Exam 2
CD-ROM
(computer science) memory whose contents can be accessed and read but cannot be changed
Access Time
(computer science) the interval between the time data is requested by the system and the time the data is provided by the drive
Mesh Topology
(point-to-point connections among every node pair) provides high capacity at the expense of high complexity and cost
Solid-State Drive
A(n) __________ mimics the behavior and physical size of a magnetic disk drive but has no moving parts.
UDP
19. The __________ protocol is used with broadcast and multimedia applications when processing overhead needs are low and reliable delivery doesn't need to be guaranteed.
Line Turnaround
2. During half-duplex transmission, sender and receiver switch roles after a(n) __________ message is transmitted.
Session
2. The OSI __________ layer establishes and manages connections between clients and servers
Analog
20. A(n) __________ signal can encode an infinite number of possible numeric values.
H.323
20. The oldest and most widely used VoIP protocol suite is __________.
Inkjet
A(n) __________ printer forces ink onto a page by heating it or forcing it out with a piezoelectric membrane.
MAC
A(n) __________ protocol defines the rules governing a network node's access to a transmission medium.
Binary
A(n) __________ signal is a discrete signal that can encode only two possible values.
Carrier
A(n) __________ wave transports encoded data through a transmission medium.
PostScript
An Adobe image description language designed mainly for printed documents, although it's also a programming language for generating video display output.
Portable Document Format (PDF)
An Adobe image description language developed to generate and manage documents as an integrated whole rather than a collection of independent images and pages.
802.11g
An IEEE wireless networkign standard that combines teh ferquencies and bitencoding methods of 802.11b with the OFDM transmission method of 802.11a; raw transmission speeds are the same as 802.11a.
802.11a
An IEEE wireless networkin standard that divides frequency bands in the 5.2, 5.7, and 5.8 Ghz ranges into 12 channels; uses orthogonal frequency division multiplexing (OFDM) to achieve standard transmission speeds of 6,9,12,18,24,36,48, and 54 Mbps.
802.11b
An IEEE wireless networking standard that divides the 2.4 GHz band into 14 channels, each with 22 MHz of bandwidth; uses direct sequence spread spectrum (DSSS) to yield raw data transfer rates of 22, 44, and 88 Mbps
802.11n
An IEEE wireless networking standard that expands on 802.11g; capable of broadcasting or receiving on up to four frequencies in the 2.4 or 5 GHz bands.
passive matrix display
An LCD that shares transistors among rows and columns of pixels.
active matrix display
An LCD that uses one or more transistors for every pixel.
interrupt handler
An OS service routine that processes interrupts; each interrupt handler is a separate program stored in a separate part of primary storage.
level one (L1) cache
An SRAM cache between the CPU and SDRAM primary storage, used to limit wait states; the L1 cache is closest to the CPU.
level two (L2) cache
An SRAM cache between the CPU and SDRAM primary storage, used to limit wait states; the L2 cache is the next level away from the CPU.
level three (L3) cache
An SRAM cache between the CPU and SDRAM primary storage, used to limit wait states; the L3 cache is the farthest level away from the CPU.
pixel
An abbreviation of "picture element," it's a single unit of data in an image; also refers to a single point on a display surface.
direct access
An access method that can access any storage location directly and in any order; primary storage devices and disk storage devices use random access.
random access
An access method that can access any storage location directly and in any order; primary storage devices and disk storage devices use random access...
parallel access
An access method that can access multiple storage locations simultaneously; can also be achieved by subdividing data items and storing the component pieces on multiple storage devices...
serial access
An access method that stores and retrieves data items in a linear (sequential) order; mainly used to hold backup copies of data stored on other storage devices...
cache hit
An access to data already contained in the cache.
cache miss
An access to data that isn't stored in the cache.
decompression algorithm
An algorithm that restores compressed data to its original or nearly original state.
electromagnetic interference (EMI)
An alteration of wave characteristics caused by external electrical or magnetic phenomena, such as radio equipment and nearby power lines.
scaling out
An approach to increasing processing and other computer system power by partitioning processing and other tasks among multiple computer systems; examples include clusters and grids.
scaling up
An approach to increasing processing and other computer system power by using larger and more powerful computers; examples include multicore and multiple-processor architectures.
switched fabric
An architecture for interconnecting devices with multiple data transmission pathways and a mesh of switches resembling the interwoven threads of fabric.
cache
An area of high-speed memory (usually RAM) for storage device accesses that improves the performance of read and write operations.
Drive array
An arrangement of hard drives enclosed in a storage cabinet and accessed as though they're a single storage device
digital-to-analog converter (DAC)
An audio device that accepts a bitstream representing sound samples and generates a continuous analog signal that can be amplified and routed to a speaker.
analog-to-digital converter (ADC)
An audio device that accepts a continuous electrical signal representing sound, samples it at regular intervals, and outputs a bitstream representing the samples. See also sampling.
video display terminal (VDT)
An early I/O device containing an integrated keyboard and TV screen; capable of displaying only text and primitive graphics.
802.11
An early IEEE wireless networking standard that defines a 2 Mbps maximum raw data transfer rate in the 2.4GHz band.
dual inline packages(DIPS)
An early form of packaging for RAM or ROM circuits; had two rows of electrical contact pins.
NIC
An end node's hardware interface to a network transmission medium is called a(n) __________.
stack overflow
An error condition that occurs when attempting to push register values onto a stack that's already at its maximum capacity.
buffer overflow
An error condition that results when receiving more data than can be stored in a buffer.
Block checking
An error-checking method for groups of characters or bytes in which the sender combines parity bits for each position into a block check character and adds it to the end of the block.
longitudinal redundancy checking (LRC)
An error-checking method for groups of characters or bytes in which the sender combines parity bits for each position into a block check character and adds it to the end of the block.
odd parity
An error-detection method in which the sender sets the parity bit to 0 if the count of 1-valued data bits in the character is odd and to 1 if the count of 1-valued data bits is even.
even parity
An error-detection method in which the sender sets the parity bit to 0 if the count of 1-valued data bits is even or to 1 if the count of 1-valued data bits is odd.
sound card
An expansion card connected to the system bus that contains components for sound input and output.
dot matrix printer
An impact printer that moves a print head containing a matrix of pins over the paper, and a pattern of pins matching the character or symbol to be printed is forced out of the print head.
host channel adapter (HCA)
An interface that connects a device to an InfiniBand switch; used by devices, such as general-purpose servers, that can initiate and respond to data transfer requests.
target channel adapter (TCA)
An interface that connects a device to an InfiniBand switch; used by simpler devices, such as network switches and storage applications.
cathode ray tube (CRT)
An older video display device that's an enclosed glass vacuum tube with an electron gun generating a narrow beam of electrons toward the tube's front surface, which is coated with colored phosphors that emit light when struck by electrons.
Amplitude
21. __________ is a measure of peak signal strength.
Star Bit
22. In asynchronous transmission, at least one __________ is added to the beginning of each message.
Modulation
23. The term __________ describes encoding data as variations in one or more physical parameters of a signal.
Asychronous
24. In __________ transmission, blocks or characters arrive at unpredictable times, and no signal is transmitted during idle periods.
Bandwidth
25. A medium's __________ is the difference between the highest and lowest frequencies that can be transmitted.
Full Duplex, Half Duplex
26. __________ mode implements two-way transmission with two separate communication channels; __________ mode implements two-way transmission with only one communication channel.
