Videos – Do you need to view them? Since Chapter 4, System Unit, is a more technical chapter than the first three chapters. I recommend that you do watch the video clips. It is just another means of communicating the concepts within Chapter 4. If the video clips take too long to download, you will just have to move on to the next slide. As before, view this presentation in the Slide Show View to preserve any hyperlinks and animation. I hope you find that my presentations help prepare you for the exams. Besides, a multi-media presentation like this takes a long time to create. Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS Let’s take a look inside of the box, Arr! Drive bay(s) Power supply Sound card Video card Processor Memory CIS 101: Intro to Computers Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS What is the system unit? Case that contains electronic components of the computer used to process data Sometimes called the chassis Levi Krein Associate Professor, CIS

What are common components inside the system unit? Processor Memory Adapter cards Sound card Modem card Video card Network card Ports Drive bays Power supply Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS Click to view the “How Stuff Works” Video CPU Memory Expansion Cards Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS What is the motherboard? processor chip adapter cards memory chips memory slots motherboard Expansion slots for adapter cards Main circuit board in system unit Contains adapter cards, processor chips, and memory chips Also called system board Levi Krein Associate Professor, CIS

Check out the following terms at Webopedia. Chip = A small piece of semiconducting material (usually silicon) on which an integrated circuit is embedded. A typical chip is less than ¼-square inches and can contain millions of electronic components (transistors - switch). Computers consist of many chips placed on electronic circuit boards. There are different types of chips. For example: CPU chips (also called microprocessors) contain an entire processing unit Memory (RAM) chips contain blank memory (ROM chips studied later). Short CHIP video Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS What is a CPU chip? Small piece of semi-conducting material on which integrated circuits are etched Integrated circuits contain many microscopic pathways capable of carrying electrical current Chips are packaged so they can be attached to a circuit board pin grid array (PGA) package holds processor chips Levi Krein Associate Professor, CIS

What is the Central Processing Unit - CPU Also called the processor Processor Control Unit Arithmetic Logic Unit (ALU) Control Unit Arithmetic Logic Unit (ALU) Interprets and carries out basic instructions that operate a computer Information Data Information Control unit directs and coordinates operations in computer Memory Input Devices Data Information Output Devices Information Data Information Arithmetic logic unit (ALU) performs arithmetic, comparison, and logical operations Storage Devices

Levi Krein Associate Professor, CIS What is a machine cycle? Four operations of the CPU comprise a machine cycle Step 1. Fetch Obtain program instruction or data item from memory Processor Control Unit Memory ALU Step 2. Decode Translate instruction into commands Step 4. Store Write result to memory Step 3. Execute Carry out command Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS What is pipelining? CPU begins fetching second instruction before completing machine cycle for first instruction Results in faster processing Levi Krein Associate Professor, CIS

What is a register? Temporary high-speed storage area that holds data and instructions All data must be represented in a register before it can be processed. Stores location from where instruction was fetched Stores instruction while it is being decoded Stores data while ALU computes it Stores results of calculation Levi Krein Associate Professor, CIS

Registers – Located on the CPU Levi Krein Associate Professor, CIS

What are multi-core processors? A chip with two or more separate processors A dual-core processor is a single chip that contains two separate processors A quad-core processor is a single chip that contains four separate processors Each processor on a multi-core chip generally runs at a slower clock speed, but the combined overall performance is greatly increased View a multi-core processor video. I recommend watching at least the first & last segments: Overview & How It Works Intel Video is well done!

What is the system clock? Controls timing of all computer operations Generates regular electronic pulses, or ticks, that set operating pace of components of system unit Each tick is a clock cycle Pace of system clock is clock speed Most clock speeds are in the gigahertz (GHz) range (1 GHz = one billion ticks of system clock per second) Frequently missed test item! The system clock is but one item related to computer performance Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS Moore's Law Video In 1965, Intel co-founder Gordon Moore saw the future. His prediction, now popularly known as Moore's Law, states that the number of transistors on a chip doubles about every two years. Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS State-of-the-Art For most users ? Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS Check Your Processor Select My Computer System Tasks; View System Information How are chips made? Levi Krein Associate Professor, CIS

What are heat sinks and heat pipes? Heat sink—component with fins that cools the processor on desktop computers heat sink fan Heat pipes—smaller device for notebook computers heat sink Levi Krein Associate Professor, CIS

