Input-Output Systems in Information Tech

IT

1. Input/Output (I/O) Systems in Computer Architecture

2. Lesson Overview Understand how external devices interact with computer systems Explore I/O modules and control methods Compare Programmed I/O, Interrupt-Driven I/O, and DMA Examine modern I/O approaches and interconnection standards

3. External Devices

4. Input Devices An input device is any hardware component that is used to enter data or instructions into a computer system . In simpler terms, it allows the user to communicate with the computer . Examples of Input Devices: Keyboard – used to type letters, numbers, and commands Mouse – used to point, click, and select items on the screen Scanner – converts physical documents into digital format Microphone – records sound or voice Webcam – captures live video or images Touchscreen – allows input by touching the screen directly Game controller/joystick – used for playing games Tip to remember: Input = In → Data goes into the computer

5. Output Devices An output device is any hardware component that receives data from a computer and presents it to the user in a readable or usable form. Simply put, it shows or delivers the result of what the computer did with the input . Examples of Output Devices: Monitor – displays text, images, and videos on the screen Printer – produces a hard copy (physical copy) of documents or images Speaker – outputs sound like music, voice, or system alerts Projector – shows computer display on a larger screen or wall Headphones – outputs audio privately to the user Tip to remember: Output = Out → Data comes out of the computer for you to see, hear, or use.

6. Storage Devices A storage device is a hardware component used to store data, files, and programs —either temporarily or permanently . It allows a computer to save information so it can be accessed and used later . Types & Examples of Storage Devices: Primary Storage (Temporary) RAM (Random Access Memory) Temporarily holds data while the computer is running Data is erased when the computer is turned off Secondary Storage (Permanent) Hard Disk Drive (HDD) – stores the operating system, software, and files Solid State Drive (SSD) – faster version of HDD, no moving parts USB Flash Drive – portable device used to store and transfer files Memory Card (SD card) – used in phones, cameras, etc. CD/DVD – optical discs used to store data or media Tip to remember: Storage devices = where the data lives They allow you to save and keep information even after shutting down your computer.

7. Characteristics of External Devices

8. 1. Data Rate The speed at which data is transferred between two devices or components, usually measured in bits per second (bps), megabytes per second (MB/s), or gigabytes per second (GB/s). Purpose: Indicates how fast data moves — the higher the data rate, the faster the performance.

9. 2. Format The physical or logical design of a component or data. It refers to how data is structured, stored, or physically presented. Two main uses: Hardware format - The shape and size of a device (e.g., 2.5-inch SSD, M.2 card, USB flash drive). Data format - The structure of data (e.g., file formats like . docx , .jpg, or disk formats like FAT32, NTFS).

10. 3. Interface Type The type of connection or communication channel between two components or systems — basically, how a device connects and communicates with the computer . Purpose: Determines compatibility and speed of data transfer.

11. Input/output modules

12. INPUT/OUTPUT MODULES An I/O (Input/Output) Module is a part of a computer system that acts as the middleman between : CPU (Central Processing Unit) Memory (RAM) Input/Output devices (keyboard, mouse, printer, hard drive, etc .) It’s responsible for making sure data flows smoothly between these parts, even though they operate at different speeds and formats.

13. INPUT/OUTPUT MODULES functions Buffering Temporarily stores data so slow devices (like a printer) can keep up with the faster CPU . Example: When you print a 10-page document, your computer sends the data quickly to the printer’s I/O module, which holds it in a buffer so the printer can print at its own pace. Control Sends control signals to devices to start, stop, or manage their operations . Example: When you press “Eject” on a DVD drive, the I/O module sends the command to open the tray.

14. INPUT/OUTPUT MODULES functions Data Conversion Converts data formats so devices and the CPU understand each other. Example: A keyboard sends keypress signals in its own format, but the I/O module converts them into binary data that the CPU can process. Device Communication Protocols Follows specific “rules” so the CPU and devices can talk to each other correctly. Example: USB devices use a USB protocol, while network cards use Ethernet protocols — the I/O module handles those differences.

15. INPUT/OUTPUT MODULES functions

16. Activity

17. Essay Based on the lesson, write a well-constructed essay about external devices, including input, output, and storage devices. Your essay should be at least five (5) sentences long and should explain their uses, functions, and differences, as well as provide examples to support your explanation. Write your essay on yellow paper and send a clear picture of it in our GC.

18. THANK YOU..