Amplitude modulation or AM
27. __________ encodes data by varying the magnitude of wave peaks in an analog signal.
Parallel
28. __________ transmission uses multiple lines to send multiple bits simultaneously.
Repeater
29. A(n) __________ extends a signal's range by retransmitting the signal without any noise or distortion from earlier transmission stages.
IPv6
3. The __________ protocol is an updated version with larger addresses and improved support for multicasting and multimedia data
Frequency modulation or FM
3. __________ encodes data by varying the distance between wave peaks in an analog signal.
Block (or vertical redundancy) checking, block check character or BCC
30. __________ generates a(n) __________ consisting of a single parity bit for each bit position in the group of characters or bytes.
Synchronous
31. In __________ transmission, signals are transmitted continuously, even when there's no data to send, to ensure clock synchronization.
Multilevel coding
32. __________ uses more than two signal characteristic levels to encode multiple bits in a single signal.
On-off keying
33. __________ encodes bit values with rapid pulses of electrical or optical power.
Crosstalk
34. __________ is noise added to the signal from EMI generated by adjacent transmission lines in a parallel communication channel.
Wavelength-Division Multiplexing
35. Frequency-division multiplexing of optical channels is sometimes called __________.
Skew
36. The length of a parallel communication channel is limited by __________, which can cause bits to arrive at slightly different times.
ACK, NAK
37. A receiver informs a sender that data was received correctly by sending a(n) __________ message. It informs the sender of a transmission or reception error by sending a(n) __________ message.
Attenuation
38. __________ is loss of signal strength as it travels through a transmission medium.
Packets
39. Messages transmitted by time-division multiplexing are divided into __________ before physical transmission.
Modem
4. A(n) __________ converts a digital signal to an analog signal so that digital data can be transmitted over analog phone lines.
Star, Bus
4. The __________ topology is most common in wired networks, and the ___________ topology is most common in wireless networks.
cache swap
An operation performed after a cache miss. The cache controller guesses which data is least likely to be needed in the near future, writes it to the storage device, and purges it from the cache. The requested data is then read from the storage device and placed in the cache.
bar-code scanner
An optical input device that detects specific patterns of bars or boxes representing numeric data.
mark sensor
An optical input device that scans for light or dark marks at specific locations on a page.
Moving Picture Experts Group(MPEG)
An organization that creates standards for motion picture recording and encoding technology; each standard is divided into layers numbered 1 (systems), 2 (video), and 3 (audio).
noise
Anything that interferes with, distorts, or slows down the transmission of information
character-framing methods
Approaches to clock synchronization when messages consist of ASCII or Unicode characters.
diversity
As specified int eh 802.11n standard, using antenna pairs for redundant data transmission across different frequencies to increase signal reliability
Network Interface
At the sending node, the ____ layer's role is to translate IP datagrams into a format that can be transported and forwarded over a specific physical network.
Defragmenting
Average access time can usually be improved by __________ files stored on a disk.
digitizer
A device consisting of a digitizing tablet and a pen, stylus, or both that captures a pointing device's position as input data.
I/O Channel
A device controller dedicated to a mainframe bus port that enables many devices to share access to, and the capacity of, the port; originally used to describe a specific hardware component of IBM's 7000 series mainframe computers.
storage medium
A device or substance in a storage device that actually holds data...
photosensor
A device that converts incoming light energy into outgoing electrical energy.
repeater
A device that functions much like an amplifier but extracts data embedded in the signal it receives and retransmits a new signal containing the same data; therefore, noise or distortion aren't retransmitted.
optical scanner
A device that generates bitmap representations of printed images; detects light reflected from the page with an array of photosensors.
audio response unit
A device that generates spoken messages based on text input; commonly used for automated phone bank tellers and automated call routing.
amplifier
A device that increases a signal;s amplitude and can extend a signal's range by boosting signal power to overcome attenuation; a drawback is that any existing noise or distortion in the signal is amplified as well.
modulator-demodulator(modem)
A device that translates analog signals into digital signals and vice versa, enabling computer hardware to communication over voice-grade phone lines.
grayscale
A display device or encoding method that can display black, white, and shades of gray but no other colors.
monochrome
A display device or encoding method that can display only one of two colors (usually black and white), so it requires only 1 bit per pixel
Peripheral Component Interconnect (PCI)
A family of bus standards, developed by Intel in the early 1990s, found in nearly all small and midrange computers of that era; largely replaced by PCI Express since the late 2000s.
single-mode cable
A fiber-optic cable with fibers that are much thinner in diameter than multimode fibers and vary continuously in density form center to edge to eliminate light reflections.
DVD read-only memory (DVD-ROM)
A format for general-purpose read-only data storage on DVD.
input pad
A general class of input devices that convert pressure into input, such as for capturing signatures or drawings; these devices typically use infrared detectors, photosensors, pressure-sensitive pads, or magnetic fields.
nonvolatile memory (NVM)
A generic term for memory devices with long-term of permanent data retention...
linear recording
A geometric approach to recording data on a tape surface in which bits are placed along parallel tracks that run along the tape's entire length....
GST
A glasslike compound, used in phase-change memory, that can change between amorphous and crystalline states...
fiber-optic cable
A guided transmission medium for optical signals,generally consisting of plastic of glass fibers sheathed in a protective plastic coating.
broadband
A high-bandwidth communication channel
image description language (IDL)
A language (usually device independent) that uses compact bit strings or ordinary ASCII or Unicode text to describe primitive image components, such as straight lines and simple shapes; reduces storage space requirements because a description of a simple image component is usually much smaller than a bitmap.
narrowband
A low-bandwidth communication channel; typically a subchannel of a broadband channel.
Linear Tape Open (LTO)
A magentic tape standard developed by Hewlett-Packard, IBM, and Seagate; uses linear recording and has technology improvements in tape cartridges, coercible materials, read/write heads/ and tape control....
hard disk
A magnetic disk medium with a rigid metal base (substrate) where data is recorded as patterns of magnetic charge...
Super Digital Linear Tape (SDLT)
A magnetic tape standard developed by Quantum Corporation; the cartridge has only one reel and the device records in parallel linear tracks in an end-to-end format...
