3-2
Microcomputer Systems
Personal Computer (PC) – microcomputer for use by an individual
Desktop – fit on an office deskLaptop – small, portable PCWorkstation – a powerful, networked PC for
business professionalsNetwork Server – more powerful
microcomputers that coordinate telecommunications and resource sharing in small networks
3-3
Terminals
Devices that allow access to a networkDumb terminals – keyboard and video monitor
with limited processingIntelligent terminals – modified networked PCs
or network computers
3-4
Information Appliances
Hand-held microcomputer devicesPersonal digital assistants (PDA)
BlackBerryVideo-game consolesInternet enabled cellular phones
3-5
Midrange systems
High-end network serversMinicomputers for scientific research and
industrial process monitoring Less costly to buy, operate and maintain than
mainframe
3-6
Mainframe Computer Systems
Large, fast powerful computer systemsLarge primary storage capacityHigh transaction processingComplex computations
Can be used as superservers for large companies
3-7
Supercomputer Systems
Extremely powerful systemsScientific, engineering and business
applications at extremely high speedsGlobal weather forecasting, military defenseParallel processing with thousands of
microprocessorsBillions of operations per secondMillions of dollars
3-8
Computer System hardware functions
InputConvert data into electronic form
Processing - Central Processing Unit (CPU)Arithmetic-logic unit performs the arithmetic
functionsControl unit
OutputConvert electronic information into human-
intelligible formStorage
Primary Storage Unit or MemorySecondary Storage: Magnetic disks and Optical disks
3-9
How corporate buyers choose PCs
Solid performance at a reasonable priceOperating system readyEnough storage capacityConnectivity – reliable network
interface or wireless capability
3-11
Computer Storage FundamentalsBinary representation
Data are processed and stored in computer system through the presence (1) or absence (0) of signals
Bit (short for binary digit)Smallest element of dataEither 0 or 1
ByteGroup of eight bits which operate as a single unitRepresents one character
3-13
Measuring storage capacitiesKilobyte (KB): one thousand bytesMegabyte (MB): one million bytesGigabyte (GB): one billion bytesTerabyte (TB): one trillion bytes
Processing/Clock speed of CPU:Megahertz (MHz) – millions of cycles/instructions
per secondGigahertz (GHz) – billions of cycles/instructions
per second
3-14
Two types of semiconductor memory
RAM: random access memoryMost widely used primary storage mediumVolatile memoryRead/write memory
ROM: read only memoryFrequently used programs burnt into chips
during manufacturingCan be read but cannot be overwrittenCalled firmware
3-15
Radio Frequency Identification (RFID)
Tag and identify mobile objectsE.g., store merchandise, postal packages, pets
Use RFID chips to transmit and receive radio signals
Chips half the size of a grain of sandPassive chips:
do not have power source and derive power from signal in reader
Active chips: Self-powered