ISYS 263 CH 3

any machinery (most of which uses digital circuits) that assist in the input, processing, storage, and output activities of an information system
central processing unit (CPU)
the part of the computer that consists or three associated elements: the arithmetic/logic unit, the control unit and the register areas
arithmetic/logic unit (ALU)
the part of the CPU that performs mathematic calculations and makes logical comparisons
control unit
the part of the CPU that sequentially accesses program instructions decodes them and coordinates the flow of data in and out of the ALU registers primary storage and even secondary storage and various output devices
a high-speed storage area in the CPU used to temporarily hold small units of program instructions and data immediately before, during, and after execution by the CPU
primary storage (main memory; memory)
the part of the computer that holds program instructions and data
instruction time (l-time)
the time it takes to perform the fetch-instructions and decode instruction steps of the instruction phase
execution time (E-times)
the time it takes to execute an instruction and store the results
machine cycle
the instruction phase followed by the execution phase
a form of CPU operation in which multiple execution phases are performed in a single machine cycle
system unit
components responsible for processing are housed together in the same box
millions of instructions per second, a measure of machine cycle time
clock speed
a series of electronic pulses produced at a predetermined rate that affects machine cycle time
predefined, elementary circuits and logical operations that the processor performs when it executes an instruction
millions of cycles per second
billions of cycles per second
Moore's Law
a hypothesis stating that transistor densities on a single chip double every two years
eight bits that together represent a single character of data
random access memory (RAM)
a form of memory in which instructions or data can be temporarily stored
used for storage modules for USB drives and digital camera memeory cards
NOR Flash
flash memory that supports 1-byte random access so that machine instructions can be fetched and executed directly from the flash chip just like computers fetch instructions from main memory
read-only memory (ROM)
a nonvolitile form of memory that provides permanent storage for data and instructions that do not change
cache memory
a type of high-speed memory that a processor can access more rapidly that main memory
the simultaneous execution of two or more instructions at the same time
the part of the computer that speeds processing by executing specific types of instructions while the CPU works on another processing activity
multicore microprocessor
a microprocessor that combines two or more independent processors into a single computer so they can share the workload and improve processing capacity
parallel computing
the simultaneous execution of the same task on multiple processors to obtain results faster
massively parallel processing
a form of multiprocessing that speeds processing by linking hundreds or thousands of processors to operate at the same time, or in parallel, with each processor having its own bus, memory, disks, copy of the operating system and applications
grid computing
the use of a collection of computers often owned by multiple individuals or organizations, to work in a coordinated manner to solve a common problem
cloud computing
using a giant cluster of computers to serve as a host to run applications that require high-performance computing
secondary storage (permanent storage)
devices that store larger amounts of data instruction and information more permanently than allowed with main memory
sequential access
a retrieval method in which data must be accessed in the order in which it is stored
direct access
a retrieval method in which data can be retrieved without the need to read and discard other data
sequential access storage device (SASD)
a device used to sequentially access secondary storage data
direct access storage device (DASD)
a device used for direct access of secondary storage data
magnetic tape
a secondary storage medium; Mylar film coated with iron oxide with portions of the tape magnetized to represent bits
magnetic disk
a common secondary storage medium, with bits represented magnetized areas
redundant array or independent/inexpensive disk (RAID)
a method of storing data that generates extra bits of data from existing data, allowing the system to create a "reconstruction map" so that if a hard drive fails, the system can rebuild lost data
disk mirroring
a process of storage data that provides an exact copy the protects users fully in the event of data loss
virtual tape
a storage device that manages less frequently needed data so that it appears to be stored entirely on tape cartridges, although some parts of it might actually be located on hard disks
optical disc
a rigid disc of plastic onto which data is recorded by special lasers that physically burn pits in the disc
compact disc-read-only memory (CD-ROM)
a common form of optical disc on which data once it has been recorded cannot be modified
digital video disc (DVD)
a storage medium used to store digital video or computer data
network-attached storage (NAS)
storage devices that attach to a network instead of to a single computer
storage area network (SAN)
the technology that provides high speed connections between data storage devices and computers over a network
policy-based storage management
automation of storage using previously defined policies
data entry
converting human-readable data into a machine-readable form
data input
transferring machine-readable data into the system
source data automation
capturing and editing data where it is initially created and in a form that can be directly input to a computer, thus ensuring accuracy and timeliness
speach-recognition technology
input devices that recognize human speach
optical data reader
scanning device
magnetic stripe card
a type of card that stores limited amounts of data by modifying the magnetism of tiny iron-based particles contained in a band on the card
point-of-sales (POS) device
a terminal used in retail operations to enter sales information into the computer system
radio frequency identification (RFID)
a technology that employs a microchip with an antenna that broadcasts its unique identifier and location to recievers
a dot of color on a photo image or a point of light on a display screen
plasma display
a plasma display uses thousands of smart cells (pixels) consisting of electrodes and neon and xeon gases which are electrically turned into plasma (electrically charged atoms and negatively charged particles) to emit light
LCD display
flat display that uses liquid crystals-organic, oil-like material placed between two polarizers-to form characters and graphic images on a blacklit screen
digital audio player
a device that can store, organize and play digital music files
a standard format for compressing a sound sequence into a small file
handheld computer
a single-user computer that provides ease of portability because of its small size
a phone that combines the functionality of a mobile phone, personal digital assistant, camera, web browser, e-mail tool and other devices into a single handheld device
thin client
a low-cost centrally managed computer with essential but limited capabilities and no extra drives, such as a CD or DVD drive, or expansion slot
a more powerful personal computer that is used for technical computing, such as engineering, but still fits on a desktop
a computer designed for a specific task such as network or internet applications
the ability to increase capability of a computer system to process more transactions in a given period by adding more, or more powerful processors
blade server
a server that houses many individual computer motherboards that include one or more processors, computer memory, computer storage and computer network connections
mainframe computer
a large powerful computer often shared by hundreds of concurrent users connected to the machine via terminals
the most powerful computer systems with fastest processing speeds