What is parallel processing? Using multiple processors (could be hundreds or thousands of CPUs) simultaneously to execute a program faster Requires special software to divide problem and bring results together Control Processor Processor 1 Memory Processor 2 Memory Processor 3 Memory Processor…. 100s -1,000s Memory Results combined A couple of examples of parallel processing in action. Levi Krein Associate Professor, CIS

How do computers represent data? Most computers are digital Recognize only two discrete states: on or off Use a binary system to represent the two states Use Number system with two unique digits: 0 and 1, called bits (short for binary digits) Millions of Microscopic transistors on a chip Levi Krein Associate Professor, CIS p. 4.13 Fig. 4-13

Levi Krein Associate Professor, CIS What is a byte? Eight bits grouped together as a unit Provides enough different combinations of 0s and 1s to represent 256 individual characters Numbers Uppercase and lowercase letters Punctuation marks Levi Krein Associate Professor, CIS

Popular Coding Schemes for Data Representation Western European languages ASCII American Standard Code for Information Interchange 7 bit code (128 characters) PCs & Midrange servers Most frequently used code in the world EBCDIC Extended Binary Coded Decimal Interchange Code 8 bit code (256 characters) Mainframe & high-end servers Asian languages (all languages) UNICODE 16 bit code (65,000 characters) Operating systems Windows MAC OS Linux Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS End Chapter 4: Part 1 - CPU Chapter 4 - Part 2 Memory Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS What is memory? Seat #2B4 Seat #2B3 Electronic components that store instructions, data, and results (information) Consists of one or more chips on motherboard or other circuit board Each byte stored in unique location called an address, similar to seat numbers on a passenger train Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS How is memory measured? By number of bytes available for storage Current computers typically have 2 – 8 gigabytes of memory Levi Krein Associate Professor, CIS

What is random access memory (RAM)? Memory chips that can be read from and written to by processor Also called main memory or primary storage Most RAM is volatile, it is lost when computer’s power is turned off The more RAM a computer has, the faster it responds Levi Krein Associate Professor, CIS

What are three basic types of RAM chips? Does not have to be re-energized as often; expensive Most common type Dynamic RAM (DRAM) Used for special applications such as cache Static RAM (SRAM) Faster variations of DRAM are SDRAM and RDRAM Synchronized to the System Clock Faster and more reliable than DRAM chips Rambus – faster than SDRAM; use pipelining techniques Magnetoresistive RAM (MRAM) Uses magnetic charges to store data instead of electric charges, such as those used in SRAM and DRAM technologies. MRAM will retain data even when the power is turned off . Levi Krein Associate Professor, CIS

Where does memory reside? dual inline memory module Resides on small circuit board called memory module RIMMs hold RDRAM chips SIMM & DIMMs hold SDRAM chips Memory slots on motherboard hold memory modules memory chip memory slot Memory Levi Krein Associate Professor, CIS

How much RAM does an application require? Software package typically indicate the minimum RAM requirements For optimal performance, you need more than minimum specifications System Requirements Windows® XP Home Edition/Professional Intel Pentium processor at 233MHZ or higher AMD K6 (Athlon Duron Family processor at 233MHZ or higher 64 MB of RAM Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS What is cache? A portion of memory made of high-speed static RAM (SRAM) instead of the slower and cheaper dynamic RAM (DRAM) used for main memory. Memory caching is effective because most programs access the same data or instructions over and over. By keeping as much of this information as possible in SRAM, the computer avoids accessing the slower DRAM. Also called memory cache Cache memory video Levi Krein Associate Professor, CIS

What are the different kinds of cache memory? L1 cache built into processor L2 advanced transfer cache is slower than L1 cache, but much larger capacity; built directly on processor chip; when discussing cache, most users are referring to L2 cache Advanced transfer cache significantly increases the performance of a computer L3 cache is separate from processor chip on motherboard (L3 is only on computers that use L2 advanced transfer cache) Levi Krein Associate Professor, CIS

