Universal Serial Bus (USB), a new peripheral bus standard for integrating electronic entertainment, communication, and computing into a single interface, is designed to simplify the way we connect peripherals.

USB eliminates the need to install cards into dedicated computer slots and reconfigure the system. It allows up to 127 devices to run simultaneously on a computer, with peripherals such as monitors and keyboards acting as additional plug-in sites, or hubs.

A USB hub can be connected to a USB port on the system unit. Each hub provides outlets for 7 USB devices. By plugging in more hubs, you can attach up to 127 different devices. That means greatly improved flexibility and efficiency.

One size fits all

In a nutshell, the USB standard means system units will no longer offer a confusing array of dedicated ports. Instead, USB takes the "one size fits all" approach. Four-pin USB connectors will accept virtually any USB peripheral--from mice to keyboards to printers to modems.

The full-speed USB bandwidth (12 Mbits/second) will support a wide range of multimedia and telephony devices, as well as further ISDN interfaces that accommodate future system growth. The low-speed bandwidth (1.5 Mbits/second) supports low-end devices, such as keyboards and mice. What's more, USB ports will support both full-speed and low-speed devices simultaneously.

Since USB is supported by specific chip sets on Pentium processor -- and Pentium Pro processor-equipped host PCs and software device drivers to be included in Windows95, it will be able to sense when peripherals are attached or detached. There's no hunting for the "right" connection, and, even better, there's no rebooting or reconfiguring every time a peripheral is added or removed. In fact, USB's hot insertion and removal feature lets users install and detach peripherals while the PC stays up and running.

All of this sounds like a dream come true for mobile PC users - and it is. Expect to see USB ports and adapters appearing in mobile products during 1997.

Like USB, IEEE 1394 is a new connection standard that has been developed to support the integration of varying electronic entertainment, communication, and computing equipment into a single interface. IEEE-1394 achieves data transfer rates of between and 200 Mbps (Megabits per second). That's the equivalent of 12.5 and 25 Megabytes per second. Future versions that support 400 Mbps (50 Megabytes per second) are in the development stage, and a 1.2 Gigabits (150 Megabytes per second!) version has been proposed.

This new bus technology supports scaleable architecture - up to 64,000 devices on one IEEE 1394 interface. Like USB, there are no cable terminators, device IDs, or user set-up. IEEE 1394 devices can be attached or removed at any time, even when the system is running.

Where IEEE 1394 outperforms USB is in its support of isochronous data transmission. Isochronous data transport minimises data buffer size for constant bit-rate data. This is particularly useful for the just-in-time guaranteed delivery of data, which is necessary for real-time video.

Video Reality

For this reason, many of the exciting new products for IEEE 1394 will deal with video. Sony Corporation was the first to commercialise IEEE-1394 with its highly successful Digital Video Handycam products, the DCR-VX1000 and DCR-VX700 camcorders, introduced to the North American market in autumn 1995. Sony also produces a high-performance IEEE-1394 video camera, the CCM-DS250, for use in video conferencing and similar applications.

This year's CeBIT should see the first peripherals for both USB and IEEE 1394. USB and 1394 are not only compatible but also complementary. USB is cheap to implement and supports lower speed devices leaving IEEE 1394 to support high-speed devices. Mobile PC users will get the first real look at IEEE 1394 some time in 1998.