Module 2: : Processors, Memory and the Cloud

motherboard

The main circuit board inside the computer case (system unit)

• All devices need to be connected to the motherboard. 

• External devices connect to the motherboard through ports.

Hard disk (hard drive):

Contains long-term storage of the operating system, programs and files

Sound card:

• Processes audio files/data and sends it to the speakers for audio output

Graphics processing units (GPUs)

do the processing needed to display images on the screen.

• can be located on the motherboard, on a graphics card or can be integrated directly into a CPU chip

Fan

Cools internal computer components to prevent them from overheating

Battery

• Supplies power to the computer when it is not plugged into a wall outlet

  • The CPU, RAM, Cache, ROM, Adapter cards and internal BUS are described in more detail below.

The processor (central processing unit or CPU)

• brains of the computer—as it processes program instructions and does mathematical calculations. 

  • typically made to be installed in a specific device (laptop, desktop, mobile)

  • The number of cores is how many processors are contained within one CPU chip.

dual-core CPU.

A CPU with two core

multi-core CPUs.

CPUs with many cores

 Four important components inside the CPU

• arithmetic logic unit (ALU)

• control unit,

• internal cache

• bus interface unit.

The control unit

• manages and coordinates most of the operations in the computer

The ALU (arithmetic logic unit)

does mathematical calculations and comparisons

The internal cache

• acts like the RAM of the CPU.

• It contains instructions that the CPU will process next or data that has just been processed.

• Because it is inside the CPU it is faster than RAM.

The bus interface unit

• "door" of the CPU. All data enters and exits the CPU via the bus interface unit.

A machine cycle consists of four CPU operations:

• fetching data or instructions

• decoding (interpreting) the instructions

•  executing the instructions 

• storing the results in memory

Clock speed

• how fast the CPU processes program instructions. 

  • measured in gigahertz (GHz), which is how many times the system clock ticks per second.

  • One Ghz is one billion ticks per second. 

    • The higher the clock speed, the more instructions can be processed per second by the CPU.

The Internet of Things (IoT)

• refers to objects

  •  (appliances, thermostats, watches, security systems, etc.) that are connected to the Internet which allow these objects to gather, share, transmit and receive data with other online devices.

Cloud computing

• refers to an environment of servers that contain and provide access to resources (programs, files, database, etc.) that users access across the Internet.

  • provides the following benefits: accessibility, cost savings, space savings, scalability. 

Common types of cloud services are ….

• infrastructure service (IaaS),

• software as a service (SaaS)

• platform as a service (PaaS)

infrastructure service (IaaS),

• allows individuals and

  businesses to use a vendor’s hardware to manage their

  computing needs.

  • providers offer both free and paid

    service plans based on the amount of free storage,

    and some allow users to earn additional storage by

    recommending friends to use their services or by par-

    ticipating in promotional campaigns. 

software as a service (SaaS)

• that provides access to software solutions

  accessed through a browser.

  • In addition to draw- ing shapes, touching up colors, and adding filters to images, online photo editing apps allow users to access, store, and share their photos on the cloud.

• describes a model for distributing software in which a software provider hosts applications on a server and makes them available to users via the Internet. The server can be configured with additional processing or storage capabilities as needs increase. SaaS providers often deliver their applications as cloud apps. Editing projects or photos, sending email messages, and managing finances are common consumer tasks 

platform as a service (PaaS)

• cloud computing model that provides developers with a ready-made environment for developing, testing, delivering, and managing software and web applications

Modern computers are digital computers

• meaning they represent data using a series of 0s and 1s. Each 0 or 1 is called a bit (short for binary digit).

•  smallest unit of data that a computer can process.

• The amount of data a computer can store is measured in bytes:

• 1 byte = 8 bits = 1 character, number or symbol on the keyboard

• 1 kilobyte (KB) = 1,000 bytes

• 1 megabyte (MB) = 1,000,000 bytes

• 1 gigabyte (GB) = 1,000,000,000 bytes

• 1 terabyte (TB) = 1,000,000,000,000 bytes

  • The binary numbering system is used by computers to represent numbers.

three main coding systems used to represent keyboard characters:

• EBCDIC

• ASCII

• Unicode

EBCDIC

• 8-bit coding system developed for IBM mainframe computers

ASCII

• was originally a 7-bit coding system developed for PCs.

• There is now an 8-bit “extended version” of ASCII that includes extra symbols not included in the 7-bit version.

Unicode

•  universal coding standard that uses between 8 and 32 bits to represent a character.

Bits

• used to represent images.

Graphics data

• displayed by using a series of bits to represent the color of each pixel (picture element) on the monitor

pixel

• the smallest colorable area in an electronic image

  • The number of pixels used to represent an image is indicated by the screen resolution (800x600, 1024x768, etc.)

  • Because an image can contain up to 1,000,000 pixels and each pixel is normally represented by 24 bits, image files are considerably larger than text files.

Programs also uses binary code:

• The basic set of instructions that a CPU can understand is known as an instruction set. Instruction sets are normally 32-bit or 64-bit

• Each separate instruction represents commands that tells the CPU what to do next

• Programming languages such as Java and Python are converted into machine language code by language translator programs such as compilers

Random access memory (RAM)

•  memory or primary storage.

  •  location where data and portions of programs are temporarily stored until the program (or files) are closed or the computer is shut off. Essential parts of the operating system are also stored in RAM when the computer is running.

  • typically range from 8-16 GB. RAM capacity can affect how fast your computer operates.

    • When data is stored or needs to be retrieved from RAM the operating system references a specific memory address location similar to how someone opens a specific PO box to retrieve their mail. 

    • chips reside on a memory module that is inserted into a memory slot on the motherboard.

Cache

•  temporary storage that improves a computer's processing speed by storing frequently used instructions and data. 

  • Data in cache is processed faster than data located in RAM.

There are three levels of cache:

• Read-only memory chips (ROM)

• Flash memory

• Expansion cards (also known as expansion boards)

Read-only memory chips (ROM)

• contain data and programs that cannot be written over. ROM is stored on chips on the motherboard.

  • (Examples of data stored on ROM are the instructions that boot up your computer and the basic input output system (BIOS).) 

Flash memory

• type of non-volatile memory that can be erased and reprogrammed.

  • Flash memory chips can be built directly into a device (PC, cell phone, camera) or can be removable (flash cards, drives).

Expansion cards

• (also known as expansion boards) are small circuit boards that plug into expansion slots within the motherboard.

  • Expansion cards upgrade existing computer functions and allow additional devices to be attached to the computer.

    • Two common expansion boards are sound cards and video cards.

USB adapters

• have the same functionality as internal expansion cards.

  • However, they are external components that connect to the USB port of a laptop or tablet computer.

The system bus

• an electronic path within a computer (and within the CPU) over which data can travel from one component to another.

  • freeway system of the motherboard. The wider the bus, the more bits can be transferred per second and the faster the computer can process data. Buses that connect the CPU to peripheral devices (via ports or expansion slots) are called expansion buses.

  • Common expansion bus types include PCI, PCI Express, USB, and FireWire.

Ports

• exterior connectors that enable you to plug in external hardware devices.

• attached to a bus on the motherboard so that devices plugged into each port can communicate with the CPU and other computer components. 

  • Every external HW device has a connector made for a specific type of port.

Modern computers support Plug and Play

• means the computer automatically configures new devices as soon as they are installed and the computer is powered up.