Mammoth
A magnetic tape standard, developed by Exabyte, based on Digital Audio Tape; uses helical scanning and an improved tape drive technology to pack more data onto a single tape....
compression algorithm
A mathematical compression technique implemented as a program for translating data inputs into equivalent but smaller data outputs.
signal-to-noise (S/N) ratio
A mathematical relationship between the power of a carrier signal and the power of noise in the communication channel; measured in decibels.
dots per inch (dpi)
A measure of print or display resolution (pixel density); a smaller pixel size represents a higher dpi and, therefore, higher image or print quality. See also resolution.
amplitude
A measure of wave height or power; the maximum distance between a wave's peak and its zero value.
asynchronous transmission
A method in which messages are sent on an as-needed basis, so sender and receiver don't synchronize their clocks ontinuously.
direct memory access (DMA)
A method of data transfer that enables the CPU to execute instructions while another device (the DMA controller) manages all transfers between memory and other storage or I/O devices.
synchronous transmission
A method that ensures sender and receiver clocks are always synchronized by sending data in continuous streams of fixed-size byte groups called "blocks"
multicore architecture
A microprocessor architecture that embeds multiple CPUs and cache memory on a single chip.
keyboard controller
A microprocessor integrated into a keyboard that generates a bitstream output of scan codes according to an internal program or lookup table. See also scan code.
digital signal processor (DSP)
A microprocessor specialized for processing continuous streams of audio or graphical data; commonly embedded in audio and video hardware.
amplitude modulation (AM)
A modulating method that represents bit values as specific wave amplitudes.
amplitude-shift keying (ASK)
A modulating method that represents bit values as specific wave amplitudes.
frequency modulation (FM)
A modulation method that represents bit values by varying carrier wave frequency while holding amplitude constant.
frequency-shift keying (FSK)
A modulation method that represents bit values by varying carrier wave frequency while holding amplitude constant.
phase-shift keying (PSK)
A modulation method that represents bits as sudden shifts in wave phase.
phase-shift modulation
A modulation method that represents bits as sudden shifts in wave phase.
large-format printer
A more current term for plotters. See also plotter.
multiple-processor architecture
A more traditional approach to multiprocessing that uses two or more processors on a single motherboard or set of interconnected motherboards; slower than multicore architecture.
multimode graded-index cable
A multimode fiber-optic cable in which fibers vary in density from the center to the edge, which reduces the number of light reflections
Router
A physical connection between two different networks is implemented by using a(n) __________.
plotter
A printer that generates line drawings on sheets or rolls of paper up to 64 inches wide. See also large-format printer.
laser printer
A printer that operates by charging areas of a photoconductive drum; toner is attracted to charged areas of the drum and then to paper.
inkjet printer
A printer that produces printed images by placing small drops of liquid ink onto paper; ink is forced out of the nozzle by mechanical movement or by heat.
dithering
A process that generates continuous color approximations by placing small dots of different colors in an interlocking pattern.
device controller
A processor that controls the physical actions of storage and I/O devices; connects these devices to the system bus or a subsidiary bus.
logical access
A read or write operation from the hypothetical storage device representing a peripheral device.
synchronous DRAM (SDRAM)
A read-ahead RAM that uses the same clock pulse as the system bus; read and write operations are broken into simple steps that can be completed in on bus clock cycle...
Connectionless
A receiver can't detect loss of datagrams if a(n) __________ protocol is used.
ACK
A receiver informs a sender that data was received correctly by sending a(n) __________ message.
NAK
A receiver informs the sender of a transmission or reception error by sending a(n) __________ message.
attenuation
A reduction in signal amplitude caused by interactions between the signal's energy and the transmission medium; proportional to the medium's length
interrupt register
A register in the CPU's control unit that stores interrupt codes received over the bus or generated by the CPU.
stack
A reserved area of primary storage accessed on a last-in, first-out (LIFO) basis; this mechanism enables a program suspended by an interrupt to resume execution in exactly the same state as before an interruption.
magnetic tape
A ribbon of plastic with a coercible (usually metallic oxide) coating, used to store data...
magneto-optical (MO) drive
A secondary storage device that uses a laser and reflected light to sense magnetically recorded bit values; data reading is based on the polarity of the reflected laser light, which is determined by the polarity of the magnetic charge...
vector list
A series of concatenated or linked vectors that can be used to construct complex shapes; images constructed from a vector list resemble connect-the-dots drawings
double data rate (DDR)
A series of technologies, each doubling the data transfer rate of the previous synchronous DRAM version .
bar code
A series of vertical bars of equal length but varied thickness and spacing, used to encode numeric data.
Internet Control Message Protocol
A set of messages/responses used to report and diagnose errors
communication protocol
A set of rules and conventions for representing the content of data and commands, encoding and transmitting data (bits), channel organization, and communication coordination (clock synchronization and error detection and correction)
bus
A shared electrical or optical communication channel that connects two or more devices in a computer or network.
interrupt
A signal sent to the CPU over the control bus that some event requires it to execute a specific program or process; used to prevent inefficiency caused by I/O wait states.
digital signal
A signal that can contain on of a finite number of possible values.
discrete signal
A signal that can contain on of a finite number of possible values.
analog signal
A signal that uses the full range of a carrier wave characteristic to encode continuous data values; because it's continuous in nature, it can represent any data value within a range of values.
on-off keying (OOK)
A signal-coding method that generates square waves by rapidly switching (pulsing) an electrical or optical power source to represent bit values.
bus arbitration unit
A simple processor attached to a peer-to-peer bus that decides which devices must wait when multiple devices want to become a bus master.
tape drive
A slow serial access device containing motors that wind and unwind tapes and read/write heads to access tape content...
single inline memory module (SIMM)
A small printed circuit board that incorporates multiple DIPs and has a row of electrical contacts on the edge; the entire package is designed to lock into a SIMM slot on a motherboard....
double inline memory module(DIMM)
A small printed circuit board that's essentially a SIMM with independent electrical contacts on both sides of the module.
buffer
A small reserved area of main memory (usually DRAM or SRAM) that holds data in transit from one device to another and is used to resolve differences in data transfer unit size.
cache controller
A special-purpose processor or software that manages cache content; it guesses what data will be requested in the near future and loads this data from the storage device into the cache before it's actually requested.
stack pointer
A special-purpose register that points to the next empty address in the stack and is incremented or decremented automatically each time the stack is pushed or popped.
phase
A specific time point in a sine wave's cycle; measured in degrees.
Musical Instrument Digital Interface (MIDI)
A standard for storing and transporting control information between computers and electronic musical instruments and synthesizers.
point
A standard measurement unit for font size; equals 1/72 of an inch.
Serial Advanced Technology Attachment (SATA)
A storage device and cabling standard commonly used in PCs; compatible with older parallel ATA standards but uses serial transmission.
Serial Attached SCSI (SAS)
A storage device and cabling standard commonly used in servers; compatible with older parallel SCSI standards but uses serial transmission.
solid state drive (SSD)
A storage device that mimics the behavior of a magnetic disk but uses flash RAM or other nonvolatile memory devices as the storage medium and read/write mechanism; expected to replaces magnetic disks gradually...
bitmap
A stored set of numbers describing the content of all pixels in an image.
video bus
A subsidiary bus that connects only memory and the video display device; improves performance by removing display update traffic from the system bus and providing a high-capacity one-way communication channel optimized for video data.
memory bus
A subsidiary bus that connects only the CPU and memory; because its data transfer rate is higher than that of the system bus, it improves overall computer performance.
storage bus
A subsidiary bus that connects secondary storage devices to the system bus; reduces the length and number of physical connections to the system bus and aggregates the lower data transfer capacity of secondary storage devices to better match the higher capacity of a single system bus connection.
cursor
A symbol on a video display that indicates the current position; also called a "pointer."
palette
A table of colors used to represent pixel color; the number of bits used to represent each pixel determines the table size.
multilevel coding
A technique for embedding multiple bit values in a single wave characteristic, such as frequency or amplitude; treats groups of bits as a single unit for the purpose of signal encoding
time-division multiplexing (TDM)
A technique that divides a channel's data transfer capacity into time slices and allocates them to multiple users.
compression
A technique that reduces the number of bits used to encode data.
thin film transistor (TFT)
A technology for manufacturing active matrix displays, in which wiring and transistors are added in thin layers to a glass substrate; similar to semiconductor fabrication technology.
