Input devices allow you to get data into the computer. There was a time when the only way to get data into a computer was by typing. Early computers only accepted numbers and text as input. As the types of data users wanted to input changed, so did input devices. Modern computer users have a number of ways to input different types of data.
Keyboards are the most familiar and commonly used computer input devices, as well as the earliest available for desktop computers. Based a typewriter keyboard, they are used for the manual entry of alpha-numeric data.
Douglas Engelbart, a researcher at SRI, invented the mouse in the early 1960s. With the introduction of graphic user interfaces on PCs in the 1980s, the mouse caught on as an input device. Mice allow you to control an on-screen pointer, called a cursor, which commonly looks like an arrow. When the cursor is positioned over screen elements, you press buttons on the mouse to perform tasks. Early mice had only one button, but modern mice have three or more.
Tablets allow you to write or draw directly into the computer. Using a pen-like object called a stylus, you write on the tablet surface as if it were a sheet of paper. Some tablets include buttons, allowing you to use them like mice. Newer tablets, and some computer monitors, allow the use of fingers instead of a stylus.
Joysticks are most commonly used when playing games. Originally, they consisted of a single movable stick and a button or two, allowing you to control a game character's movements. Modern joysticks group a number of sticks and buttons together, allowing you to control complex movements with a couple of finger flicks.
Headsets are a combination of an earphone and a microphone. Combined with voice-recognition software, headsets allow you to dictate data and commands directly into other software programs on your computer. Using a headset means you can keep your hands free for other tasks while using your computer.
Scanners work much like photocopiers. You position the document you wish to copy on the scanner's surface, then activate it. A digital image of the document is created that can be saved in the computer's memory. Scanned images must be viewed and edited in a graphics program. If you wish to convert an image, such as a document, to text for manipulation in a word processor, you need optical character recognition.
Digital cameras are also computer input devices. They range from high-end digital SLR cameras to digital video cameras to inexpensive webcams. Cameras are a fast way to get a lot of graphic information into a computer at one time.
Video Capture Hardware
Video capture hardware hooks up to your TV and allows you to copy TV programs directly into your computer, such as a digital video recorder. Once stored, you can edit the video files just like your own home videos. Video capture requires a great deal of storage space and a fast computer.
Specialized Input Devices
There are also input devices available for very specialized purposes. You can get digital scientific equipment to hook up to a computer, such as microscopes and telescope tracking controllers, for example. One company is even marketing a headset that claims to convert brainwaves into digital signals.