What is Read Only Memory? Read-only memory (ROM) refers to memory chips storing permanent data and instructions Unlike main memory (RAM), ROM retains its contents even when the computer is turned off. ROM is referred to as being nonvolatile, whereas RAM is volatile. Most personal computers contain a small amount of ROM that stores critical programs such as the program that boots the computer. Firmware is software (programs or data) that has been written onto read-only memory (ROM). A PROM (programmable read-only memory) chip is a blank ROM chip that can be written to permanently EEPROM electrically erasable programmable read-only memory that can be erased by exposing it to an electrical charge. Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS What is flash memory? A specific type of EEPROM that can be erased and updated/reprogrammed. Used with many mobile devices: The flash memory can be built into the device or on removable memory cards PDAs, digital cameras, digital cellular phones, music players, digital voice recorders, pagers, and thumb drives Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS What is access time? Amount of time it takes to locate, read, and transfer data from memory making it available for processing. Very fast, measured in nanoseconds (ns), one billionth of a second 1 blink = 1/10 of a second = 10 million computer operations Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS End Chapter 4: Part 2 - Memory Chapter 4 – Part 3 Expansion Slots Adapter Cards Ports Buses Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS What is an adapter card? Types of Adapter Cards Also called an expansion card A circuit board that enhances the computer system or provides connections to external devices called peripherals Expansion cards fit into expansion slots Removing expansion card Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS What is Plug and Play? Refers to the ability of a computer system to automatically self-configure expansion boards and other devices The user does not need to worry about setting switches, jumpers, and other configuration elements. Levi Krein Associate Professor, CIS

What is removable flash memory? A PC card adds memory, sound, modem, and other capabilities to notebook computers A flash memory card allows users to transfer data from mobile devices to desktop computers A USB flash drive for storage plugs into a USB port Hot plugging allows you to insert and remove cards while the computer is running Levi Krein Associate Professor, CIS

What are ports and connectors? A port connects external devices to the system unit There are many different types of ports Connector device physically joins cable to peripheral Available in one of two genders: male and female Levi Krein Associate Professor, CIS

What are different types of ports and connectors on your computer? Very popular! Levi Krein Associate Professor, CIS USB & Firewire

What are USB ports? USB (universal serial bus) port can connect up to 127 different peripherals together with a single connector type PCs typically have two , four or more USB ports on front or back of the system unit A single USB port can be used to attach multiple peripherals in a daisy chain or via a hub Third USB device connects to second USB device, and so on Second USB device connects to first USB device First USB device connects to USB port on computer Daisy Chain Levi Krein Associate Professor, CIS

What are special-purpose ports? Allow users to attach specialized peripherals (digital video cameras, color printers, scanners, disk drives, etc.) or transmit data to wireless devices FireWire high speed port 40+ times faster than USB MIDI (Musical Instrument Digital Interface) port SCSI (small computer system interface) high speed port IrDA (Infrared Data Association) line-of-sight port BluetoothTM (wireless - short range radio waves) port Wi-Fi is a wireless technology that provides high-speed Internet and networks connections Digital cameras; USB & FireWire may replace all other ports! BIG trend! In the office; keyboards, printers, etc. Very popular Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS What is a bus? When referring to a PC, it is a data path or channel (wires or circuit) that allows devices inside the computer to communicate with each other System bus connects processor and RAM Bus width determines number of bits transmitted at one time Word size is the number of bits processor can interpret and execute at a given time Levi Krein Associate Professor, CIS

Types of expansion buses? Expansion slots connect to expansion buses Common types of expansion buses include: PCI bus PCI Express bus Accelerated Graphics Port USB and FireWire bus PC Card bus

What is an expansion bus? Allows the processor to communicate with peripherals AGP = 3-D graphics System Bus = high-speed; connects RAM to processor (not an expansion bus) PCI (local bus) = connects high-speed devices (SCSI cards, hard drives, sound cards, network cards; 4X faster than ISA) ISA = older bus technology, rapidly becoming obsolete Levi Krein Associate Professor, CIS

Levi Krein Associate Professor, CIS What is a bay? Open area inside system unit, the space is used to install additional equipment Drive bays typically hold: Disk drives DVD/CD drives Levi Krein Associate Professor, CIS

Putting It All Together What are suggested processor, clock speed, and RAM requirements based on the needs of various types of users? Intel Core 2 Duo or Intel Celeron Dual Core or AMD Sempron Minimum RAM: 2 GB Home Intel Core 2 Quad or Intel Core 2 Extreme or AMD Athlon FX or AMD Athlon X2 Dual-Code Small Office/ Home Office Minimum RAM: 4 GB Intel Core 2 Extreme or AMD Turion X2 Mobile Buy one of these! I prefer the Core 2 Quad Minimum: Core 2 Duo

Levi Krein Associate Professor, CIS Chapter 4 Complete Video - The Apple Macintosh now uses an Intel processor! Levi Krein Associate Professor, CIS