Power Supply, Fan • Motherboard • CPU, Co-processor • Heat Sinks • Memory Chips (RAM,ROM,CMOS) • Expansion Slots/Expansion Cards • Sound Card, Network Card, Video Card, Video Capture Card • System Clock • Buses (System and Expansion(ISA,PCI,AGP, USB and 1394 bus) • Ports (back side of system unit) • Serial, Parallel, Video,USB, USB 2.0,Midi, SCSI, Wireless,1394 or FireWire • keyboard/Mouse, Hard Drive, Monitor, Printer, other external devices • Hard Drives, Floppy Drives, Cables • Glue Chips
CPU CPU • Chip = a small piece of semi conducting material that integrated circuits are etched. An integrated circuit is a pathway capable of carrying electrical current and contains millions of transistors or gates that open or close the circuit for the signal • One of the most important ones is the CPU 8088 Chip 5 MgHz
Central Processing Unit CPU • Interprets and carries out basic instructions that operate a computer • Also calledthe processor What is the central processing unit (CPU) ?
Common Processors Intel, AMD and Motorolla • Power User: Itanium (1 Ghz and Up) or Xeon (1.4 – 2.8 Ghz) • Pentium Family • Pentium 4: 1.4 Ghz to 3.4 Ghz • Celeron (up to 2.2 Ghz) • AMD: Athlon, Duron, AMD-K6 • Motorola: APPLE • Macintosh, Power Macintosh • Digital: Alpha • Workstations and high end servers
Central Processing Unit CPU Arithmetic/Logic Unit (ALU) Control Unit What are the components of the CPU?
Central Processing Unit Control Unit What is the control unit? • Directs and coordinates operations in computer Control unit repeatsfour basic operations: • Fetch - obtain program instruction or data item from memory • Decode - translate instruction into commands • Execute - carry out command • Store - write result to memory
Central Processing Unit • Instruction time (i-time) - time taken to fetch and decode • Execution time (e-time) - time taken to execute and store e-time i-time What is a machine cycle? • Four operations of the CPU comprise a machine cycle • Also called instruction cycle
Central Processing Unit Comparison (greater than, equal to, or less than) .and. .or. .not. Arithmetic (addition, subtraction, multiplication, and division) Logical (AND, OR, NOT) What is the arithmetic/logic unit (ALU) ? • CPU component that performs execution part of the machine cycle
Central Processing Unit What is pipelining? • CPU begins executing second instruction before completing first instruction • Results in faster processing Machine Cycle (without pipelining) Machine Cycle (with pipelining) Instruction 1 Instruction 2 Instruction 3 Instruction 4
Central Processing Unit Stores instruction while it is being decoded Stores results of calculation Stores location from where instruction was fetched Stores data while ALU processes it What is a register? • Temporary storage area that holds data and instructions
Central Processing Unit MHz- one million ticks of system clock GHz – one billion ticks of system clock What is the system clock? • Synchronizes all computer operations • Each tick is clock cycle
Central Processing Unit How do personal computer processors compare?
Data Representation • Two states • Binary numbering system • ASCII (American Standard Code for Information Interchange) • EBCDIC (Extended Binary Coded Decimal Interchange Code)
Data Representation What are two popular coding systems to represent data? • ASCII - American Standard Code for Information Interchange • EBCDIC - Extended Binary Coded Decimal Interchange Code
Data Representation Step 2: Electronic signal for letter T sent to system unit Step 3: Signal changed to its ASCII code (01010100) and stored in memory Step 4: After processing, binary code for letter T is converted to image on output device How is a character sent from keyboard to computer? Step 1: Press letter T
Memory seat C22 seat A22 seat B22 What is memory? • Temporary storage area for operating system, application programs, and data • Consists of one or more chips on motherboard • Each byte stored in unique address
Memory How is memory measured? • By number of bytes available
Memory volatile memory Loses its contents when the computer's power is turned off volatile memory Loses its contents when computer's poweris turned off nonvolatile memory Does NOT lose its contents when computer’s power is turned off What are two types of system unit memory?
