Reduced instruction set computer. See RISC.

Reentrant routine. A module of programming code that is executed simultaneously by more than one software module.

Refresh. The reactivation of electronic components, such as dynamic random-access memory (DRAM) and phosphor-coated display screens, to maintain information that would otherwise leak or fade away.

Register. A small amount of memory, usually one or two bytes, reserved to function as a temporary storage area during program execution.

Relation. A two-dimensional table in the formal terminology of relational databases.

Relational model. A technique used in database systems in which one or more flat files or tables create relationships

among the tables on the basis of a common field in each of the tables.

Report. The presentation of information about a given topic, typically in printed form.

Report generator. A special type of program generator that can gen-crate only one type of program -a report from a database. (See also Program generator).

Requirements list, formally written statements that specify what the software must do or how it must be structured. . Requirements planning. A broad term that includes planning for outputs, inputs, and file storage and processing requirements. It also includes specifying an) constraints and the costs and benefits associated with the system.

Resolution. (I) Referring to the number of pixels displayed across and down on a display screen. A common resolution is 640 pixels across by 480 pixels down. (2) Referring to the number of spots printed across and down in one square inch on a page. A common laser printer resolution is 300 dots per inch, meaning 300 spots across and 300 spots down per square inch.

Resource object. A device or service such as a printer or a file-server object.

Ribbon cable. A group of attached parallel wires commonly used to connect a printer or disk drive to a computer.

Ring network. An approach for linking terminals or personal computers by using a closed-loop communication channel.

RISC. An acronym for reduced in-structioruset computer. RISC is a combination of hardware and software that reduces the number of instructions in a computer's instruction set and attempts to execute each instruction as quickly as possible.

Robot. A programmable general-purpose motion machine.

ROM. An acronym for read-only memory. A permanent memory that the microprocessor can read information from, but whose contents can neither be erased nor written over - thus the name, read-only memory. ROM stores the instructions that start up the computer when the power is turned on. and stores some additional programs.

Rule. A statement about the relationships of various facts or data.

S

Save. To store information in a file.

Scanner. device that examines a pattern and converts it into a digital representation suitable for computer processing. Patterns can then be manipulated into a form suitable for the application.

Scientific visualization. Image-processing techniques that are used to interpret and visualize data captured by cameras, scanners, and sensors. By turning these data into three-dimensional moving images, researchers are able to gain new insight into problems that are difficult or impossible to interpret with numbers or words.

Scrolling. Using directional keys (cursor control keys) to move the contents of a display screen up, down, left, or right.

Search time. The time required to rotate the needed record under the read/ write head of a magnetic disk.

Second generation. Refers to computers in the time period 1958-1964, which used transistors to replace vacuum tubes.

Secondary storage. The component of a computer system in which programs and data are stored while not in use.

Sector. The smallest block of physical data that can be written to or read from a disk device.

Seek time. The time required to position the read/write head over the proper track on a magnetic disk.

Segmentation. memory management technique for allocating and addressing memory.

Semiconductor. A material (usually silicon) with properties between those of a conductor and insulator. Its resistance can be changed by electricity.

Sensor. An instrument capable of directly encoding a physical event, which is used as an input device for computer systems.

Sequencer. Software that can capture, edit, and play back music.

Sequential file. A file organization method that involves storing records in a predetermined sequence based on one or more key fields.

Serial. The transmission, processing, or storage of data one bit at a time.

Server. A computer running software that fulfills requests from clients across a network. (See also Client).

Shareware. Referring to a marketing method in which a software publisher distributes copies of a software package for free, often encouraging potential ushers to give copies to their friends. potential user tries out the software, and, if satisfied, pays the software publisher.

Silicon. A nonmetallic element that is commonly used in the fabrication of integrated-circuit chips.

Silicon compiler. A program used in the development of integrated circuits that translates high-level block diagrams into detailed transistor circuits.

Simulation. A computerized representation of a process or set of activities.

Single tasking. A technique in which an operating system runs one application program or task at a time.

Smart sensor. Devices that combine a computer and a sensor on a single silicon chip.

Soft copy. The recording of an image (computer output) on a surface such as a display screen.

Software. Programs that control the functions of a computer system.

Software development. The process of analyzing the requirements of a system, then designing, writing, and testing the software.

Software engineering. The application of scientific and mathematical principles to the design and development of producing software.

Software maintenance. The job of modifying existing programs to fix bugs or make requested changes.

Software piracy. The term used to describe the illegal or unauthorized copying of software.

Sort. To arrange records in a file into a preidentified sequence, such as alphabetically or numerically from lowest to highest.

Source code. The set of statements that make up a computer program.

Source document. A tangible piece of paper or form from which data are entered as input to a computer system.

Date: 2016-01-03; view: 693