Computing and the Web Computer Hardware Components

Computing and the WebComputing and the WebComputer Hardware ComponentsComputer Hardware Components

OverviewOverview Basic Concepts of Computer HardwareBasic Concepts of Computer Hardware Input DevicesInput Devices Output DevicesOutput Devices Connecting DevicesConnecting Devices Primary memoryPrimary memory The Central Processing UnitThe Central Processing Unit Moving information within the computerMoving information within the computer Categories of computersCategories of computers Software applications: Tools for maintaining your PCSoftware applications: Tools for maintaining your PC

Basic Concepts of Computer Basic Concepts of Computer HardwareHardware

The need to computeThe need to compute


The need to order informationThe need to order information


The ability to store informationThe ability to store information

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. . . And interface with humanity. . . And interface with humanity


Analog Computers . . . . Analog Computers . . . .


Digital Computers . . .Digital Computers . . .


Super Computers . . .Super Computers . . .


von Neumann Computervon Neumann Computer– Program & data are stored Program & data are stored

in the same memoryin the same memory– Single program counter – Single program counter –

one instruction at a timeone instruction at a time

Input Devices CPU Output Devices

RAM

Input devices accept data and programs from the Input devices accept data and programs from the outside worldoutside world

Output devices provide results to the userOutput devices provide results to the user

Some devices are both input and outputSome devices are both input and output


Input devicesInput devices– KeyboardKeyboard– MouseMouse– Touch padTouch pad– Touch screenTouch screen– Light penLight pen– MicrophoneMicrophone– ScannerScanner– Digital cameraDigital camera


RAM


Output devicesOutput devices– Display MonitorDisplay Monitor– Hard driveHard drive– SpeakersSpeakers– Optical DiskOptical Disk– PrintersPrinters


RAM


Dual Mode Dual Mode (input & output)(input & output)

– Touch screen displayTouch screen display– Hard driveHard drive– Optical DiskOptical Disk– Network cardNetwork card– ModemModem– Zip / Jazz driveZip / Jazz drive


RAM

Connecting DevicesConnecting Devices

Direct interface to motherboardDirect interface to motherboard– Usually a “card” (NIC, Modem, Special Usually a “card” (NIC, Modem, Special

Function)Function)– Usually require special software (driver)Usually require special software (driver)

Connect via a “port”Connect via a “port”– Port is a pathway for data to go in & out of Port is a pathway for data to go in & out of

the computer from external devicesthe computer from external devices– External devices are usually referred to as a External devices are usually referred to as a

“peripheral”“peripheral”– Different types of ports have different Different types of ports have different

characteristicscharacteristics


Some of the ports:Some of the ports:– Parallel Parallel – SerialSerial– VideoVideo– USBUSB– RJ-11RJ-11– RJ-45RJ-45


Properties of portsProperties of ports– Serial vs ParallelSerial vs Parallel– Daisy chain devices (USB or SCSI)Daisy chain devices (USB or SCSI)– Speed (10M / 100M / 1G)Speed (10M / 100M / 1G)– Buffer requirements / capacityBuffer requirements / capacity

Storing Data & InformationStoring Data & Information

Three different types of storage:Three different types of storage:– Primary memory (RAM)Primary memory (RAM)– Secondary storage (Hard drive)Secondary storage (Hard drive)– Tertiary storage (removable material ie CD)Tertiary storage (removable material ie CD)

All storage has characteristics All storage has characteristics (properties)(properties)– SizeSize– SpeedSpeed– Access methodAccess method– VolatilityVolatility


Primary Storage usually called RAMPrimary Storage usually called RAM– Random access memoryRandom access memory– Electronic (no moving parts)Electronic (no moving parts)– Fastest type of storageFastest type of storage

Access time in the nanosecond rangeAccess time in the nanosecond range

– Direct access (can go directly to any location)Direct access (can go directly to any location)– Volatile form of storage Volatile form of storage – Most expensive of the three typesMost expensive of the three types– Special types of memorySpecial types of memory

ROM (read only memory)ROM (read only memory) Cache (high speed memory)Cache (high speed memory) PROM (programmable read only memory)PROM (programmable read only memory)


Secondary Storage usually hard driveSecondary Storage usually hard drive– Supports direct access at block / file levelSupports direct access at block / file level– Electronic & mechanical ( moving parts)Electronic & mechanical ( moving parts)– Slower than RAM due to mechanical aspectsSlower than RAM due to mechanical aspects

Access time in the millisecond rangeAccess time in the millisecond range

– Nonvolatile form of storage Nonvolatile form of storage – Much less expensive than RAMMuch less expensive than RAM– Usually significantly larger than RAMUsually significantly larger than RAM


Tertiary Storage usually removableTertiary Storage usually removable– More often than not it is sequentialMore often than not it is sequential– Electronic & mechanical ( moving parts)Electronic & mechanical ( moving parts)– Slower than hard drive due to mechanical Slower than hard drive due to mechanical

aspects and removable mediaaspects and removable media– Nonvolatile form of storage Nonvolatile form of storage – Cheapest form of storageCheapest form of storage– Used for archival storage, not frequently Used for archival storage, not frequently

referenced, or extremely large data setsreferenced, or extremely large data sets Good for backup purposesGood for backup purposes


CapacityCapacity– 1 byte = 8 bits1 byte = 8 bits– 1K = 1024 bytes1K = 1024 bytes– 1M = 1024 K = 1,048,576 bytes1M = 1024 K = 1,048,576 bytes– 1G = 1024 M = 1,073,741,824 bytes1G = 1024 M = 1,073,741,824 bytes– 1T = 1024 G = 1,099,511,627,776 bytes1T = 1024 G = 1,099,511,627,776 bytes

