by Beverly Rosenbaum
True Plug and Play is Here
USB is a peripheral bus specification developed in 1995 by a group composed of seven PC and telecom industry leaders – Compaq, Digital, IBM, Intel, Microsoft, NEC and Northern Telecom.
With additional support from a consortium of 450 technology companies, USB ports have been standard on many new PCs since early 1997. The revolutionary Universal Serial Bus is expected to be on 100 percent of desktop computers and 80 percent of notebook computers purchased by the end of this year, according to research released by Dataquest.
Universal Serial Bus is a one-size-fits-all plug and socket connection for adding a wide variety of peripherals to desktop PCs and notebooks. USB eliminates the need to install cards into dedicated computer slots and reconfigure a system. Since USB will reduce the requirement for PC slots, it will allow footprint reduction for desktop systems, while replacing the standard serial, parallel and PS2 ports. The technology is expected to free up space on laptops as well.
Personal computers equipped with USB allow computer peripherals to be automatically configured as soon as they are physically attached, even while the computer is running, without the need to reboot or run setup.
Since USB accommodates almost unlimited expansion on the PC, users are no longer limited by the number of available slots on their PCs. Setting IRQs, DMAs, jumper cables and resolving conflicts will no longer be necessary. The specification can support up to 127 devices simultaneously on a single computer, using what are called “hub” peripherals as additional plug-in locations. Ideal hub peripherals, such as monitors and keyboards, are located on the desktop, placing USB ports within easy reach of the user.
USB is currently supported in Windows 95 (OSR 2.1), Windows 98, and the Apple platform. In addition, USB will also be supported in the next release of Windows CE and Windows NT 5.0, as well as on the Sun and Digital platforms.
Peripheral devices available in retail stores include digital cameras, monitors, keyboards and scanners, as well as new fingerprint recognition devices, PC-based remote controls and keyboards, and force-feedback mice. There are also digital audio streaming speaker systems, uninterruptible power supplies, modems, and multiport parallel and serial adapters. USB telephones, signature pads, and digital microphones for voice recognition and wireless telephony are only a few more of the products expected to be available soon. New USB monitors support maximum resolutions of 1600x1200 at a refresh rate of 68Hz and contain self-powered USB hubs.
At 12 megabits per second, USB is up to 100 times faster than a standard serial port, and nearly 10 times faster than a standard parallel port. This means ample bandwidth for new digital peripherals, such as audio systems, digital cameras – even virtual reality goggles and data gloves can be supported.
Since USB can recognize the power needed for a device up to 500 milliAmps and supply it automatically, this technology can eliminate the power adapter brick for some peripherals.
Telecommunications devices require two-way (asynchronous) data transfers, which are not supported by serial, parallel or SCSI bus technologies. Since USB does support asynchronous, as well as isochronous data transfers, telephones can now be integrated with a PC to share voice mail and other features.
USB will also be a peripheral interface on new in-car computers this year, allowing peripherals to be used interchangeably between the in-car, home and office PCs. USB-enabled PC systems are now available commercially from IBM, Compaq, Toshiba, Siemens, and Sony. Apple has a new product called the iMac, which uses USB. USB is also a key feature on many notebook computers from manufacturers including Hitachi, NEC, Panasonic, Sony and Toshiba. No separate software should be needed. You can tell if you have the USB-compliant version of Windows installed by using a free USB evaluation utility you can download directly from www.kavi.com/ usb/usbready.exe. Or you can right-click on the “My Computer” icon on the Windows 95 desktop and choose “Properties.” USB requires Windows version 4.00950B or later.
