What is the difference between USB and USB 2.0?
This question was answered on June 10, 2002. Much of the information contained herein may have changed since posting.
The USB or Universal Serial Bus standard was originally developed as a way to deal with the 'port cram' problem that plagued the personal computer industry from the beginning.
Most personal computers in the early days had 2 serial ports and 1 parallel port, meaning that a total of three devices could interface with the computer The typical configuration was a mouse (serial), a modem (serial) and a printer (parallel)
This left no room for expansion, so as other devices such as scanners, digital cameras and handheld computers became popular, this lack of ports created real problems Most users either manually unplugged one device to connect another or had to install special hardware that would allow one or two additional components.
The USB 1.1 standard (there was never a 1.0) was created as a method of 'daisy chaining' devices through a single port with support for up to 127 devices on a single computer.
Because it shared the connection it needed to support a higher data rate than the traditional serial port rate of 256kpbs USB 1.1 was capable of up to 12 Mbps (Mega Bits Per Second), which was 48 times faster than the old serial transfer rate.
The USB standard also supports 'hot-swapping', which means it does not require that the computer be turned off and back on again in order to activate the device.
But, as USB become popular, more and more devices that required a faster 'data bus' were developed This made transferring data through USB rather slow, especially if several devices that required constant data streams, such as speakers or external storage devices were connected.
Meanwhile, another standard known as IEEE 1394 or 'FireWire' was being developed by Apple that introduced data rates as high as 400 Mbps, making it the obvious choice for devices like digital video cameras, external hard drives and external tape drives.
To compete with the IEEE 1394 standard, the USB consortium went to work on a faster version, hence the USB 2.0 standard.
The USB 2.0 standard supports data rates of up to 480 Mbps, which is more suited to today's large formats in music, video and data in devices such as digital cameras, MP3 players and external CD burners and hard drives.
Very few computers or devices are currently incorporating USB 2.0, but you should see many desktops, laptops, printers, scanners and digital cameras supporting it by the 3rd and 4th quarters of 2002.
USB 2.0 is fully compatible with USB 1.1 meaning you can use the same cables and connectors, however, until your computer is equipped with the USB 2.0 standard, you won't get the performance benefits.
Both the computer and the device have to fully support USB 2.0 in order to gain the increase in performance Devices such as keyboards and mice won't really benefit from the increased performance of the 2.0 standard, so don't waste your money.
Feel free to start buying peripherals that support 2.0 since they will work with your current 1.1 ports and when you eventually purchase a desktop or laptop with USB 2.0 support you will get the increase in performance.
If you really want to get started now, you can purchase add-on cards and adapters for your desktop or laptop from companies such as Adaptec (www.adaptec.com) and Belkin (www.belkin.com) for less than $100.
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Posted by Ken Colburn of Data Doctors on June 10, 2002