple adapters, consisting of no more than two plugs and some wires between them. Most DuoDisk drives, the Disk IIc, the UniDisk 5.25" and the AppleDisk 5.25" even use the same 19-pin D-Sub connector, so they are directly interchangeable. The only 5.25" drive Apple sold aside from the Disk II family was a 360k MFM unit made to allow Mac IIs and SEs to read PC floppy disks.
This is not the case with Apple's 3.5" drives, which use several different disk formats and several different interfaces, electronically quite dissimilar even in models using the same connector, and are not generally interchangeable.
Other articles related to "ii, iis, disk, disk ii":
... The first Apple II computers went on sale on June 10, 1977 with a MOS Technology 6502 microprocessor running at 1 MHz, 4 KB of RAM, an audio cassette interface for loading programs and storing ... The earliest Apple IIs were assembled in Silicon Valley, and later in Texas printed circuit boards were manufactured in Ireland and Singapore ... An external 5¼-inch floppy disk drive, the Disk II, attached via a controller card that plugged into one of the computer's expansion slots (usually slot 6), was used for data ...
... This table shows the pinout of the original 1979 Disk II controller and newer 1983 Uni/Duo Disk I/O controller (655-0101) ... The Disk II header pin numbering is per the Disk II controller card silkscreen and the circuit schematic given in the DOS 3.3 manual ... The Uni/Duo Disk D-19 pinout is taken from the Apple //c Reference Manual, Volume 1 ...
... An external 5¼-inch floppy disk drive, the Disk II, attached via a controller card that plugged into one of the computer's expansion slots (usually slot 6 ... The Disk II interface, created by Steve Wozniak, was regarded as an engineering masterpiece for its economy of electronic components ... While other controllers had dozens of chips for synchronizing data I/O with disk rotation, seeking the head to the appropriate track, and encoding the data into magnetic pulses, Wozniak's controller card had few chips ...
... Originally the Apple II used audio cassette tapes for program and data storage ... a third party R-F modulator) made the total cost of owning an Apple II less expensive and helped contribute to the Apple II's success ... Even after disk drives made the cassette input and output ports obsolete they were still used by enthusiasts as simple one-bit audio input-output ports ...
Famous quotes containing the word disk:
“Unloved, that beech will gather brown,
This maple burn itself away;
Unloved, the sun-flower, shining fair,
Ray round with flames her disk of seed,
And many a rose-carnation feed
With summer spice the humming air;”
—Alfred Tennyson (18091892)