Introduction to IT Chapter 4: Computer Hardware

Introduction to Information Technology (401102)

• Chapter 4 focuses on Computer Hardware.
• IT Infrastructure has three components: Hardware, Software and Communications/Networking.
• Hardware refers to physical components like computers, screens, printers and input/output/memory/storage/processing units, peripheral devices (telephones, antennas, network cables) and communication devices.
• Software provides instructions for hardware operation.
• Communication and networking connect hardware and software components.

Hardware

• Examples of hardware include monitor, tower, speaker, mouse, headphones, microphone, keyboard and printer.
• Additional hardware includes floppy disk, CD-R/RW or DVD, hard disk, tape, communication interface, memory, I/O interface and computer.

Computer Components

• Key computer components include Storage, I/O, CPU and Memory.

I/O Panel

• Common input/output devices include keyboard, mouse, USB, LAN (networking), serial, parallel and audio.
• Physical connections and user I/O components are two ways to categorize I/O.

Keyboards

• Standard keyboards, the most common input device, have typing as primary function.
• Intensive use can lead to repetitive stress injuries (like carpal tunnel syndrome).
• Possible solutions include split keyboards, datahand keyboards (with touch-sensitive pads) and ergonomic keyboards.
• Virtual/touchscreen keyboards (touching screen or using stylus) are an alternative approach.

Pointing Devices

• Devices for moving a pointer around the screen or manipulating existing data.
• Pointing devices include mouse, trackball, track stick, joy stick, touch pad and graphics tablet (digitizer).

Scanner

• Optical Character Recognition (OCR) software is used to convert printed text into a digital format that is editable and manipulable.
• Scanning converts a printed document (page) into a bit-mapped image.
• The software analyzes light and dark areas to identify and match characters.
• Feature Extraction is a process used by OCR software to analyze characters.
• Unclear characters can be represented by special symbols.

Bar Codes and Bar Code Scanners

• Black and white bar code lines, commonly found in retail settings, are used to track inventory items like library books.

Point-of-Sale (POS) Terminals

• Computerized cash registers that often incorporate bar code scanners for faster data entry.

Optical Mark Reader (OMR)

• Special scanners for detecting pencil marks on standardized grids (like multiple-choice tests).

Magnetic Ink Character Recognition (MICR)

• Primarily used in the banking industry for processing checks.
• Special readers can quickly read, sort and route checks.

Sensors

• Devices that collect data from the environment for input to a computer.
• Examples include car air bag activation sensor and fuel mixture/pollution control sensor.

Cameras

• Digital cameras capture images using charge-coupled devices (CCDs).
• Digital video cameras can hook to computers to display and save footage.
• Film scanners digitize slide film.
• Virtual reality and holograms are applications for capturing images

Speech Recognition Devices/Voice Recognition Devices

• Voice recognition software (VRS) converts spoken words into text, using microphones.
• VRS requires user training for voice and accent recognition.
• VRS systems are often speaker-dependent, meaning they only work well with one person.

Storage

• Used by computers to store programs and information.
• Storage can be classified as magnetic (hard disk, floppy disk, ZIP disks, tape), optical (CD, DVD), and solid-state.
• Certain storage methods can randomly access data while others require sequential access.

Memory and Storage in Computers

• Memory is the functional unit that stores and retrieves information.
• The amount and type of computer memory affect the type of programs a user can run, speed and cost of processing data.

Memory Categories

• There are two basic categories of memory: Primary (Main memory) and Secondary (Auxiliary storage).
• Primary memory stores data that the CPU is actively using..
• Secondary memory stores data not currently used..

Memory Size Measurements

• Units for measuring memory sizes include bytes, kilobytes, megabytes, gigabytes, terabytes, petabytes, exabytes and zettabytes.
• Different sizes represent different amounts of information stored.

Random Access Memory (RAM)

• RAM is the computer's main memory, used for storing data and instructions currently in use.
• Access to locations in RAM is relatively fast.
• When power is lost, data in RAM is lost

Registers

• Registers are fast storage locations within the CPU.
• They hold data and instructions involved in current processing steps

Cache Memory

• A type of high-speed memory that holds frequently accessed information.
• Data is copied from main memory to cache memory for faster access..

Read-Only Memory (ROM)

• ROM is non-volatile; it retains data even when the computer is turned off.
• Useful for storing permanent instructions required during startup (boot).
• Includes varieties such as masked ROM, PROM, EPROM, EEPROM, and flash ROM.

Four Types of Primary Memory

• Registers, Cache Memory, RAM, ROM.

Hierarchy of Memory/Storage Levels

• A diagram illustrating size, and speed of different levels of memory.
• Speed and size of memory locations decreases in a hierarchy moving away from CPU.

Auxiliary, Secondary, External or Mass Storage

• A computer’s RAM is often too small for all application use.
• Two operations for Auxiliary storage include writing (copying RAM data to a storage device) and reading (copying data from the storage device to RAM).
• Secondary storage can take several forms: Magnetic (Floppy Disk, Hard Disk, Tape), Optical(CDs and DVDs) and Solid state (Flash and Solid State Memory).

Magnetic Storage

• Data is recorded using magnetic polarities (N/S) on a spinning disk.
• When reading data, magnetic polarities induce a current to represent 0s and 1s

Optical Storage

• Pits (dark areas) and lands (shiny areas) are created on a disk using a laser beam; the amount of reflected light is used to differentiate pits and lands

Compact Disk (CD)

• Types of CDs include Read-Only Memory (ROM), Recordable (R), and Rewritable (RW).
• Data is burned into the surface of CD using a laser

Magneto-Optical Storage (MO)

• Uses magnetic and optical principles for storage.
• Re-writable and more secure than other storage methods.