Optical character recognition (OCR)
A technology that combines optical-scanning technology with a special-purpose processor or software to interpret bitmap content. See also optical scanner.
volatile
A term describing storage devices that CANNOT hold data for long periods; primary storage is usually volatile...
nonvolatile
A term describing storage devices that hold data without loss for long periods; secondary storage is usually nonvolatile...
core
A term describing the logic, computation, and control circuitry of a single CPU.
twisted-pair cable
A transmission medium consisting of two copper wires twisted around one another and encased in nonconductive material, usually plastic.
coaxial cable
A transmission medium that contains a single copper conductor surrounded by a thick plastic insulator, a metallic-shield and a tough plastic outer wrapping
guided transmission
A transmission medium that routes signals between two locations through a physical connection such as copper wire or optical fiber; also called wired transmission.
unguided transmission
A transmission medium that uses the atmosphere or space to carry messages encoded in radio frequency or light signals; Also called wireless transmission.
twin-axial cable
A transmission medium that's similar to coaxial cable but is thinner and contains two internal conductors.
dynamic RAM(DRAM)
A type of RAM that stores each bit by using a single transistor and capacitor...
video RAM (VRAM)
A type of RAM type used in a video controller; differs from ordinary RAM because it can be written by the bus interface circuitry or video processor while being read by display generator circuitry. See also dual-porting.
electronically erasable programmable ROM(EEPROM)
A type of nonvolatile memory that can be programmed, erased and reprogrammed by signals sent from a CPU; the only type of ROM that's currently used...
erasable programmable ROM(EPROM)
A type of nonvolatile memory that's manufactured blank, written with a special EPROM writer and erased by exposure to ultraviolet light...
magnetoresistive RAM (MRAM)
A type of nonvolatile memory under development that stores bit values by using two magnetic elements, one with a fixed polarity and the other with polarity that changes when a bit is written; has better longevity than conventional flash RAM...
phase-change memory (PCM)
A type of nonvolatile memory under development that uses a GST compound capable of switching between amorphous and crystalline states; has fast write times and high longevity...
OpenGL
A video controller image description language developed by Silicon Graphics but now maintained by Khronos Group as an open standard.
Direct3D
A video controller image description language that's part of the Microsoft DirectX suite embedded in Windows OSs.
liquid crystal display (LCD)
A video display device containing liquid crystals sandwiched between two polarizing filter panels; the crystals change from opaque to transparent when an electrical charge is applied.
plasma display
A video display device that uses an active matrix display and generates light by applying an electrical charge to neon gas.
light-emitting diodes (LEDs)
A video display technology that uses phosphorescent compounds to produce red, green, and blue light.
DPI
A video display's resolution is described by the units __________.
carrier wave
A wave with encoded bits in a communication channel
sine wave
A waveform that varies continuously between positive and negative states.
Access Point
A wireless ____ connects a wireless network to a wired network.
Repeater
A(n) _ extracts the data embedded in a signal it receives and retransmits a new signal containing the same data.
Square Wave
A(n) __________ can be approximated by combining a series of sine waves. Higher-quality approximations require higher bandwidth.
Image Description Language (IDL)
A(n) __________ compresses an images by replacing some image components, such as lines and shapes, with equivalent drawing command.
DMA
A(n) __________ controller assumes the role of bus master for all transfers between memory and other storage or I/O devices, leaving the CPU free to execute computation and data movement instructions
Plasma
A(n) __________ display illuminates a pixel using excited gas and a colored phosphor.
Point
A(n) __________ is 1/72 of an inch and is considered a standard pixel size.
Phoneme
A(n) __________ is a basic component of human speech.
I/O Port
A(n) __________ is a communication pathway from the CPU to a peripheral device
Interrupt Handler
A(n) __________ is a program stored in a separate part of primary storage to process a specific interrupt
Track
A(n) __________ is a series of sectors stored along one concentric circle on a platter.
Bus Arbitration Unit
A(n) __________ is a simple processor that intervenes when two devices want control of the bus at the same time
Photosensor
A(n) __________ is a small device in optical scanners and digital cameras that converts light into an electrical signal.
Cache
A(n) __________ is an area of fast memory where data held in a storage device is prefetched in anticipation of future requests for the data
Ethernet
12. The original __________ standard transmits at 10 Mbps over twisted-pair cabling. Current standard versions support 1 and 10 Gbps transmission over twisted-pair and fiber-optic cable.
Even parity, Odd Parity
12. With parity checking, sender and receiver must agree whether error detection is based on __________ or __________.
S/N ratio
13. A channel's __________ describes the mathematical relationship between noise power and signal power.
OSI model
13. The __________ defines conceptual software and hardware layers for networks.
CSMA/CA
14. The __________ MAC protocol is used in wireless networks to prevent most collisions.
Distortion
14. __________ is any change in a signal characteristic caused by components of the communication channel.
Type I, Type II
15. For any error-detection method, a decrease in ___________ is accompanied by an increase in ______________ error.
CSMA/CD
16. With the __________ MAC protocol, collisions can occur, but they're detected and corrected.
Electromagnetic interference or EMI
16. __________ can't affect optical signals but can affect electrical or RF signals.
Signal Wire, Return Wire
17. A communication channel using electrical signals must have at least two wires—a(n) __________ and a(n) __________—to form a complete electrical circuit.
Media Access Control or MAC
17. A(n) __________ protocol defines the rules governing a network node's access to a transmission medium.
Network Interface Card or NIC
18. An end node's hardware interface to a network transmission medium is called a(n) __________.
Raw data transfer rate, Effective data transfer rate
18. __________ measures a channel's theoretical capacity. __________ measures the actual capacity of a channel when a specific communication protocol is used.
frequency-division, time-division
19. Multiple messages can be transmitted on a single transmission line or circuit by __________ multiplexing or __________ multiplexing.
binary signals
Digital signals in which on of two values is encoded by modulating a wave characteristic
Push
During a(n) __________ operation, one or more register values are copied to the top of the stack
Pop
During a(n) __________ operation, one or more values are copied from the top of the stack to registers
Line Turnaround
During half-duplex transmission, sender and receiver switch roles after a(n) __________ message is transmitted.
Stack
During interrupt processing, register values of a suspended process are held on the __________
Refresh Cycles
Dynamic RAM requires frequent __________ to maintain its data content.
Pixel
Each cell in a video display surface's matrix represents a(n) __________.
radio frequency (RF)
Electromagnetic radiation propagated through space; describes transmissions using frequencies between 50 Hz and 1 THz
Digital Data Storage
Family of magnetic tape standards developed by Hewlett-Packard and Sony, and based on Digital Audio Tape. Uses Helical scanning
Sector
For most disk drives, the unit of data access and transfer is a(n) block or __________.
Wavelength Division Multiplexing (WDM)
Frequency-division multiplexing of optical channels is sometimes called __________.
Datagrams
IP accepts messages called ____ from Transport-layer protocols and forwards them to their destination.
I/O wait states
Idle processor cycles consumed while waiting for secondary storage or I/O devices to complete access requests.
Lossless
If data is the same as the original after compressing and decompressing, the compression algorithm is said to be __________
Lossy
If data isn't exactly the same as the original after compressing and decompressing, the compression algorithm is said to be __________.
