CompTIA A+® Certification All-In-One For Dummies®, 2nd Edition

2.1. Minding Your Keys and Qs

The keyboard is the main device you use to interact with a computer system. Keystrokes are converted into the characters that you see onscreen, and maybe eventually print. Most keyboards have five major key parts, or groups, that contain keys grouped by specific purpose. These areas (standard desktop keyboard) are shown in Figure 2-1.

Figure 2.1. The five major keyboard key groupings.

The five major groupings on a keyboard are

• Alphanumeric: The alphanumeric keys are the keys on the keyboard that contain the letters of the alphabet, numerals, and punctuation.

• Function: The 12 function keys on a keyboard offer special features. For example, in Windows, pressing F2 renames a file or icon.

• Cursor: Use the cursor keys to move the cursor or insertion point.

• Numeric: The numeric keypad has the mathematical operators and numbers for quick, single-handed access for inputting numeric information.

• LEDs: The LEDs indicate whether features such as Caps Lock, Num Lock, and Scroll Lock are turned on or off.

Each key on the keyboard has a keyswitch that closes an electrical circuit on a grid when a key is pressed. When the key contacts the grid, the keyboard controller detects the keystroke and generates a keycode. The keycode is then converted into an ASCII code that is used to display the character onscreen.

Each location on the grid corresponds to a specific keycode. ...