Originally designed only for printers, the parallel port turned out to be an amazingly
flexible and universal interface for attaching a host of different devices to a variety of
PCs. While rather slow, the parallel port has the advantages of being (mostly) standard,
and present on virtually every PC. For this reason, it is often used for attaching
external devices such as hard disks, CD-ROM drives and tape drives, especially for PCs
that lack other expansion alternatives such as notebooks. For many years, I personally
used a parallel-port Iomega Zip drive when I was maintaining several dozen PCs that were
not networked; it was very helpful for transferring files between machines and doing
backups. The parallel port can also be used with special software to connect two PCs
together to let them share files.
Today, the role of the parallel port for storage devices is diminishing rapidly, as its
"niche" is increasingly being filled by other interfaces that offer advantages
over it. Almost all notebook PCs, for example, now come with PC Card slots and USB ports,
which offer plug-and-play operation and better performance than the parallel port. The
rise of networking has also largely obviated the need to use the parallel port for file
sharing or connecting PCs together. I do expect use of the parallel port interface to
"hang around" for many, many years, for the same reason floppy disk drives continue to be used: they are universal
and there are a lot of devices around that make use of the parallel interface. As long as
printers continue to use the parallel port as a primary means of attachment, other devices
will be available for the parallel port as well.
Next: PCMCIA (PC Card) and CardBus