Speaker-Dependent
If they are __________, these speech-recognition programs must be trained to recognize one person's voice.
Latency
In ____, the VoIP user perceives periods of silence before the other participant's speech is heard.
Synchronous
In __________ communication , signals are transmitted continuously, even when there's no data to send, to ensure clock synchronization
Parity Checking
In __________, an error-detection bit is added to each character or byte, and the bit value is determined by counting the number of 1 bits.
Bitmap
In a computer, an image is stored as a(n) __________, with each pixel represented by one or more numbers.
Access Arms
In a magnetic or optical disk drive, a read/write head is mounted on the end of a(n) __________.
Capacitance
In a touchscreen that uses _. a matrix of capacitors layered above or within the display panel is charged and reacts to presses from fingers and other electrically conductive objects.
Start Bit
In asynchronous transmission, at least one __________ is added to the beginning of each message.
cycle
In communication, the full range of a sine wave, from zero to positive peak, back to zero, to negative peak, and back to zero again.
refresh cycle
In dynamic RAM, the period during which circuitry supplies fresh infusions of power automatically; read and write operations can't be performed during this cycle. Also refers to the transfer of a full screen of data from the display generator to the monitor.
refresh cycle
In dynamic RAM, the period during which circuitry supplies fresh infusions of power automatically; read and write operations can't be performed during this cycle. Also refers to the transfer of a full screen of data from the display generator to the monitor....
core memory
In early computers, a technology for implementing primary storage as rings of ferrous materials embedded in a two-dimensional wire mesh.
return wire
In electrical transmission through wires, the channel component that completes an electrical circuit between sending and receiving devices.
signal wire
In electrical transmission through wires, the channel component used to carry data.
vector
In graphics, a line segment with a specific angle and length in relation to a point of origin; also refers to a one-dimensional array.
wavelength-division multiplexing (WDM)
In long-distance telecommunication, using FDM to multiplex single-mode optical fibers.
platters
In magnetic disk media, they're flat, circular disks with metallic coatings that are rotated beneath read/write head; data is normally recorded on both sides...
cylinder
In magnetic disks, consists of all tracks at an equivalent distance from the edge or spindle on all platter surfaces.
crosstalk
In parallel transmission channels, noise added to the signal in a wire from EMI generated by adjacent wires.
subtractive colors
In printing, the primary colors are generated by using the inverse of the primary video display colors, so cyan is the absence of red, magenta is the absence of green, and yellow is the absence of blue.
Datagram
In the TCP/IP model, a(n) __________ is the basic data transfer unit.
peer-to-peer bus
In this arrangement, any device can assume control of the bus or act as a bus master for transfers to any other device.
IPv4
Internet protocol version 4
WAN
LANs and groups of LANs
Packets
Messages transmitted by time-division multiplexing are divided into __________ before physical transmission.
Digital Audio Tape
Method of storing large amounts of data on tape using helical scan technology to write data at high densities across the tape at an angle.
DIMMs
Modern desktop and laptop computers generally use memory packaged on small standardized circuit boards called __________.
Circuit
Most local phone service uses __________ switching to route messages from a wired home phone to the local phone-switching center.
Packet
Most networks use __________ switching to enable senders and receivers to efficiently share a single communication channel.
RGB
Red, green, and blue; the primary colors for video display.
disk defragmentation
Reorganizing data on a disk drive so that a file's contents are stored in sequential sectors, tracks, and platters; an OS utility is used to perform this task.
speaker dependent
Requiring training to recognize the sounds of human speakers; a characteristic of speech-recognition systems. See also speech recognition.
wireless transmission
Same as Unguided transmission.A transmission medium that uses the atmosphere or space to carry messages encoded in radio frequency or light signals; Also called wireless transmission.
wired transmission
Same as guided transmission.
Diversity
Same info transmitted via different antennae and frequency bands Receiver selects the stronger received signal Useful in noisy/crowded environments
channel
See I/O channel or communication channel.
serial transmission
Sending bits sequentially over a single transmission line; the receiver reassembles the bits into larger data units, such as bytes.
parallel transmission
Sending each bit position of a message over a separate transmission line simultaneously.
compact disk
an optical storage medium made of molded polymer for electronically recording, storing, and playing back audio, video, text, and other information in digital form; also CD-ROM, CD-R, CD-RW
Media Access Control Protocol
any coordination method that ensures that no more than one node "speaks" at a time
Connection Less Protocol
doesn't establish or use connections: - Little/no ability to detect lost datagrams - Relies on default methods for routing, data encoding, security
Carrier Sense Multiple Access / Collision Detection
earlier generations of wired bus networks (e.g., 10 MBps Ethernet) use a MAC protocol
SATA
Serial transmission standards, including SAS and __________, are replacing parallel transmission standards for connecting secondary storage devices and controllers.
Type 2 error
Shows there is not an effect or difference when one exists
Category 5
Similar to Category 6, but can't achieve the same transmission speeds reliably.
half-toning
Simulating shades of gray by dithering black and white dots. See also dithering.
Firmware
Software programs stored permanently in ROM are called __________.
firmware
Software, such as system BIOS, stored in nonvolatile memory; can be loaded into main memory at high speeds....
peripheral devices
Storage and I/O devices in a computer, other than the CPU and primary storage.
external I/O buses
Subsidiary buses that connect external devices to the system bus; they provide the connection points for external devices and aggregate their capacity to better match a system bus connection's capacity.
MIDI
The __________ standard is a standardized method of encoding notes and instruments for communication with synthesizers and sound cards.
IEEE 802
The __________ standards define many aspects of physical networks.
Star
The __________ topology is most common in wired networks.
Control Bus
The __________ transmits command, timing, and status signals between devices in a computer system
Bus
The ___________ topology is most common in wireless networks.
Address Bus
The _________________ transmits a memory address when primary storage is the sending or receiving device
packet switching
The most common type of TDM, in which messages are divided into packets and then transmitted to their destination as channel capacity becomes available. Time-division multiplexing.
flash RAM
The most common type of nonvolatile memory; typically used to store firmware and in portable secondary storage systems, such as USB flash drives...
cyclic redundancy checking (CRC)
The most widely used error-detection method; uses a complex algorithm to generate CRC bit strings for groups of characters or bytes
Category 6
The most widely used twisted-pair wiring standard; consists of four twisted pairs that transmit at speeds up to 1 Gbps.
areal density
The number of bits per square inch of a disk platter.
chromatic depth
The number of distinct colors or gray shades that can be displayed in a grayscale image. See also grayscale.
resolution
The number of pixels displayed per linear measurement unit.
refresh rate
The number of refresh cycles per second on a video display device; normally stated in hertz. See also refresh cycle.
frequency
The number of wave cycles occurring in 1 second; measure in hertz.
H.323
The oldest and most widely used VoIP protocol suite is ____.
Ring Topology
Topology where the computers are connected on a loop or ring. Data flows in one direction only.
parity checking
Validating character data by recomputing the value of a parity.
vertical redundancy checking
Validating character data by recomputing the value of a parity.
monitor
Video display panels. The term also refers to hardware or software that tracks and reports processing or I/O activity. See also hardware monitor and software monitor.
Intermediate Nodes
VoIP equipment and software can be loosely divided into two groups: end nodes and ____.
phoneme
Vocal sounds that are basic components of human speech; they correspond roughly to the sounds of each letter of the alphabet..
