The next step in hard-drive bus evolution, and a break from the classic ATA legacy, is something called "serial ATA." http://www.serialata.org/. In a way analogous to what's happening with PCI Express, serial ATA replaces complicated parallel circuitry with a much simpler--but faster--serial design using just four conductors instead of 80. It's a spec that should initially deliver a theoretical maximum of around 150 Mbytes per second and ramp to 600 Mbytes per second in the next five years or so.

The first fully productized serial ATA products hit the market early this year (for example, see the Seagate Barracuda ATA V drive http://www.seagate.com/cda/ products/discsales/personal/family/0,1085,564,00.html). But, as with any first versions, there are some problems. For instance, one authoritative review of early serial ATA drives and controllers http://www.tomshardware.com/ storage/20030204/ shows that serial ATA technology isn't yet faster than top-of-the-line, high-speed, conventional ATA drives. However, even the very first mass-market serial ATA drive was notable for being quieter and cooler-running than its classic ATA counterparts, and there seems to be no doubt that drive and controller speeds will climb as new designs emerge and the technology matures.

Floppy Drives
Floppy drives have been a part of PCs from day one. The original IBM PC could optionally be equipped with two single-sided, low-density 5.25-inch floppies that each held 360 Kbytes of data. Over the years, floppies became two-sided, their data density increased, the overall size shrank, and they ultimately became the hard-shelled (and thus no-longer "floppy") 3.5-inch, 1.44-Mbyte media in common use today. But the floppy drive has nearly reached the end of its useful life.

With today's large drives, floppies are a joke as a backup medium; in fact, with today's large file sizes, it's not uncommon for floppies to be unable to hold even a single complete file. Instead, USB-based key-chain- or pen-style "flash drives" (http://www.google.com/ search?q=usb+flash+drive), really just a memory chip with some USB input/output circuitry, have become enormously popular for the simple "sneaker-net" file transfers that used to be handled by floppies.

There are perhaps only two remaining serious uses for floppies: One is for booting to DOS or Linux for low-level work on a PC. There's still some utility in this, although most current PCs can boot from a specially formatted CD http://www.google.com/ search?q=boot+cd. A boot CD can do everything a boot floppy can (except accept new data) and can hold vastly more software for setting up an operating system, performing diagnostics, or otherwise working on a PC at a low level.

The other major remaining use for a floppy drive is to access old data and files archived on floppies. This sounds more important than it really is, because floppies are ephemeral--they self-demagnetize over time, and they physically degrade as their plasticizers and chemical binders decay. Floppy life is self-limiting: After a while, archived floppies become unreadable anyway, eliminating the need for drives to read them (see Is Your Data Disappearing?).

As a result, all the major PC makers are beginning to offer floppy-free desktop units, often with a modest price rebate ($5 or so) as an incentive for buyers to accept the no-floppy option. It's slow going--only a fraction of buyers opt for the floppy-free versions of desktop PCs--but that will increase with time, just as it already has in the significantly floppy-free laptop market. It's mainly a matter of customers getting used to the idea of not having a floppy and getting more used to alternatives such as USB flash drives and boot CDs.

What's Here, What's Ahead
Clearly, the move to legacy-free design is well under way, and, piece by piece, step by step, we're moving toward the day when we'll see PCs using only fully modern, state-of-the-art high-speed components and architectures.

Some vendors are content to move with the market and let the evolution happen at its own pace. For example, Micron PC's Kelly Sasso said that legacy-free design is "really a nonissue for us at this point in time. It isn't an area that we are focused on."