Memory memory module What is random access memory (RAM)? • Memory chips that can be read from and written to by processor • Most RAM is volatile • The more RAM a computer has, the faster it operates
Types of Memory • RAM • Memory chips in the system unit • Stores programs and data • Volatile • Dynamic RAM (DRAM), must be re-energized • Synchronous DRAM (SDRAM) is faster because it is synchronized to the system clock, 7.5 ns • DDR SDRAM, 3ns • RDRAM (Intel and Rambus is trying to push), DDR (owned by Rambus – better than RDRAM, but expensive, 1.25ns • Static RAM (SRAM) • Faster and more reliable than DRAM • Does not have to be re-energized as frequently as DRAM • Used for special purposes
RAM • Often smaller in size than processor chips • Packaged on circuit boards • SIMM (single in-line memory module) –old technology current computers use------ • DIMM (dual in-line memory module) • RIMM (Rambus in-line memory module • Typically SDRAM chips
Memory What is cache? • Helps speed computer processes by storing frequently used instructions and data • Also called memory cache, cache store, or RAM cache • L1 cache built in processor • L2 and L3 cache not built in processor (depends on currency) • L2 advanced transfer cache most common
Cache • Memory cache, cache store or RAM cache • Level 1 (L1), small capacity (8 Kb to 64 Kb), built directly on the processor • Level 2 (L2), external cache, on SRAM chips, slightly slower than L1 cache but has a larger capacity, 64 KB to 4 MB, newer machines L2 cache is built on the processor and called Advanced Transfer cache- these machines can also have L3 cache (external) • Machines with cache (10-40% faster) • Most current machines have 256K to 512K of cache
Memory BIOS (basic input/output system) Stored on ROM Sequence of instructions computer follows to load operating system and other files when you turn on the computer ROM is nonvolatile — Contents not lost when computer is turned off Data can only be read; cannot be modified in ROM What is read-only memory (ROM)? • Memory chips that contain data, instructions, or information that is recorded permanently
Memory Complementary metal-oxide semiconductor memory Stores information about the computer Uses battery to retain information when computer is turned off • type of disk drives • keyboard • monitor • current time and date What is CMOS?
Memory What is memory access time? • Speed at which processor can access data from memory directly • Measured in nanoseconds (ns), which is one billionth of a second • It takes 1/10 of a second to blink your eye; a computer can perform up to 10 million operations in same amount of time
Expansion Slots and Expansion Cards expansion card expansion slot What is an expansion slot? • An opening, or socket, where circuit board is inserted into motherboard • Expansion card inserted in expansion slot
Expansion Slots and Expansion Cards How are expansion cards used?
Ports mouse keyboard USB USB serial port printer (parallel port) speaker monitor microphone game port network telephone line out telephone line in FM reception svideo out cable TV • Connects external devices to system unit What is a port?
Ports byte representation for number 5 (00110101) serial transmission of data byte representation for number 5 (00110101) byte representation for number 5 (00110101) DB-9 female connector DB-9 male connector What is a serial port? • Transmits one bit of data at a time • Used to connect slow-speed devices, such as mouse, keyboard, modem
Ports byte representation for number 1 byte representation for number 3 byte representation fornumber 5 DB-25 male connector DB-25 female connector What is a parallel port? • Connects devices that can transfer more than one bit at a time, such as a printer
Ports 1394 port USB port What is a universal serial bus port (USB) ? • Connector that supports newer peripherals and plug and play • Other popular ports include 1394, MIDI, SCSI, and IrDA
PORTS USB, USB 2.0 Can connect multiple devices MIDI Connects an instrument to the system unit SCSI High speed parallel port used to connect disk drives, 7 devices can be attached 1394 (Fire Wire) Can connect multiple devices requiring fast connections Digital video camcorders, color printers, digital cameras and DVD drives
processor system bus RAM • Channel that allows devices inside computer to communicate with each other • System bus connects processor and RAM • Bus width determines numberof bits transmitted at one time • Word size determines numberof bits processor can interpretand execute at a given time What is a bus?
Buses fastest next fastest next fastest slowest memory processor PCI busexpansion slots ISA bus expansion slots What is an expansion bus? • Allows processor to communicate with peripherals
Expansion Bus • Expansion bus allows the CPU to connect to the peripheral device attached to the expansion card • ISA (Industry Standard Architecture) • Mouse, Modem, Soundcard • PCI (Peripheral Component Interconnect) • Hard Drive (4 X faster than ISA) • AGP (Accelerated Graphics Port) which is • actually a bus • Bus designed for a video card (AGP video card) • USB (Universal Serial Bus), multiple devices, • USB connects to the PCI bus
Market Tiers • Top Tier • IBM, Apple, Compaq and HP • Second Tier • Newer companies with high sales volume • Gateway, Dell, Packard Bell • Third Tuer • Smaller Start up Companies • Mail Order
Marketing Channels • Computer Retail Store • Mail Order Suppliers • Value – added Reseller • Manufacturer Direct