The ISA standard has been around for years, and it is still considered useful (although slow). If you just bought a new system with PCI architecture, you're in no danger of suddenly waking up with an antiquated computer on your desktop.

But changes are coming.

The PCI data bus is already proving to be a bottleneck for Pentium processors working with video conferencing and video playback.

AGP (the Accelerated Graphics Port ) and PCI Express is the newest development in the data bus marketplace. The AGP standard will significantly improve performance between the CPU, internal RAM memory and the graphics card. PCI Express promises to top out over AGP.

A major data bus making improvements every day is the Universal Serial Bus (USB), which is used for external connections to devices like keyboards and pointing devices, cameras, and portable storage devices. As USB becomes a simple, standard method for connecting external devices to a computer, all those cumbersome serial and parallel ports will be permanently tossed aside.

Even SCSI buses are facing future competition. They are extremely fast, but are often difficult to configure when multiple devices are daisy-chained.

Firewire looks like the future standard bus for external devices that require a high-speed connection to the computer. Some refer to firewire as "home electronics meets the home PC." It's still relatively expensive, but it won't stay that way.