SECTION II C omputer Peripherals: Input,
Output, and Storage Technologies
The right peripherals can make all the difference in your computing experience. A topquality monitor will be easier on your eyes—and may change the way you work. A scanner can edge you closer to that ever-elusive goal: the paperless office. Backup-storage systems can offer bank-vault security against losing your work. CD and DVD drives have become essential for many applications. Thus, the right choice of peripherals can make a big difference. Read the Real World Case 2 about the use of voice recognition technology in health care settings. We can learn a lot about the future of the human–computer interface and its business applications from this case. See Figure 3.13 . Peripherals is the generic name given to all input, output, and secondary storage devices that are part of a computer system but are not part of the CPU. Peripherals depend on direct connections or telecommunications links to the central processing unit of a computer system. Thus, all peripherals are online devices; that is, they are separate from, but can be electronically connected to and controlled by, a CPU. (This is the opposite of off-line devices that are separate from and not under the control of the CPU.) The major types of peripherals and media that can be part of a computer system are discussed in this section. See Figure 3.14 .
Input technologies now provide a more natural user interface for computer users. You can enter data and commands directly and easily into a computer system through pointing devices like electronic mice and touch pads and with technologies like optical scanning, handwriting recognition, and voice recognition. These developments have made it unnecessary to record data on paper source documents (e.g., sales order forms) and then keyboard the data into a computer in an additional data-entry step. Further improvements in voice recognition and other technologies should enable an even more natural user interface in the future.
Keyboards are still the most widely used devices for entering data and text into computer systems. However, pointing devices are a better alternative for issuing commands, making choices, and responding to prompts displayed on your video screen. They work with your operating system’s graphical user interface (GUI), which presents you with icons, menus, windows, buttons, and bars for your selection. For example, pointing devices such as an electronic mouse, trackball, and touch pads allow you to choose easily from menu selections and icon displays using point-and-click or point-and-drag methods. See Figure 3.15 .
The electronic mouse is the most popular pointing device used to move the cursor on the screen, as well as issue commands and make icon and menu selections. By moving the mouse on a desktop or pad, you can move the cursor onto an icon displayed on the screen. Pressing buttons on the mouse initiates various activities represented by the icon selected.
The trackball, pointing stick, and touch pad are other pointing devices most often used in place of the mouse. A trackball is a stationary device related to the mouse. You turn a roller ball with only its top exposed outside its case to move the cursor on the screen. A pointing stick (also called a trackpoint ) is a small button-like device, sometimes likened to the eraser head of a pencil. It is usually centered one row above the space bar of a keyboard. The cursor moves in the direction of the pressure you place on the stick. The touch pad is a small rectangular touch-sensitive surface usually placed below the keyboard. The cursor moves in the direction your finger moves on the pad. Peripherals
98 ● Module II / Information Technologies
patient’s nursing station or the doctor requesting the IV to obtain details. The nurse then would prioritize the request with
all the existing IV orders. Once IV care was completed, nurses would...
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