DOS 3.3: One of three operating systems used by the Apple IIGS; 3.3 is the version number.

DOS 33 System Master: A disk that used to be packed with 5.25-inch disk drives. It performed some of the functions now handled by the Apple IIGS System Disk. It has programs for initializing disks, for copying DOS 3.3-based applications and documents, and more.

dot matrix printer: A type of printer that forms characters with patterns of dots.

double-click: To position the pointer where you want an action to take place, and then press and release the mouse button twice in quick succession without moving the mouse.

double-high resolution: A graphics mode that can display information using a rectangular array of 560 horizontal by 192 vertical dots for black and white and 140 horizontal by 132 vertical dots for 16 colors.

Down Arrow: A key that you can press (in some applications) to make the cursor move down one line.

download: To send a file from one computer to another.

drag: To position the pointer on something, press and hold the mouse button, move the mouse, and release the mouse button. When you release the mouse button, you either highlight a selection or move an object to a new location.

drill-and-practice application: A type of educational application that presents information, tests your retention of the material, and gives feedback based on your answers.

drive: See disk drive.

drive number: An application might ask you to distinguish between disk drives by number. Drive 1 is the drive of its type connected closest to the computer or to the connector labeled Drive 1 on a disk drive controller card. Drive 2 is the drive of its type connected to drive 1 or to the connector labeled Drive 2 on a disk drive controller card.

drive 1: The disk drive where you put the application program disk you want to start up.

drive 2: See drive number.

DSR: Stands for Data Set Ready. A handshake signal used to regulate the flow of data between the computer and a peripheral device.

DTR: Stands for Data Terminal Ready. A handshake signal used to regulate the flow of data between the computer and a peripheral device.

duplex: See full-duplex modem and half-duplex modem.

Dvorak keyboard: A keyboard layout designed to increase typing speed and efficiency by locating the keys used most often in the home row. Also called the American Simplified Keyboard.

echo: A copy on your own screen of a message you send via a modem. The echo can come from the remote computer (the computer on the other end of the phone line) or from you own computer.

Edit menu: A menu in most mouse-based programs that lists editing commands—like Copy, Cut, and Paste.

educational software: Software that teaches something. Also called courseware. See also computer-aided instruction.

8-bit processor: A processor that can address 65,636 memory locations directly.

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Glossary