Cache Hit
When a read operation accesses data already contained in the cache, it's called a(n) __________
Scan Code
When a user presses a key, the keyboard controller sends a(n) __________ to the computer.
Collision
When two messages are transmitted at the same time on a shared medium, a(n) __________ has occurred.
Internet Protocol
a packet format that defines the content of a datagram, including: - Data content - Sequencing of multiple-packet messages - Addressing and routing information
Carrier Sense
a sending node listens until no traffic is detected before attempting to transmit
message
a unit of data or information transmitted form a sender to a recipient.
coercivity
ability of an element or compound to accept and hold a magnetic charge
Star Topology
all "end nodes" are directly connected to a central node advantage: simple, maintainable wiring & central node is typically in a central wiring closet Disadvantage: if central network failed then whole network fails
Bus Topology
all "end nodes" are directly connected to a common communication channel - there is no central node advantage: simple wiring layout; no central point of failure disadvantage: channel is shared (one convo at the same time)
Socket
A __________ is the combination of an IP address and a port number.
bus slaves
Devices that must go through the bus master for access to the bus.
Bus
A __________ is the communication channel that connects all computer system components
acknowledge (ACK)
An ASCII control character sent by a receiver if no data errors are detected.
scanning laser
Devices that sweep a narrow laser beam back and forth across bar codes. See also bar-code scanner.
Forwarding Table
a list of addresses (or groups of addresses) and the node to which they should be sent
Hub
- Central connection point for LAN wiring - May implement a logical topology internally - Few or no "brains" - no routing - Rarely used today except for patch panels
Wireless Access Point
- Connects a wireless network to a wired network - Implements one or more IEEE wireless networking standards (for example, 802.11n) - Divides allocated RF bandwidth into subchannels to support multiple transmission paths and assigns nodes to specific subchannels - Implements CSMA/CA or another MAC protocol for each subchannel - Implements protocols for error detection/correction and security
Switch
- Connects each node to a full-duplex dedicated port - Forms virtual two-port networks on a per-packet basis - Larger switches can form many two-node networks at the same time
Router
- Connects two or more networks - Actively forwards packets as needed - Maintains a routing table and makes "intelligent" routing choices
Connection Oriented Protocol
- Contacts a recipient before sending data to "let it know that messages are coming" - Negotiates communication parameters such as error detection/correction, data encoding, and security - The process is like what happens when you dial a telephone number
Routing Information Protocol
- Defines how datagrams are routed from sender to receiver - Defines how routers exchange routing information
Network Interface Card
- Device that connects a single node (usually a workstation or server) to a single network (usually a LAN) - Acts as a bridge between the network and the node's system bus - Sample device on right would "plug into" an expansion slot of a desktop computer bus (see Figure 6.4) - Many computers have the network adapter integrated into the motherboard
Router
A ____ intelligently forwards messages between two or more networks.
local not local
- the central node forwards it to the corresponding directly-connected node - the central must decide to which other directly-connected node the message should be forwarded
helical scanning
...A geometric approach to recording data on a tape surface in which data is read and written by rotating the read/write head at an angle and moving from tape edge to tape edge.
read/write head
...A mechanism in a storage device that reads and writes data to and from the storage medium; also referred to as a "read/write mechanism"
static RAM (SRAM)
...Atype of RAM that is implemented entirely with TRANSISTORS; the basic storage unit is a flip-flop circuit.
magnetic decay
...The tendency of magnetically charged particles to lose their charge over time; it's constant over time and proportional to the power of the chard.
head-to-head switching time
...The time needed to switch a hard drive's read/write circuitry to the correct read/write head before accessing a sector.
sequential access time
...The time required to read the second of two adjacent sectors on the same track and platter of a hard disk.
IEEE 802
1. The __________ standards define many aspects of physical networks
Collision
1. When two messages are transmitted at the same time on a shared medium, a(n) __________ has occurred.
Serial
1. __________ transmission sends bits one at a time over a single transmission line or electrical circuit.
Connectionless
10. A receiver can't detect loss of datagrams if a(n) __________ protocol is used.
Binary
10. A(n) __________ signal is a discrete signal that can encode only two possible values.
Carrier
11. A(n) __________ wave transports encoded data through a transmission medium.
Datagram
11. In the TCP/IP model, a(n) __________ is the basic data transfer unit.
Category 6
40. __________ cable is an improved version of Category 5 cable that transmits data at high speeds more reliably.
802.11b, 802.11g, 802.11n
41. Wireless LANs following the IEEE ____________, ____________, and ____________ standards transmit in the 2.4 GHz band.
Serial Advanced Technology Attachment (SATA) and Serial Attached SCSI (SAS)
5. Serial transmission standards, including __________ and __________, are replacing parallel transmission standards for connecting secondary storage devices and controllers.
Network
5. The OSI __________ layer forwards messages to their correct destinations.
Socket
6. A __________ is the combination of an IP address and a port number.
Frequency
6. The __________ of a sine wave is measured in hertz.
Circuit
7. Most local phone service uses __________ switching to route messages from a wired home phone to the local phone-switching center.
Application
7. The OSI __________ layer refers to communication protocols used by programs, such as Web browsers, that generate requests for network services.
Star
8. A network using a physical __________ topology connects all end nodes to a central node.
Packet
8. Most networks use __________ switching to send messages from sender to receiver.
Switch, Router, Wireless Access Point (Wireless AP)
9. A physical connection between two different networks is implemented by using a(n) __________, __________, or __________.
Parity Checking
9. In __________, a bit is added to each character or byte, and the bit value is determined by counting the number of 1 bits.
scan code
A 1- or 2-byte data element generated by a keyboard controller; represents a specific keyboard event. See also keyboard controller.
parity bit
A bit appended to a character that stores redundant information used for error checking; its value is a count of other bit values in the character.
S/N Ratio
A channel's __________ describes the mathematical relationship between noise power and signal power.
Bandwidth
A channel's __________ is the difference between the highest and lowest frequencies that can be transmitted.
circuit switching
A channel-sharing strategy that grants exclusive use of a communication channel for the duration of the session.
frequency-division multiplexing (FDM)
A channel-sharing technique that partitions a single broadband channel into multiple narrowband subchannels, each representing a different frequency band.
bus clock
A clock circuit that generates timing pulses, which are transmitted to all devices attached to the system bus to coordinate their activities.
font
A collection of characters of similar style and appearance.
24-bit color
A color display scheme that represents each pixel's color as three 8-bit numbers, each representing the intensity of an additive or a subtractive color; results in chromatic depth of around 16 million colors. See also chromatic depth.
communication channel
A combination of a sending device, a receiving device, the transmission medium connecting them, and a communication protocol.
Quarter Inch Committee
A committee that develops open standards for magnetic tape drives on smaller computers...
Graphics Interchange Format (GIF)
A common bitmap compression format for still images
Joint Photographic Experts Group (JPEG)
A common bitmap compression format for still images.
Return
A communication channel using electrical signals must have at least two wires—a signal wire and a(n) __________ wire—to form a complete electrical circuit.
simplex mode
A communication mode in which messages flow in only one direction.
broadcast mode
A communication mode in which the same message is transmitted to all devices on a network simultaneously.
full-duplex mode
A communication mode in which two transmission lines are used; allows simultaneous communication in both directions.
half-duplex mode
A communication mode that uses a single shared channel, and each node takes turns using the transmission line to transmit and receive.
transmission medium
A communication path that carries signals.
