Basic Structure of Computers

 Computer system consists of three main components:

  • Input: If a user types of some letters on the keyboard, the computer creates a code representing those letters to the computer.
  • Processing: The CPU determines what letter was typed by checking the code created by the computer.
  • Output: The CPU sends instructions to the graphic cards to display the letters typed, which is showed on the monitor.
Input Components:
  • Examples:
  1. Keyboards
  2. Microphones
  3. Webcams
  4. Scanners 
  5. and etc.  
  •  Storage devices such as Hard disks and CDs/DVDs.
Processing Components:
  • CPU (Central Processing Unit)
  • CPU is the computers main processing component.
  • Executes instructions from the computer's programs.
  • Modern computers are composed of two or more cores and are commonly called multicores.
  • Greater the number of cores, better the overall performance.
Output components:
  • Examples:
  1. Monitors
  2. Printers
  3. Speakers
  4. and etc.
Storage Components:
  • The more storage computer has, the better the performance.
  • Most storage components are both input and output components.
  • There are two main types of storage again:
  1. Short term storage
  2. Long term storage.
RAM (Random Access Memory)
  • This falls under the short-term storage(volatile)
  • When power to computer is gone, all of its contents are gone.
  • Also called working storage
  • If there is not enough RAM to run a program, the computer uses disk drive to supplement (virtual memory).
Virtual Memory
  • Part of disk drive can be set as virtual memory.
  • Less used data are stored in virtual memory.
  • CPU can only access code from RAM.
  • Data needed by CPU are moved to RAM.
Long Term Storage
  • Contents still remains even when power is gone (Non-volatile).
  •  Some examples can be hard disks, CDs and flash drives.
  • Stores documents and multimedia files.
Four major PC components:
  • Motherboards
  • RAM
  • Hard drive
  • BIOS/CMOS
Bus Fundamentals
  • Bus: A collection of wire carrying signals (data, address and control) from one part of a PC to another.
  • All data that goes in and out of a computer has to go through the motherboard.
Data Bus
  • Used to carry signals from RAM to CPU and vice versa or from RAM to BIOS devices.
Address Bus
  • Used to carry address signals, examples like memory locations.
Control Signals
  • Used to carry control signals, example read or write, from CPU to memory or interfaces.
Differences between Address bus and Data bus
  • The data bus carries the data to be stored while the address bus carries the location to where it is to be stored.
I/O Polling and Interrupt
  • Polling and Interrupt let CPU stop whatever it is doing and respond it to a more important task.
  • The main difference between the two is polling keeps on checking the I/O devices at regular intervals to see whether it needs CPU service or not whereas in interrupt, the I/O devices stops the task and tell the CPU that it needs CPU service.
Hard Drive Fundamentals
  • Long term storage
  • Consists of magnetic disk called "platters" and stores data in the form of magnetic pulses.
  • Stores the OS our computer loads when it boots.
Solid State Drive
  • SSDs are used in place of hard drives.
  • Uses flash memory instead of platters and will have faster access time.
  • More expensive than hard drive.
RAM Fundamentals
  • Short term storage
  • No moving parts so accessing data there is much faster as compared to hard drives.
  • The more RAM a PC has, the faster it will be.
Fundamentals of Network Communication
  • A computer network consists of two or more computers connected by some kind of transmission medium.
  • Attaching a computer to a network requires a network interface card (NIC)
  • Unique identifier assigned to NIC.

Comments

Post a Comment

Popular posts from this blog

Topic D02 Introduction to Linux

 Linux is an operating system. An operating system is software that manages all of the hardware resources associated with a desktop or laptop. The OS manages the communication between your software and your hardware. Without the OS, the software would not function. To manage files, we can use two methods: Terminal (Command Line Interface - CLI) File manager (Graphical User Interface-GUI). Some compelling uses of Command Line Interface (CLI): Commands offer more options and are flexible. Some configurations in GUI are 5 screens deep while in CLI it is just a single command. CLI loads fast and do not consume RAM as compared to GUI. There are two ways to launch CLI on Ubuntu: Go to search and type terminal CTRL + ALT + T $ sign suggests that you are working as a regular user in Linux. "#" is displayed while working as a root user. Present Working Directory Directory which is currently browsing is called the Present working directory. if we want to check the directory we are curr...
Read more

EO2-Linux Network and Process Managment

Image
Process A process is a set of instructions that is loaded in a memory.  A process in Linux is nothing but a running program. Each process will have a unique process ID (PID) and other resources, like memory and CPU time. A process can be in only one state at an instance. They can be of the following instances: Running: It is executing the code currently. Ready: It is ready to be executed but is waiting for CPU time. Sleeping: It is temporarily stopped so that other processes are finished first. Stopped: The process is stopped by the system or the user. Zombie: The execution is completed but it still has an entry in the process table. Process Management ps - report a snapshot of the current process. ps -a -- All terminals ps -e -- List of all the processes ps -o --(customer properties) ps -ao --tty, comm, pid, %mem, %cpu top - real-time process monitor that displays the information about all running processes. kill - it is used to stop a process Network Configuration ifconfig o...
Read more

Topic D01- Container Technology

  What are Containers? It can be defined as a standard package of software that bundles the code and all its dependencies so that the application is able to run quickly and reliably from one computing environment to another. It provides an infrastructure that allows application deployment to be packaged lightly and immutably. Container Image- The code, runtime, system tools, system libraries, and settings are packaged together as a container image. Linux Containers Is a set of one or more processes that are isolated from the rest of the system. All the files necessary to run them are provided from a distinct image. Linux containers are portable and consistent as they move from development to testing, and then finally to production. This makes it better to use than most development pipelines.  Linux containers help you alleviate issues and iterate faster—across multiple environments. Why should you use Linux Containers? Imagine you’re developing an application. You do you...
Read more