History of USB Development
If we looked at USB as a family, then the grandfather would be USB 1.0, which in 1998 was updated to USB 1.1. This technology slowly took the place of PS/2 ports on PC computers, and also made it more viable to push larger amounts of information to printers. The human interaction devices like the keyboard and mouse soon started to ship with USB connectors. In 1998, Apple introduced exclusive use of USB ports on their iMac. According to WikiPedia, this pushed the technology into the marketplace like never before.
USB devices have some unique features. Did you know one USB controller can have 127 devices attached to it? You could accomplish this by daisy chaining several USB hubs to one another, until you had 127 devices attached to a single port on the host computer. (Editor’s note: Whether or not the motherboard would provide enough power to the USB ports to actually have the devices operational is another story!)
USB technology relies on pipes to relay information between the peripheral device and the host computer. These pipes are one way avenues for information, with 16 going to the host and 16 coming from the controller. Without getting too technical, the pipes are constantly asking the host controller if any information needs to be pushed through. Each USB device has to be installed by a driver when the computer is on. If the computer powers off, each of the devices using USB technology will reinstall the driver so they can become operable.
In the early version of USB technology, there were two competing host controller device standards. One pushed by Intel called the Universal Host Controller Interface or UHCI was done away with in USB 2.0 by the Enhanced Host Controller Interface (EHCI). The USB-IF regulates the technology behind USB and they demanded there not be competing host controller technology in USB 2.0, as it caused problems for hardware manufacturers when working with USB 1.x. As of September 2008, we have used USB 2.0 as our fully compatible standard, but that will soon change with USB 3.0. While USB 3.0 should come to the market within a year, all the old USB devices will still be backwards compatible, meaning you will still be able to attach a USB 2.0 device to a USB 3.0 port on a new computer.
How to Add USB 2.0 Ports to an Old PC
What if you need to add USB 2.0 ports to an old computer? You can do this through additional cards placed in the motherboard. Many online and outlet electronic retailers offer USB expansion cards for next to nothing.
You can find a USB 2.0 expansion slot card with four external and two internal ports for around $15. The card installs into a PCI slot on your motherboard. I have compiled a step by step guide to show how to install this new USB card into your computer.
Installing new USB ports would really only be necessary if you only had old USB 1.x ports in the computer. Some computers may only have two ports on the back, if they were really inexpensive models. You could install an expansion card, or you could just buy a USB hub, which would allow you to externally expand the number of USB ports you have available, making room for a printer, digital camera, or other such device. For those who want to install an expansion card, here are the instructions.