The Next Step, Hi-Speed USB 2.0

Introduction

Advantages of USB are that the USB controller takes one IRQ; none of the other devices require one. On USB devices, there are no jumpers to configure or hardware settings with which to fiddle. Configuration is very painless and simple. The utopia of plug-and-play operating systems will automatically (in most cases) install the device and drivers for you. USB uses conntector standards for all devices that leads to less confusion for the consumer. Think about all of the connections that are on the back of your typical PC. There is probably a PS2 mouse port, PS2 keyboard port, a nine-pin serial port (or two), a 25-pin printer port, and sound card ports (speaker out, line in, microphone in). That's a lot of ports to contend with, but what if all the devices used the same connector? If all of those devices where USB devices, you would be that much closer to the Legacy-Free dream system that Intel has been telling us about for the last couple of years.

USB supports multiple devices on the same port. The USB port will technically support up to 127 devices attached to it at one time. Of course, you will have to use some sort of USB hub to connect all of these devices. The USB bandwidth is shared between all devices on the channel. So, if some of your devices reserve a specific amount of bandwidth from the USB port, the amount of devices you can connect will be reduced. To get more bandwidth from USB, you would have to add additional USB ports, usually in the form of a PCI card. USB devices consist of, among other things, keyboards, mice, game controllers, cameras, storage devices, and scanners. If there is a device that you want for your PC, it is likely that is available as a USB device. With all of the devices currently available, especially the ones that require some bandwidth, the standard USB 1.1 specification just doesn't have the kind of "oomph" that it used to have.