I/O port
A communication pathway from the CPU to a peripheral device; in most computers, it's a memory address, or set of contiguous memory addresses, that can be read or written by the CPU and a single peripheral device.
bus protocol
A communication protocol, used by all devices attached to a bus, that governs the format, content, and timing of data, memory addresses, and control messages sent across the bus.
speech synthesis
A complex process for generating human speech based on character or text input.
composite signal
A complex signal created by combining multiple simple signals
lossy compression
A compression algorithm in which data content is altered or lost when compressed and then decompressed; usually applied only to audio and video data.
lossless compression
A compression algorithm in which data content is unchanged when compressed and then decompressed.
line turnaround
A control message that's sent when one node in a half-duplex channel has stopped sending; the receiver then assumes the role of the sender.
InfiniBand
A data connection standard for high-speed interconnection of network switches, servers, and secondary storage devices; based on a switched fabric architecture.
signal
A data transmission event or group of events representing a bit or group of bits; an message sent from one active process to another.
bus master
A device attached to a bus that can initiate a data transfer operation or send a command to another device; it controls all access to the bus.
DMA Controller
A device attached to the system bus and main memory that manages data transfers, freeing the CPU to execute instructions.
video controller
A device connected to the system bus (or a dedicated video bus) that accepts commands and data from the CPU and generates analog or digital video signals, which are transmitted to the monitor.
MIMO
A network protocol or device that supports __________ enables higher data transfer rates using multiple subchannels simultaneously or improved reliability via diversity.
organic LED (OLED)
A newer LED, manufactured with TFT technology, that achieves high-quality color display with organic compounds. See also light-emitting diodes (LEDs) and thin film transistor (TFT).
Ready to Send Signal
A node that wants to transmit a message first transmits a...
interrupt code
A numerical value of an interrupt, indicating the type of event that has occurred; usually equivalent to the bus port number of the peripheral device sending the interrupt.
DVD
AN optical disk format for distributing movies and other audiovisual content; stands for both "digital video disk" and "digital versatile disc"
negative acknowledge (NAK)
An ASCII control character sent by a receiver if data errors are detected.
packets
Basic units of data communication in a network
start bits
Bits added to the beginning of messages in asynchronous transmission to alert the receiver to synchronize its clock.
A(n) __________ is a reserved area of memory used to resolve differences in data transfer rate or data transfer unit size
Buffer
polyphonic
Capable of generating many frequencies (notes) simultaneously.
monophonic
Capable of generating only one frequency (note) at a time.
distortion
Changes to the data signal caused by interaction with the communication channel; can include echoes, resonance, and selective attenuation.
RGB
Color video display can be achieved by using elements colored __________.
QR Code
Commonly used two-dimensional bar-code formats include PDF417 and __________.
synchronous idle characters
Control messages consisting of a predetermined pattern of signal transitions designed for easy clock synchronization.
CMY
Cyan, magenta, and yellow; the primary colors in printing. See also subtractive colors.
CMYK
Cyan, magenta, yellow, and black; represents the primary colors in printing plus a separate ink for black.
Magnetic Decay
Data stored on magnetic media for long periods of time might be lost because of _________.
flat panel displays
Newer video display devices that are thinner, generate higher quality images, and consume less power than CRTs.
Clear to Send Signal
No collision, it transmits a ...
Type 1 error
Null hypothesis rejected when it is true. By definition a type 1 error can only be considered if a statistical difference is found
Port Number
Numbers at the end of IP address
track
One concentric circle of a platter; the surface area that passes under a read/write head when its position is fixed....
DVD-ROM
One of the standard optical storage media that are written only during manufacture is called __________.
Logical Accesses
Part of a device controller's function is to translate __________ into physical accesses
I/O Wait States
The CPU incurs one or more __________ if it's idle pending the completion of an I/O operation
Session
The OSI __________ layer establishes and manages connections between clients and servers.
Network
The OSI __________ layer forwards messages to their correct destinations.
Application
The OSI __________ layer refers to communication protocols used by programs, such as Web browsers, that generate requests for network services.
ARPANET
The U.S. Department of Defense sponsored the development of a peer-to-peer inter-networking standard in the late 1960s
Jitter
The VoIP user perceives ____ as periods of silence mixed with overlapped voice signals.
Presentation
The ____ layer ensures that data transmitted by one network node is interpreted correctly by the other network node.
Network
The ____ layer forwards messages to their correct destinations.
Application
The ____ layer includes communication protocols used by programs that make and respond to high-level requests for network services.
Data Link
The ____ layer is the interface between network software and hardware.
TCP/IP
The ____ model was originally intended to unite disparate network standards in a way that enabled any node connected to any type of network to communicate with any other node.
JPEG
The _____ or GIF format is commonly used to compress still images.
CSMA/CA
The __________ MAC protocol is used in wireless networks to prevent most collisions.
OSI Model
The __________ defines conceptual software and hardware layers for networks.
Bus Protocol
The __________ defines the format, content, and timing of data, memory addresses, and control messages sent across the bus
Memory Bus
The __________ has a much higher data transfer rate than the system bus because of its shorter length, higher clock rate, and large number of parallel communication lines
Read/Write head
The __________ of a hard disk drive generate or respond to a magnetic field.
Areal Density
The __________ of a magnetic or optical storage medium is the ratio of bits stored to a unit of the medium's surface area.
Frequency
The __________ of a sine wave is measured in hertz.
IPv6
The __________ protocol is an updated version with larger addresses and improved support for multicasting and multimedia data.
UPD
The __________ protocol is used with broadcast and multimedia applications when processing overhead needs are low and reliable delivery doesn't need to be guaranteed.
Data Transfer
The __________ rate is the speed at which data can be moved to or from a storage device over a communication channel.
data transfer rate
The amount of data that a storage device can move from a storage medium to computer memory in one time unit, such as one second.
MP3
The audio-encoding standard that's layer 3 of the MPEG-1 standard. See also Moving Pictures Experts Group (MPEG).
track-to-track (TTT) seek time
The average time needed to move a read/write head between two adjacent tracks. Measured in milliseconds...
block check character (BCC)
The combined parity bits from each position in a group of characters or bytes; added to the end of the block before transmitting.
fragmented
The condition of a hard disk with many programs and files scattered across it in non contiguous storage locations...
Volatile
The contents of most forms of RAM are __________, making them unsuitable for long-term data storage.
Data Transfer Unit Size
The data transfer rate of a magnetic or optical disk drive can be calculated by dividing 1 by the drive's access time and multiplying the result by the __________.
sector
The data transfer unit for magnetic disk and optical disc drives; the size is generally stated in bytes and can very from one device to another. Also refers to a fractional portion of a track on magnetic disk media...
effective data transfer rate
The data-transmission capacity actually achieved with a communication protocol; always less than the raw data transfer rate.
bandwidth
The difference between the maximum and minimum frequencies that can be transmitted through a transmission medium.
bit time
The duration of each bit in a carrier signal
read-only memory (ROM)
The earliest type of nonvolatile memory, with data content written permanently during manufacture; this primary storage device can be read, but no further data can be written...
law of diminishing returns
The economic principle stating that when multiple resources are required to produce something useful, adding more of a single resource produces fewer benefits; can be applied to buffer and cache sizes as well as many other computer system components.
