M.2 - Digital Devices

Computer

• Multipurpose device that accepts input, processes and stores data, and produces an output, according to a series of stored instructions

Input

• whatever that is typed, submitted, or transmitted to the computer

Output

• result produced by a computer

Process Data

• computers do this by performing calculations, modifying documents and pictures, drawing graphs, and sorting lists of words or numbers

Central Processing Unit (CPU)

• handles the computer’s processing

Microprocessor

• CPU of most modern computers; electronic component that can be programmed to process data

• Can’t directly understand programming language (ex. C++, BASIC, COBOL, Java), so programs have to be converted into machine language that corresponds to the microprocessor’s instruction set

• Integrated circuit designed to process instructions

• Most important and usually most expensive component in a digital device

Memory

• temporary holding area for data

• Where machine language instructions for programs are held

Computer Program

• instructions that tells a digital device how to carry out processing tasks

Software

•  sets up a computer to do a specific task; when a computer runs this, it performs the instructions to carry out a task

Stored Program

• a series of instructions for computing a task can be loaded into a computer’s memory

• single most important characteristic that distinguishes computers from other digital devices (multitasking)

First Computers

• were ‘programmed’ not by software but by connecting wire circuitry in a certain way

Application Software

• type of software that is a set of computer programs that helps a person carry out a task

• Word processors, mobile apps, spreadsheet software

System Software

• type of software whose primary purpose is to help the computer system monitor itself to function efficiently

• Operating systems, CPU monitor, device drivers

Development Tools

• type of software that is used for creating software applications, websites, operating systems, and utilities

• Programming languages, Scripting languages, Debugging tools

Small Circuit Boards and Integrated Circuits

• the essence of digital electronics

Integrated Circuit

• Set of microscopic electronic circuits etched onto a thin slide of semiconducting metal

• Other Terms: Computer Chip, Microchip, Chip

Semiconductors

• substances with properties between those of a conductor (ex. copper) and an insulator (ex., wood), examples of this are silicon and germanium

System Board/Motherboard/Main Board

• Circuit board where electronic components are mounted

• Houses all essential chips and provides connecting circuitry between them

Form Factor

• Computer industry term referring to the size and dimensions of a device or component

• Component, clamshell, slate

System Unit

• Tech speak for the part of a digital device that holds the system board

Supercomputers

• Considered the fastest computers in the world at the time of construction

• Can tackle complex tasks other computers cannot

• Use: Code breaking, modeling weather systems, simulating nuclear explosions

Mainframes

• Large and expensive computer capable of simultaneously processing data for hundreds or thousands of users

• Looks like a closet-sized cabinet

• Use: Providing centralized storage, processing and management of large amounts of data

Servers

• “Serves” data to computers in a network

• About the size of a desk draw and mounted in racks of multiple servers

• Google search results are provided by servers

Personal Computers (PC)

• Designed to meet the computing needs of an individual

• Desktops, Portables, Laptops, Tablets, Smartphones

Desktops

• Fit on a desk and run on power from a wall outlet

• Keyboard is typically separate from the monitor

• Popular in offices and schools

Portables

• Run on battery power

• Components are contained in a single case for easy transportation

Laptops

• ‘Notebook Computer’; small and lightweight with a clamshell design and keyboard at the base

Tablets

• portable computing device featuring a touch-sensitive screen for input and output

Slate Tablet

• tablet configuration that has a narrow frame screen that lacks a physical keyboard

• Apple iPad

Smartphones

• Mobile devices with similar features to a tablet

• Provide telecommunications capabilities over cellphone networks

Niche Devices

• Have one thing in common; they contain a microprocessor

Raspberry Pi

• niche device that can be connected to a keyboard and screen for a full computer experience

• Only slightly larger than a deck of cards

Portable Media Players

• Handheld devices that can store and play music

• iPod Touch

Smartwatches

• Multifunctional devices that include a camera, thermometer, compass, calculator, cell phone, GPS, media player, and fitness tracker

Activity Trackers

• monitor yours steps and heart rate

Smart Appliances

• Appliances controlled by integrated circuits called microcontrollers that combine sensors with processing circuitry

• Modern refrigerators, washing machines

Intel Corporation

• World’s largest chipmaker and supplies a sizeable percentage of the microprocessors that power desktops and laptops

8086 Family

• Intel’s chip that powered the original IBM PC; set the standard for processors used today

X86

• how the standard is referred to, and processors found in today’s desktops and laptops are compatible to this

ARM Technology

• Processors based on this dominate tablet computers and smartphones

ARM Holdings

• designed ARM tech; a British tech company founded by Acorn Computers, Apple Inc., and VLSI Tech

ARM Processors

• energy efficient, an important trait for battery-powered devices

• Microsoft’s Surface tablets, Apple’s iPads and iPhones, Samsung’s Galaxy phones

Instruction Set

• Contains a collection of instructions for actions that the circuitry in a microprocessor can perform

Arithmetic Logic Unit (ALU)

• Performs arithmetic operations (addition, subtraction), and is responsible for performing arithmetic and logical operations

• Uses registers to hold the data

Registers

• What the ALU uses to hold data that is being processed

Control Unit

• fetches each instruction for the ALU

Instruction Cycle

• Process in which a computer executes a single instruction

Instruction Pointer

• Where the memory address of the first instruction is placed in the microprocessor’s control unit

Cycle

• smallest unit of time in a microprocessor’s universe; every action a processor performs is measured by this

Multi-Core Processor

• Microprocessor that contains circuitry for more than one processing unit

Serial Processing

• Processor must complete all steps in the instruction cycle before it executes the next instruction

