Ever since Apple introduced its iMac series of computers, featuring a
conspicuous lack of floppy drive, people have been speculating an early
retirement for the floppy disk. The floppy's capacity is nowadays relatively
small, its speed ain't so racy, and its design just isn't hip anymore. Floppies,
the PC-user's memory-mules of choice since 1981, have finally reached their
best-before date.
If Apple prognosticated the demise of the floppy, then it's heralding its
latest successor, too. The zip disk is around the same size as your average
3.5inch floppy, but it holds almost 100 times as much data, is speedier to
access, and more stable to use. That said, the zip disk -- as well as the
larger-format diskettes that preceded the 3.5inch floppy -- operates on the same
principle as the floppy disk. A brief explanation of those principles follows
here.
At the core of the floppy disk is something called the media, which consists
of a plastic disk coated in a chemical compound that is sensitive to magnetic
impulses - basically, rust. The information you save or download from floppies
is converted to magnetic signals. When you insert a floppy into your computer's
disk drive, a mechanism retracts the metal sheath that protects the media,
so that it becomes exposed to the drive's read-write heads. These heads register
magnetic impulses from the disk, or else encode them onto the disk. In order to
relay data from the disk to the computer, the magnetic impulses are converted to
electrical currents that the computer -- if not its human operator --
understands.
In order for read-write heads to glean information from diskettes, those
diskettes must rotate. The computerized muscle that effects this task is called
the spindle motor. It's connected to something called the hub clamp, which grips
the disk's hub. The hub looks like a small, circular metal disk on the bottom of
the floppy, and it represents the only exposed portion of the media. When it
spins around, the rest of the media spins around, and the read-write heads are
able to exchange signals with the surface of the media. Data is stored in
strings around the media, much like the grooves in a record.
One of the reasons floppies are not the most reliable means of storing
information is that the read-write heads must come into physical contact with
the media, which causes wear and tear. Another reason floppies are unstable is
the mechanism that drives the read-write heads across their surface. In order to
find a particular strand of information, the read-write heads are guided by the
stepper motor which moves them towards the inside or outside of the disk. Zip
disks, by contrast, feature a much smoother read-write motion, with less jarring
and potential corruption of data.
When you first insert an unused disk into your computer's A-drive, the PC
will ask you to format that disk. This process divides the media into tracks and
sectors. Tracks are the rings that circle the media, and sectors are
equal-length segments of those rings. The determine how information will be
stored on the floppy. By contrast, a zip disk requires on formatting at first
use; only if the disk is travelling between PCs and Mac computers will you be
prompted to reformat it.
If all these details on floppies are too hard to understand, you might
consult the simpler, more useful guide of John Kinsella, the Manager of Computer
Systems at the University of California at Davis. If his manual, at here,
doesn't bring a smile to your face, then you really are hard to
please.