Mylar disk; this is a very different design from that of a hard drive, where the
heads float on a cushion of air a few microns above the surface of the disk.
The motor spins the disk at a fairly lethargic 300 RPM (compared to 4,200 for
a typical laptop hard drive and 5,400 or 7,200 in a desktop machine). The
heads move in and out according to instructions from a controller on the
motherboard; the controller consults an index (called the FATor File Attribute
Table) that exists on the floppy disk itself to find out what is located where.The ferric oxide coating includes Teflon or other super-slippery compound to
reduce friction, but the fact is that the contact of the read/write head with
the disk itself will eventually grind away the oxide. Add to that the fact that a
floppy disk drive is more or less open to the elements — the cover over the
disk is not air tight, and the opening to the drive is a rather insignificant
spring-loaded flap.The bottom line: Floppy disks do not last forever and should not be used
over and over again to make copies of essential data. And floppy disk drives
are prone to mechanical failure because of the entry of dirt or because the
internal read/write heads can become knocked out of alignment. (If a floppy
drive’s heads are misaligned, it may be possible to continue using the drive,
but disks made using that particular device may not be readable on another
machine with heads aligned properly, or misaligned in a different direction.)Chapter 8: Floppy Drives: Relics and Memories 143
My museum pieces
Yes, I am aware that there were some earlier
and even more cumbersome arrangements for
storage. The very first IBM PCs and machines
from some other makers including Radio Shack,
used audio cassette recorders to hold data.
Another design, from Toshiba, used tiny micro-
cassettes. Not only were they painfully slow, but
they were not random access devices. If the file
you wanted was stored at the end of the tape,
you needed to fast forward all the way to that
point to find it.
But we all sure thought those early machines
were the bee’s knees. I bought one of each new
toy (the original IBM PC, which has the equiva-
lent processing power of one of today’s digital
watches, listed for something like $5,000). It did,
though, launch me on my writing career. I’ve
produced more than 175 books since the birth
of the PC, every one of them on a computer, and
many of them were written in full or in part on a
laptop perched on the seatback tray of an air-
liner, on my lap on a commuter train, on the
table of the Nantucket ferry, and in hotel rooms.