• “Serially”- one instruction at a time

Pipeline Processing

• When a processor begins to execute an instruction before it completes the previous instruction

Parallel Processing

• Executes more than one instruction at a time and works well with today’s multi-core microprocessors

CPU Cache

• Special high-speed memory that allows a microprocessor to access data more rapidly

• Pronounced ‘cash’

Word Size

• Number of bits that a microprocessor can manipulate at one time

• Limits the amount of memory that a processor can access

Reduced Instruction Set Computer (RISC) Processor

• Performs instructions faster than a CISC (Complex Instruction Set Computer) Processor

Random Access Memory (RAM)

• Temporary holding area for data, application program instructions, and the operating system

• Higher RAM adds to the expense

• Most RAM are volatile, meaning it needs electrical power to hold data

Read-Only Memory

• Type of memory circuitry that is housed in a single integrated circuit on the system board

• Contains a small set of instructions and data called the boot loaderthat tell a digital device how to start

Storage

• Components of a digital device designed to hold data permanently

Storage Medium and Storage Device

• two main components of a data storage system

Durability

• Resistance to damage from handling and environmental factors such as dust, humidity, heat, and cold

• Can be measured in lifespan or write cycles

Dependability

• Available when needed; not subject to breakdown, malfunction, network, outages, or service interruptions

• Can be measured by mean time between failures (time a device is expected to function before failing

• Cloud time service dependability can be measured by uptime (percent of time the service is accessible)

Speed

• Rate at which data can be stored or accessed. Faster is better

• Can be measured by data transfer rate (number of megabytes per second that are read or written)

Capacity

• Amount of data that can be stored

• Usually written in gigabytes (GB) or terabytes (TB)

Cost

• Price of the storage device and media

• Usually expressed per gigabyte

Magnetic Storage Technology

• Used for desktop and laptop hard disk drives, as well as storage devices used in enterprise computing installations, and cloud services

Magnetic Storage

• Represents data by magnetizing microscopic particles on a disk or tape surface

Hard Disk Drive

• Contains one or more platters and their associated read-write heads

Hard Disk Platter

• flat, rigid disk made of aluminum or glass and coated with magnetic iron oxide particles)

Read-Write Head Mechanism

• magnetizes particles to write data, and senses the particles’ polarities to read data

Head Crash

• when a read-write head comes into contact with the platter

Access Time

• hard disk drive specification; average time it takes a computer to locate data on the storage medium and read it

Data Transfer Rate

• hard disk drive specification; amount of data a storage device can move per second from the storage medium to RAM

Optical Technology Discs

• CDs, DVDs, Blu-ray (BD)

Optical Drive

• contains a laser that directs a beam of light toward the underside of the disc

• Pits - dark spots

• Lands - lighter, non-pitted surface area

Reflected Light

• collected by a lens and converted into 0s and 1s that represent data

Compact Disc (CD)

• original CD standard was adapted for computer storage with capacity for 650 MB (74mins) of data

Digital Video Disc/Digital Versatile Disc (DVD)

• originally designed for movies but adopted by the computer industry to store data. Originally offered 4.7GB of data, and a double-layer DVD has two recordable layers that can store 8.5GB of data

Blu-ray (BD)

• designed to hold high-definition 1080p video and offering 25gb of storage per layer

Solid State Storage or Flash Memory

• Stores data in erasable, re-writable circuitry, rather than spinning on disks or streaming tape

• Once data is stored, it is non-volatile

• Cost per megabyte of solid-state storage is slightly higher than for magnetic or optical storage

Memory Card

• Flat, solid state storage medium commonly used to transfer files from digital cameras and media players to computers

• Non-volatile

Solid State Drive

• Package of flash memory that can be used as a substitute for a hard disk drive

• Installed inside the system unit and is not meant to be removed

USB Flash Drive

• Portable storage device that plugs directly into a computer's system unit using a built-in USB connector

Cloud Storage

• Storage housed on an external device that can be accessed anywhere from an internet service

• Apple iCloud, Microsoft OneDrive, Google Drive, Dropbox

Backup

• Copy of one or more files that is made in case the originals become damaged

Recovery Drive

• contains parts of the OS necessary to boot your computer and diagnose system problems after a hard drive failure or software malfunction

Copy Command

• storing copies on the same device using versioning techniques (v2, v3) to the file names

File History

• uses file synchronization to make copies of files and create a data file backup automatically

Disk Image

• Bit-for-bit copy of the data from all sectors of a hard disk

System Image

• disk imaging option from Windows that creates an exact clone of the original disk

Peripheral Devices

• Devices that are connected to the system unit of a computer

• Printers, display devices, storage devices, mice, headsets

Expansion Ports

• Ports in the system unit that expand the options for input, output, and storage

Data Bus

• Main circuits that carry data

Local Bus or Internal Bus

• part of data that runs between the microprocessor and RAM; fastest part of the data bus to keep up with the demands of the microprocessor

Expansion Bus

• part of data that stretches from RAM to various expansion ports

Hot-Plugging

• When a peripheral device is connected or disconnected while the host device is operating

USB Hub

• Inexpensive device that turns one USB port into multiple ports

• Saves wear and tear on USB ports caused by repeatedly inserting and removing USB devices

Bluetooth

• Common wireless technology for connecting peripherals

• Low-power tech so it's ideal for mobile devices that don't have big batteries

• Must be within 30 feet of each other, and is slower compared to wired connections

Device Driver

• Software that helps a peripheral device establish communication with its host device

Screen Size

• Measurement in inches from one corner of the screen diagonally across to the opposite corner