Is 310 Midterm 2

Front 1

Speed

Back 1

Most important in differentiating primary and secondary storage

Front 2

Access time

Back 2

time required to perform one complete read or write operation

Front 3

Average access time

Back 3

when access time varies with storage location the average is of all location access times

Front 4

Block

Back 4

generic term for describing secondary storage data transfer units

Front 5

data transfer rate

Back 5

dividing 1 by the access time in seconds and multiplying the result by the unit of data transfer

Front 6

non volatile storage

Back 6

holds data without loss over long periods

Front 7

volatile storage

Back 7

cant hold data reliably for long periods

Front 8

serial access

Back 8

storage devices stores and retrieves data items in a linear, or sequential, order ie vhs

Front 9

random access or direct access

Back 9

isnt restricted to any specific order when accessing data

Front 10

parallel access

Back 10

access multiple storage locations simultaneously

Front 11

portability

Back 11

entire storage devices can be transported between computer systems or the storage medium can be removed from the storage devices and transported to a compatible storage medium on another computer

Front 12

cost

Back 12

speed, volatility, access method, portability, and capacity change this

Front 13

random access memory

Back 13

primary storage with microchip implementation with semi conductors, capability to read and write with equal speed, random access to stored bytes, words, or larger data units

Front 14

Static Ram (SRAM)

Back 14

entirely transitiors, require continuous supply of electrical power to maintain positions

Front 15

dynamic ram (DRAM)

Back 15

each bit has a transistor and capacitor, refresh automatically, cant refresh at the same time as read write

Front 16

refresh cycle

Back 16

when dram performs a refresh operation

Front 17

synchronous dram (SDRAM)

Back 17

read ahead ram that uses same clock pulse as the system bus

Front 18

double data rate (DDR)

Back 18

supports clock rate up to 1 GHz and reads or writes eight 64-bit words per clock cycle

Front 19

nonvolatile memory (NVM)

Back 19

forms of RAM with long-term or permanent data retention

Front 20

firmware

Back 20

software stored on nvm

Front 21

read-only memory (ROM)

Back 21

earliest type of nvm

Front 22

erasable programmable ROM (EPROM)

Back 22

manufactured blank, writeen with a special EPROM writer, and erased by exposure to uv light

Front 23

electronically erasable programmable ROM (EEPROM)

Back 23

can be programmed,erased, and reprogrammed by signals sent from a cpu

Front 24

flash RAM

Back 24

most common nvm, similar to DRAM in capacity and read performance, but lacks write performance. each write degrades the storage cell

Front 25

magnetoresistive RAM (MRAM)

Back 25

stores bit values by using two magnetic elements, one with fixed polarity and the other with polarity that changes when a bit is written. comparable read and write with SRAM and densitites comparable to DRAM, does not degrade like flash ram

Front 26

phase change memory (PCM)

Back 26

uses glass like compound of germanium antimony and tellurium. switches at certain heat from amorphous to crystalline and gives off different reflectivity

Front 27

read/write head

Back 27

what the wire is coiled around

Front 28

magnetic storage

Back 28

uses read/write head to generate magnetic field that is stored on a magnetic storage medium

Front 29

magnetic disk

Back 29

flat circular platters with metallic coatings that are rotated beneath read/write heads

Front 30

track

Back 30

one concentric circle of a platter/ surface area under a read/write head when its position is fixed

Front 31

cylinder

Back 31

all the tracks at a equivalent distance from the edge or spindle on all platter surfaces

Front 32

access arm

Back 32

where the read/write head is mounted

Front 33

hard disk

Back 33

magnetic disk medium with a rigid metal base

Front 34

drive array

Back 34

multiple hard disks in a single storage cabinet

Front 35

Solid state drive

Back 35

mimics a magnetic disk drives behavior but uses flash ram or other nvm devices as the storage medium and read write mechanism

Front 36

optical mass storage

Back 36

tightly focused lasers that can access a very small storage medium area, bits are stored by variations in light reflection of the medium