PostScript
The language __________ is a commonly used image description language for documents.
Skew
The length of a parallel communication channel is limited by __________, which can cause bits to arrive at slightly different times.
supervisor
The master interrupt handler program; it examines the interrupt code stored in the interrupt register, uses it as an index to the interrupt table, extracts the corresponding memory address, and transfers control to the interrupt handler at that address.
sustained data transfer rate
The maximum data transfer rate a storage device or communication channel can sustain during lengthy data transfer operations...
raw data transfer rate
The maximum number of bits or bytes per second a communication channel can carry; ignores the communication protocol and assumes error-free transmission.
Ethernet
The original __________ standard transmits at 10 Mbps over twisted-pair cabling. Current standard versions support 1, 10, and 40Gbps transmission over twisted-pair and fiber-optic cable.
control bus
The portion of the system bus that carries commands, command responses, status codes, and similar messages; computer components coordinate their activities by sending signals over this bus.
address bus
The portion of the system bus that transmits a memory address when primary storage is the sending or receiving device.
data bus
The portion of the system bus that transmits data between computer components.
additive colors
The primary colors for video display (red, green, and blue).
CMY
The printing industry generally uses inks based on the subtractive colors, which are __________.
Dithering
The process of __________ creates an interlocking pattern of colored pixels that fools the eye into thinking a uniform color is being displayed.
Sampling
The process of __________ is converting analog sound waves to a digital representation thousands of times per second.
sampling
The process of converting analog sound waves to digital representation; it analyzes the content of the audio sound spectrum many times per second and converts it to a numeric representation.
push
The process of copying register values to the top of a stack.
speech recognition
The process of recognizing and responding to the meaning embedded in spoken words, phrases, or sentences.
pop
The process of removing register values from the top of a stack and loading them back into the correct registers.
hit ratio
The ratio of cache hits to read accesses.
compression ratio
The ratio of data size in bits or bytes before and after compression.
magnetic leakage
The reduction in strength of a stored magnetic charge because of interference form adjacent magnetic charges of opposite polarity...
machine state
The saved register values of interrupted processes or programs that represent their state before an interrupt.
linear address space
The set of sequentially numbered storage locations in a peripheral device; these locations must be converted into a disk's corresponding platter, sector, and track for the CPU to physically access the correct sector.
dual porting
The simultaneous read/write capability in video RAM.
Multicasting
The term ____ describes transmission situations involving multiple senders and receivers.
Modulation
The term __________ describes encoding data as variations in one or more physical parameters of a signal.
Scaling Up
The term __________ describes methods of increasing processing and other computer system power by using larger and more powerful computers
Rotational delay
The three components that are summed to calculate average access time for a disk drive are head-to-head switching time, track-to-track seek time, and __________.
rotational delay
The time a hard disk controller must wait for the right sector to rotate beneath read/write heads...
bus cycle
The time interval from one bus clock pulse to the next; also the time required to perform one data transfer operation on a bus.
skew
The timing difference between the arrival of bits sent in a parallel transmission channel; skew increases with distance and transmission rate.
Colon Hexadecimal
The written format of 128-bit IP addresses is called ____ notation.
Even or Odd
With parity checking, sender and receiver must agree whether error detection is based on __________ parity.
CSMA/CD
With the __________ MAC protocol, collisions can occur, but they're detected and corrected.
User Datagram Protocol
____ is a connectionless protocol that provides less reliable transport services.
Voice over IP
____ is a family of technologies and standards for carrying voice messages and data over a single packet-switched network.
Gigabit Ethernet
____ is based on the 802.3z standard and the 802.3ab standard.
TCP/IP
____ is the glue that binds private networks together to form the Internet and the World Wide Web.
Switches
____ make forwarding decisions by using layer 2 addresses.
Routers
____ make forwarding decisions by using layer 3 addresses.
Category 6e
__________ cabling meets an industry standard that specifies four twisted-pairs and can support data transmission rates up to 1 Gbps.
EMI
__________ can't affect optical signals but can affect electrical or RF signals.
Serial
__________ communication sends bits one at a time over a single transmission line or electrical circuit.
Frequency Modulation (FM)
__________ encodes data by varying the distance between wave peaks in an analog signal.
Amplitude Modulation
__________ encodes data by varying the magnitude of wave peaks in an analog signal.
Block Checking
__________ generates a(n) __________ consisting of a single parity bit for each bit position in the group of characters or bytes.
CRC
__________ is an error-detection method that treats an entire data block as a binary value divides that value by a binary key value, and appends the remainder to the data block as check data.
Distortion
__________ is any change in a signal characteristic caused by components of the communication channel.
Attenuation
__________ is loss of signal strength as it travels through a transmission medium.
Crosstalk
__________ is noise added to the signal from EMI generated by adjacent transmission lines in a parallel communication channel.
DVD-RW
__________ is one of the competing standards for rewritable DVD discs.
Magnetoresistive RAM (MRAM)
__________ is one of the promising new technologies for implementing NVM that promise significant increases in longevity.
Access Time
__________ is typically stated in milliseconds for secondary storage devices and nanoseconds for primary storage devices.
Half-Duplex
__________ mode implements two-way transmission with only one communication channel.
Full-Duplex
__________ mode implements two-way transmission with two separate communication channels.
Parallel
__________ transmission uses multiple lines to send multiple bits simultaneously.
Multilevel Coding
__________ uses more than two signal characteristic levels to encode multiple bits in a single signal.
CD-DA
__________, DVD, and BD are storage formats originally designed for music or video recording that have been applied to computer data storage.
Transmission Control Protocol
a "connection" protocol layered over IP that enables: - Detection of transmission errors - Retransmission of missing or corrupted packets
UDP
a connection-oriented protocol - "Lighter" than TCP - Less error detection - No retransmission of lost/garbled datagrams - Intended for streaming multimedia
Socket
combination of IP address and port number
Multicasting
data transmission among multiple senders and receivers
Reverse Address Resolution Protocol
describes broadcast messages that inform routers and other devices of network addresses and their corresponding IP addresses
Address Resolution Protocol
describes queries that convert IP addresses into network addresses (e.g., Ethernet MAC addresses)
Access Arm
device within a disk drive containing one or more read/write heads mounted at one end. The other end is attached to a motor that enables the read/write heads to be positioned over a single track of the disk platter
Ring Topology
every "end node" directly connected to two other end nodes
Collision
when two nodes "speak" at the same time on the same media their message combine resulting in noise
Physical Topology
how are the nodes and connections physically arranged - what is connected to what?
Logical Topology
how do messages traverse the physical network?
IP Address
is a unique 32 bit number, generally written in "dotted decimal notation"
Advanced Intelligent Tape
magnetic tape standard developed by Sony based on Digital Audio Tape technology
LANs
networks within a single floor or building
Backbone Network
provides high-speed connection among different parts of campus
average access time
statistical average (or mean) elapsed time required by a storage device to respond to a read or write command
Default Gateway
the address of a central node to which messages to "unknown" addresses are sent
Network Topology
the organization of nodes and communication channels for message transport
Collision Detection
the sending node listens for a collision during and immediately after transmitting