High-Speed 1394 Train Still at the Station

Christopher O'Malley

Hardly anyone talks much about the "plug" half of "plug and play" when the subject turns to making PCs easier to use. But the jumble of unique ports and cables used to connect various peripherals stirs the ire of even hard-boiled computer managers. And the relatively slow speed of most of these connections is threatening to choke off the data-heavy multimedia revolution.

But the IEEE's Project 1394 (P1394, also known as FireWire) is poised to simplify and greatly accelerate PC connections. P1394 is a proposed high-speed serial-bus interface standard that promises to consolidate all of today's peripheral I/O interconnections into a single, universal interface for both Mac and Windows PCs. The P1394 interface could replace parallel, serial, video, audio, SCSI, keyboard, and even AC power connections on a PC with two or three identical, narrow (less than an inch wide) serial ports that use the same thin twisted-pair cable. Multiple devices can run off each port through branching or daisy-chaining techniques.

P1394 can shuttle data at rates of 100, 200, and 400 Mbps, with four of its six shielded wires dedicated to data and control signals (the other two are used to carry power). Higher rates are possible, and they will be backward-compatible with previous speeds. Just as important as speed for many multimedia applications, P1394 supports a "guaranteed bandwidth" for real-time data transfers. However, P1394 is not intended to be a networking standard. Among other things, the distance limitations of serial interfaces would make network use problematic.

Apple, IBM, Texas Instruments, NCR, and DEC are among those represented on the P1394 committee, and all say they are committed to the new serial interface. Peripheral companies, includi ng hard drive makers Adaptec, Maxtor, and Western Digital, also say they're behind P1394. Microsoft has yet to take a position on it at this writing.

When users will begin seeing P1394 products is less clear. Apple says it will wait until next year at the earliest to use it in Macs. IBM, DEC, and others won't say when they'll begin using it. But add-on boards with the P1394 interface could begin showing up later this year. TI says it has begun production of a P1394 chip set for such boards, which will likely be available first as prototypes for PC makers.

The P1394 interface won't be just for computers. Consumer electronics and industrial companies are interested in using P1394, reports Mike Salas, a project manager at TI for P1394. That trend, he notes, will make it easier to link PCs with everything from camcorders to factory assembly lines.