Solid State Storage

• Flash memory, a type of nonvolatile solid-state storage, is commonly used in devices that need to maintain data when they are not plugged in.
• Flash memory uses electronic circuits and doesn’t have moving parts, making it faster than other types of storage.

Hard Disk Structure

• A computer hard drive stores information on spinning platters.
• The read/write heads move across the platters to access data, and data can be written and/or read.

Memory

• Memory (RAM) helps computers operate faster and more efficiently.
• Types of memory include RAM, Virtual Memory and ROM.
• Types of ROM include CD-ROM and DVD-ROM.

Memory Hierarchy

• Shows how memory levels (registers, cache, main memory, auxiliary/disk) relate based on size and speed..

Storage Permanence

• Storage has different permanency levels: High (e.g., mask-programmed ROM), Medium (e.g., NVRAM), and Low (e.g., DRAM).
• Data persistence varies between high speed, cost and size..

Basic Types of RAM

• Static RAM (SRAM) uses flip-flops, holds data while power is on.
• Dynamic RAM (DRAM) uses capacitors, needs refreshing periodically..

ROM (Read-Only Memory)

• A non-volatile type of computer memory; it retains data even when the computer is turned off.
• Holds bits even after power loss.
• Used to store software programs and permanent data in embedded systems.

ROM (Read-Only Memory) (continued)

• Various types of ROM include Magnetic core memory, EEPROM, EPROM, and flash ROM.
• Examples include BIOS or Digital Cameras

Hierarchy of Computer Systems

• Hierarchical classification of computer systems based on capabilities and applications, including supercomputers, mainframes, minicomputers, workstations and microcomputers..

The Central Processing Unit (CPU)

• Acts as the brain of a computer.
• Performs computations and completes instructions..

CPU (continued)

• Has different parts: control unit, arithmetic and logic unit (ALU), and registers.
• Registers store, provide and operate on data during processing cycles.

How Does the CPU Work?

• Input/output(I/O) data and instructions are first stored in registers from keyboards, or read from a file.
• The control unit decodes the instructions.
• The ALU performs calculations on the data.
• The results are stored in registers and eventually output through I/O.

Machine Instruction Cycle Diagram (57)

• Shows how the CPU executes instructions.

Machine Instruction Cycle

• Describes how clock speed and other factors (word length, bus width, ) affect machine processing cycles per second (MIPS), also known as the clock rate.

Advancing the Chip Design

• Improvements in chip design include increasing transistor miniaturization and using improved materials.
• Advances in micro processing include improvements to instruction sets which may be complex or reduced complexity

CPU's manufactures

• Companies that manufacture Central Processing Units (CPUs) include Intel, AMD, Motorola, Cyrix, VIA Technologies and Transmeta..

Coprocessors

• Additional chips that increase processing speed, especially for floating point math.
• Allow computers to perform floating-point mathematical operations faster.

Compatible Intel Processors

• Processors made by other companies can often emulate instructions of Intel's processors.
• Several companies developed processors that are completely compatible with Intel processors, emulating instructions in their chip.

Clock Speed

• The speed at which a microprocessor executes instructions (measured in MHz or GHz).
• A higher clock speed generally means faster processing.

Dual Processors

• Computers with multiple (two) processors that work together to improve processing speed, and handling multiple tasks.

Overclocking

• Technique that increases a computer’s processor or memory speed beyond the manufacturer's rating.
• Extra computer speed causes more processing and/or memory activity in a given period, increasing the overall computing performance.

Bus System

• A group of electronic conductors that allow data to be transferred from different parts of a computer system.
• Data, addresses and control signals travel through buses

Point-to-Point vs. Multipoint Bus

• Different ways of connecting devices within a computer system, each with its own advantages and disadvantages.

Bus Interface Bridge

• Connects different computer parts with various busses.
• Types of Bridges include Host/PCI bridge, PCI bridge and AGP bus

PCI Bus

• A local bus standard developed by Intel intended for expanding computer capabilities (e.g., adding peripherals) in a compatible manner.
• Usually implemented as a 32-bit bus, and runs at clock speeds of 33 or 66 MHz.

Industry Standard Architecture (ISA) Bus

• An outdated local bus standard used in older PCs.
• Ran at clock speeds of 6 or 8 MHz.

Accelerated Graphics Port (AGP) Bus

• A high-speed interface designed for handling 3-D graphics data..
• Directly connects graphics data and memory at faster transfer speeds, compared to other computer systems.

Instruction

• Instructions are specific directions given to a computer that affect processing sequences and outcomes.
• Instructions come in formats with opcode and operands.

Instructional Elements

• OPCODE represents tasks or actions.
• OPERANDS represent source and results

CISC vs. RISC

• Different types of computer instruction sets -CISC (Complex Instruction Set Computer) has many complex instructions, while RISC (Reduced Instruction Set Computer) has a smaller set but executes instructions faster.

CISC Architecture

• Few general purpose registers and many addressing modes.
• Includes many specialized instructions that are larger in size compared to RISC architecture

RISC Architecture

• Limited addressing modes, a register-oriented instruction set, a large bank of registers, smaller instruction words, and efficient procedure calls.

CISC vs. RISC Processing

• Illustrates that CISC instructions take more processing steps than RISC instructions for equivalent task.

This quiz covers Chapter 4 of the Introduction to Information Technology course, focusing on Computer Hardware. Explore key components like storage, input/output devices, and their roles in IT infrastructure, as well as examples of various hardware. Test your knowledge on how hardware, software, and communication/networking interact within an IT framework.