SpeedSpeed– Millisecond = Millisecond = one thousandth of a secondone thousandth of a second

– Microsecond =Microsecond = one millionth of a second; one thousandth one millionth of a second; one thousandth of a millisecondof a millisecond

– Nanosecond = Nanosecond = one billionth of a second; one thousandth one billionth of a second; one thousandth of a microsecondof a microsecond


Information RetrievalInformation Retrieval– Random Access (direct) – allows immediate access to Random Access (direct) – allows immediate access to

stored datastored data RAM / ROM (each location is directly accessible)RAM / ROM (each location is directly accessible)

– Sequential Access – requires accessing everything from the Sequential Access – requires accessing everything from the beginning of the file up to the item you wantbeginning of the file up to the item you want

VHS video tapeVHS video tape

– Pseudo-direct access – can jump to designated starting Pseudo-direct access – can jump to designated starting pointspoints

Audio CD – can directly access starting point of each song, but Audio CD – can directly access starting point of each song, but must search within the song sequentiallymust search within the song sequentially

Type of retrieval and frequency of use will determine Type of retrieval and frequency of use will determine how the data should be storedhow the data should be stored


Characteristics of different types of storageCharacteristics of different types of storage RAM RAM

– Access time: access times ranging from 80ns to 50nsAccess time: access times ranging from 80ns to 50ns– Size: PCs today can range from 256M to 1GSize: PCs today can range from 256M to 1G– Cost: depends on density 256M ~ $110 / 1G ~ $375Cost: depends on density 256M ~ $110 / 1G ~ $375

Hard driveHard drive– Access time: depends on speed – 7200rpm -- 8.9msAccess time: depends on speed – 7200rpm -- 8.9ms– Size: 160 GSize: 160 G– Cost: $110Cost: $110

Removable Storage (Zip / Jazz) [250 M Zip]Removable Storage (Zip / Jazz) [250 M Zip]– Access time: depends on interface – 40ms seek / 1.4Mbps Access time: depends on interface – 40ms seek / 1.4Mbps

xferxfer– Size: UnlimitedSize: Unlimited– Cost: $130 + cost of media (8 pack - $85)Cost: $130 + cost of media (8 pack - $85)

The Central Processing UnitThe Central Processing Unit

Multiple components within the CPUMultiple components within the CPU ALU : does arithmetic and logicALU : does arithmetic and logic Control : manages all componentsControl : manages all components Registers : used to manipulate dataRegisters : used to manipulate data Instruction Decode : figures out what the instruction Instruction Decode : figures out what the instruction

doesdoes Program Counter : keeps track of next instructionProgram Counter : keeps track of next instruction Accumulator : special register for arithmeticAccumulator : special register for arithmetic Buses : interconnect componentsBuses : interconnect components

CPU

ALU

Control

InstructionDecode

Registers

Da

ta B

us

Co

ntro

l Bu

s

Program CounterAccumulator

Instruction register

Moving information within the computerMoving information within the computer

Data bus – used to move data between componentsData bus – used to move data between components Address Bus – used to specify memory locationAddress Bus – used to specify memory location Control Bus – used to synchronize / regulate componentsControl Bus – used to synchronize / regulate components Data is moved around in bytesData is moved around in bytes Data moves either serially or in parallelData moves either serially or in parallel

– Serial data is sent one bit at a time ins sequenceSerial data is sent one bit at a time ins sequence– Parallel data is sent eight or more bits at a timeParallel data is sent eight or more bits at a time

Maximum size depends on width of the busMaximum size depends on width of the bus Pentium has a 32bit data busPentium has a 32bit data bus

The type of component determines the need for serial or The type of component determines the need for serial or parallelparallel– Keyboard & mouse are serialKeyboard & mouse are serial– Hard drive, CDrom, & Printer are parallelHard drive, CDrom, & Printer are parallel– Everything in CPU is parallelEverything in CPU is parallel

The CPU CycleThe CPU Cycle

Fetch

Decode

Execute

Interrupt

RAM

Instruction Register

Registers

The CPU CycleThe CPU Cycle

Fetch instructions from memoryFetch instructions from memory Decode instructions and fetch operandsDecode instructions and fetch operands Execute the decoded instructionExecute the decoded instruction Service device interruptsService device interrupts Repeat cycleRepeat cycle

Cycle runs at the approximate clock Cycle runs at the approximate clock speed of the CPU (more or less)speed of the CPU (more or less)

Categories of computersCategories of computers Supercomputers Supercomputers – ultimate in speed due to – ultimate in speed due to

multiple instruction executionmultiple instruction execution Mainframe Mainframe – business class computing– business class computing Minicomputers Minicomputers – multi-user system– multi-user system Workstations Workstations – single user system– single user system Microcomputers Microcomputers – contains microprocessor– contains microprocessor Palmtop Computers Palmtop Computers – between palm & – between palm &

micromicro Calculators Calculators – limited functionality– limited functionality

Tools for maintaining your PCTools for maintaining your PC Standard Windows toolsStandard Windows tools

– Defragmentation toolDefragmentation tool– Scan disk for error checkingScan disk for error checking– System Info System Info

33rdrd party tools party tools– Norton disk doctorNorton disk doctor– System MechanicSystem Mechanic

Relationship between ComponentsRelationship between Components

Run Task ManagerRun Task Manager– Examine I/O & Memory parametersExamine I/O & Memory parameters

Run msinfoRun msinfo– See what is taking up memorySee what is taking up memory

Run DefragRun Defrag– See what disk utilization looks likeSee what disk utilization looks like

Performance & Tuning aspects of Performance & Tuning aspects of ComputersComputers

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Computing and the Web Computer Hardware Components