FireWire/IEEE 1394
FireWire is a digital-interconnect technology developed by Apple and Texas Instruments. Approved by the Institute of Electrical and Electronics Engineers for high-speed, high bandwidth serial connections, FireWire is designed for the exchange of information between PCs and consumer electronics devices that transfer large amounts of information for data-hungry multimedia hardware. It means the end of slow-streaming data services as we know them, and the wave of the future that will allow consumer electronics devices to be attached to computers. Currently, there are an extremely limited number of FireWire devices, but proponents of PC and TV convergence think the standard will be more widely adopted as time goes on. It allows data transfer at anywhere from 100 mbps to 400 mbps, and it is so plug-and-play that any device can be added to or removed from the cable while the computer is still on.
These 2 connectivity standards differ most in terms of application focus, availability and speed. The USB is available now and will address more traditional PC connections, like keyboards, mice, joysticks and handheld scanners. USB’s 12 Mb/s data rate is more than adequate for many consumer applications including more-advanced computer game devices, high-fidelity audio and highly compressed video, like MPEG-1 and MPEG-2. Most importantly, the USB feature will add nothing to system cost.
FireWire will target high-bandwidth consumer electronics connections to the PC, like scanners, digital camcorders, cameras and digital videodisc players. Since the two technologies target different peripheral connections, they will therefore be complementary. FireWire is expected to become more prevalent in about two years. It seems likely that in the future, more PCs will have both USB and FireWire connection ports. FireWire must be injected into the PC environment so that it will achieve a significant-enough presence to make it commercially feasible. Unless that happens, it will be relegated to a costly niche environment of high-end video equipment that the average computer owner will never experience.
Win 98 supports IEEE 1394, and with this connection you can daisy chain up to 63 devices to your computer through a single cord. Someday, all computers may come with only two ports. One would be USB for low-end devices such as keyboards, joysticks, gamepads, and the like, while the other would be FireWire for the faster connectivity needed by disk drives, high-end scanners, or video equipment.
FireWire was partially designed as an answer to SCSI limitations. It is based on an efficient memory model architecture that allows devices to exchange data or commands between their internal memory spaces using small connectors and cables. A high-speed bus (100Mbps - 400Mbps), FireWire supports both arbitrated asynchronous communications and high-priority isochronous transmissions necessary for real-time full motion video transfer. But, despite assurances that the bus is inexpensive to implement (particularly when compared to SCSI technology), it will likely add cost (the now defunct Byte Magazine estimated $1-$10) to peripherals.
HDTV and IEEE
The first public demonstration of high-definition television (HDTV) signals passing through an OpenCable-compliant advanced digital set-top used the IEEE 1394 interconnect standard. The demonstration was conducted at the National Cable Television Association’s Cable ‘98 Show in Atlanta in May of this year. Dr. Tommy Poon, a senior vice president of Mitsubishi Electric said, “This demonstration is another milestone for the future success of HDTV. We’re pleased to join cable industry efforts to give consumers the ability to receive full HDTV signals via the cable system and digital set-tops directly to their HDTVs. The 1394 standard provides the basis for many new services to the home.”
At this time, however, interface card maker Adaptec seems to be the only real force behind mating FireWire peripherals and computers. Adaptec’s implementation of the IEEE 1394 serial bus enables PC and Macintosh computers to connect to current and emerging 1394 peripherals, including Digital Video camcorders, digital VCRs, color printers, scanners, digital still cameras, DVD players, and more.
Digital video (DV) is the first application to embrace 1394 technology. DV camcorders with 1394 interfaces first went on sale in 1995. But it wasn’t until 1997, when Adaptec began shipping the world’s first video-capable 1394 host adapter, that video enthusiasts could connect these DV camcorders directly to their computers and create an all-digital video editing station.
Taking advantage of Windows 98’s built-in driver support, Compaq has integrated two of the USB and one of the FireWire ports right on the front of their Presario’s mini-tower case, concealed behind a flip-up door (there’s also a FireWire port on the back of the PC). These are part of the system’s Digital Creativity Imaging Center, which also provides the software tools to create, enhance, and edit both still and moving video images.
Beverly Rosenbaum is a HAL-PC member who can be contacted at brosen@hal-pc.org.
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