Computer Hardware and Architecture

Hardware

• This chapter reviews computer architecture.
• It also goes over input and output devices, data storage, and network hardware.

Computer Architecture

• CPU carries out instruction and processes data
• Consists of a CU an ALU, registers and buses.
• A microprocessor contains an ALU and CU so it can interpret and execute all instructions and arithmetic operations

Von Neumann Architecture

• Stored program computer where:
• There is a CPU/processor.
• A processor can access memory directly.
• Computer memory stores programs and data
• Stored programs contain instructions executed sequential order.

CPU Components

• Arithmetic and Logic Unit (ALU): executes arithmetic and logic operations, can contain multiple ALUs.
• Control Unit (CU): reads instructions, generates signals, synchronizes data flow.
• Registers: high-speed memory within the CPU, storing data and instructions.
• System Clock: Produces timing signals.
• System Buses: transfer data and control signals.

Types of Buses

• Address Bus: unidirectional, carries memory addresses.
• Data Bus: bidirectional, carries data between CPU, memory, and I/O.
• Control Bus: bidirectional, carries control signals from the control unit.
• Data/address bus width determines word length and computer performance

Memory

• Random Access Memory (RAM): Known as Immediate Access Store (IAS) and is used to hold data and instructions.
• Read-Only Memory (ROM): Cannot be altered but contains start-up routines.

Fetch-Decode-Execute Cycle

• Used by the CPU to execute instructions; it fetches data and instructions from memory and stores them in registers.
• Components used include: address bus, and data bus
• Involves fetching, decoding, and executing each instruction in sequence.

Cores, Cache, Internal Clock

• Clock cycle: Defined by system clock that synchronizes all computer operations.
• Clock speed: increasing it generally increases processing speed.
• Address/Data Bus Width: Increasing it increases processing speed.
• Overclocking: can cause overheating and system crashes.
• Cache: stores frequently used instructions to speed up CPU performance.
• Cores: improve CPU performance; quad-core processors have four units that can read and execute instructions independently.

Instruction Set

• Operations for decoding in sequence that make up an opcode and an operand
• Opcode: what operation to do
• Operand: data to act on or registers for memory

Embedded Systems

• Combined hardware and software designed for a specific task.
• Can be based on a SOC, microprocessor or microcontroller
• Microcontrollers are CPUs with RAM, ROM and peripherals on a chip/
• Microprocessors are CPUs only w/ no processing.
• Can be non-programmable or programmable

Pros of Using the Hardware System

• They are easy to fit into devices
• Low cost to make
• They are often dedicated to on task with is great for simple interfaces or OS
• Consumes little power

Cons of Using the Hardware System

• Hard to update to use latest technology
• Troubleshooting can be difficult
• Can be confusing with simple interfaces
• Can be hacked
• Throw away society due to not fixing it

Inputs and Outputs

• Examples include: security, set-top boxes, lighting, vending machines, washing machines, motor vehicles.

Input Devices

• Devices include: barcode scanners, QR scanners, digital cameras, mouse, microphone, 2D/3D scanners

Barcode Readers

• Use red light and are series of thin/dark lines that represent digits 0-9
• Used to scan to label items that uniquely identify details
• Have data in a product database

Pros of Using Barcodes

• Easy to change prices
• Great up to date stock/sales
• Reduce time and cost to manage
• Possible to check customer habits by connecting barcodes to customer loyalty cards.

Cons of Using Barcodes

• Faster checkouts for customers
• Reduced Errors
• Better sell by dates tracking

QR Codes

• Made of filled dark squares on a bright background with three large squares on the corners.
• Allows users to advertise projects and access website
• Read by camera that is processes in the a stored app

Pros of QR Codes

• Easy to transmit
• Cheaper/easier read
• Can store more info
• There are few erors due to built in error checkers

Cons fo QR Codes

• They can transmit malicious code via attagging due to mass number of free apps.
• There is more than one QR format

Digital Cameras

• Easily transfer to USB bluetooth through micro-processors
• Camera functions include; shutter speed, focus, aperture, red eye removal etc
• Tiny lenses let them be used in cars, endoscopes, and drones
• Use photodiodes captured in image through the lens

Keyboards

• USB, physical bluetooth, touchscreen
• entry is slow/prone to errors that are associated with repetitive strain injuries
• Entry of data via a keyboard is a slow process which is also prone to error and can lead to injuries such as repetitive strain injury (RSI).
• Computers are able to determine what keys were selected with ASCII values.

Microphones

• Used as sensors to defect sound and text to computers or presentations
• Convert sound into electric currents or data that is then stored to memory

Optical Mouse

• Moves on screen cursor so users can select option to move
• Uses tiny camera with light to calculate potion
• DO not have moving parts but are USB, or bluetooth connected but can work on any surface

Pros of Using Optical Mouse

• Has no moving parts
• Does not get clogged
• Does not need extra software

Cons of Using Optical Mouse

• Wired is cheaper
• Is reliable
• Has few enviormental issues

2D Scanners

• Used to scan documents to edit in work process
• Can also be used in airports to confirm identity.
• This is knows as facial recognition.

3D Scanners

• Produce 3D object data for output
• use lasers, x-rays, magnetic resonance, or white light.
• Can work with CAD or 3D print.

Tochscreens

• Touch screen has resistive, infrared and capacitive technologies.
• Capacitive technology reads the change in electric fields caused by the touch
• Resistive reads the change in touch between two layers of material
• Infrared reads a lack of signal when it interacts with something and then calculates coordinates

Output Devices

• Actuators: Used to start/stop the conveyor belt or open/close the value.
• mechanical or electrmomagnatic devices that run on relays/motors for solenoids.
• Light projectors project light output on displays, typically digital light/liquid crystal.

Types of Projectors

• LCD Projectors: Use red, blue and green components with the light beamed together to a prism.
• DLP Projectors:
• Smaller and lighter than Liquid Crystal Display projector's.
• Use mirrors arranhed on chip of DMD

Advantages of Digital Light Projectors

• High contrast ratio and greater reliability.
• They function quiety.
• These are lighter than LCD.
• Uses single DMD chip and the dust does not effecs LCD better than other options.

Disadvantages of Digital Light Projectors

• The images are not as sharp as other options.
• May have shadows
• Do not have grey component in the image

Printers

• Inkjet, or laser printers are used for common prints

• thermal bubble is used using liquid ink

• Or piezoelectric to output colored images

• Laser printers use dry powder with negatively charged drum.

3D Printers

• Based on ink jet and uses direct 3D printing to run the printing
• Can be used for direct/Binder 3D prints.
• Material include powered resin ,metal paper etc

LED/LCD Screens

• Red and Green light output is used form light emitting didoes
• Liquid crystals is used to product certain amount of color that varies in propertied due to electricity
• LED's are used to produce the back-light due to the brghness

Pro s fo LED backlight

• Brigness
• Consumes Little Power
• Almost Indefintie

OLED

• It Is 2mm or less for thickness
• Consumes less power
• Bright colors and true blacks

Speakers

• Produce sounds from elecrtic signals where the sound is sotred digitally a DAC is used,
• Speakers have cone platic and magnet that converts it to vibrations which is the soudn is produced

Sensors

• Readd physical props from surroundign by passing signals tot heat

• Sensors constantly sends signal to microprocessor

• If computer is monitoring then the output is used to alerted based from levels is a river and hospital system.

• COntrol data si often sent and DAC as well in many cases

• There are many types of sensors that measure different thigs such as temp, light, humidity.

• They use invisible beam of infrared radiation picked up by the doctor. This can be active/pasisve to send the signals