Front 37

bus

Back 37

shared electrical or optical channel that connects two or more devices

Front 38

peripheral devices

Back 38

reference to all i/o, storage devices

Front 39

data bus

Back 39

transmits data between computer system components

Front 40

address bus

Back 40

transmits a memory address when primary storage is the sending or receiving device

Front 41

control bus

Back 41

carries commands, command responses, status codes, and similar messages

Front 42

bus protocol

Back 42

governs the format content and timing of data memory addresses and control messages sent across the bus

Front 43

bus master

Back 43

cpu is the focus of all computer activity and takes this role

Front 44

bus slaves

Back 44

everything else not the master

Front 45

direct memory access DMA

Back 45

assumes role of bus master for all transfers between memory and other storage or i/o devices

Front 46

peer to peer bus

Back 46

any device can assume control of the bus or act as a bus master for transfers to any other device

Front 47

memory bus

Back 47

connects only the cpu and memory, higher data transfer rate than the system bus becous of shorter length

Front 48

video bus

Back 48

connects only memory and video interface

Front 49

storage bus

Back 49

connects secondary storage devices to the system bus

Front 50

external i/o bus

Back 50

connects one or more external devices to the system bus

Front 51

logical access

Back 51

read or write operation from a storage devices

Front 52

linear address space

Back 52

set of sequentially numbered storage locations

Front 53

device controller

Back 53

implement the bus interface and access protocols. translate logical accesses into physical accesses. enable serveral devices to share access to a bus connection

Front 54

i/o channel. channel

Back 54

varies from device controller in number of devices that can be controlled, variability in type and capability of attached devices. maximum communication capacity

Front 55

interrupt handlers

Back 55

os service routine to process each possible interrupt

Front 56

supervisor

Back 56

master interrupt handler program, examines interrupt code stored in the interrupt register and uses it as an index to the interrupt table

Front 57

multiple interrupts

Back 57

grouping and prioritizing when there are more than one interrupt and the cpu is busy

Front 58

stack

Back 58

mechanism that enable a program to rsume execution in exactly the same state as before an interruption is called (LIFO)

Front 59

push

Back 59

added to the stack

Front 60

pop

Back 60

adding back to the correct register

Front 61

stack overflow

Back 61

a push to a full stack

Front 62

stack pointer

Back 62

special purpose register always points to the next empty address

Front 63

buffers

Back 63

small storage areas that hold data in transit from one device to another

Front 64

buffer overflow

Back 64

buffer isnt large enough to hold a full page

Front 65

cache

Back 65

like a buffer but only used for storage device accesses larger than buffer normally

Front 66

video controllers

Back 66

enables communication between computer system and monitor, generates analog or digital video signals

Front 67

communication protocols

Back 67

rules for message and transmission

Front 68

message

Back 68

data and command content

Front 69

encoding and transmitting

Back 69

data bits can be encoded into analog or digital signals

Front 70

carrier waves

Back 70

sine wave with encoded bits

Front 71

phase

Back 71

waves cycle

Front 72

analog signals

Back 72

uses full range of carrier wave characteristics to encode continuous data values, can represent any data value within a continuum of values

Front 73

digital signals

Back 73

can contain one of a finite number of possible values

Front 74

square wave

Back 74

contains abrupt amplitude shifts between two different values

Front 75

voltage ranges

Back 75

binary signaling method using voltage ranges

Front 76

signal capacity and errors

Back 76

analog signals compared to digital are susceptible to transmission error but carry more information

Front 77

transmission media

Back 77

communication path that transports signals

Front 78

frequency

Back 78

basic measure of data-carrying capacity

Front 79

bandwidth

Back 79

difference between max and min frequencies of a signal

Front 80

electrical cabling types

Back 80

twisted pair limited bandwidth, axial offeres higher bandwidth

Front 81

optical cabling

Back 81

high bandwidth, little internally generated noise and distortion, requires amplifiers and repeaters

Front 82

parallel transmission

Back 82

uses a separate transmission line for each bit position

Front 83

serial transmission

Back 83

uses a single line to send one bit at a time, more reliable over much longer distances