Computer Functions & Components

• Computers include workstations, network servers, and specialized devices like routers and switches.

Basic Functions of a Computer

• Input: Sends data to the computer (e.g., typing 'A' on a keyboard).
• Processing: The CPU interprets the input.
• Output: Displays the result (e.g., showing 'A' on the monitor).

Input Components

• Common input devices: keyboards, microphones, webcams, scanners.
• External interfaces: serial, FireWire, and USB ports.

Storage Components

• Storage devices: hard disks, CDs/DVDs, and USB flash drives, function as both input and output.
• More storage generally leads to better computer performance.
• Storage is divided into short-term and long-term types.

Processing Components

• CPU (Central Processing Unit) is the main processing component.
• Modern CPUs have multiple cores.
• Multicore CPUs enable simultaneous instruction execution, enhancing performance.

Output Components

• Monitors, printers, storage devices, network cards, and speakers.
• External interfaces are output components.

RAM: Short-Term Storage

• Short-term storage (RAM) is volatile, losing data when power is off.
• RAM is crucial for efficient computer operation and known as "working storage."
• Insufficient RAM leads to the use of disk drive as supplement.

Virtual Memory

• Part of disk storage can function as virtual memory.
• The CPU accesses data only in RAM; less-used data is moved to virtual memory on the hard disk.
• Data needed by CPU is moved from virtual memory to RAM.

Long-Term Storage

• Long-term storage is non-volatile and maintains data without power.
• Examples: hard disks, CDs/DVDs, USB flash drives.
• Stores documents, multimedia files, applications, and OS files.

Personal Computer Hardware

• Four main PC components: motherboard, hard drive, RAM, BIOS/CMOS.

The Motherboard and Its Components

• All data goes through the motherboard.

Component | Description

• ---------|----------- CPU socket | CPU installed in this socket. PCI bus expansion slots | Adding cards with PCI connectors allows additional functionality. PCI-Express expansion slots | Faster data transfer speeds than PCI. Larger slots suit graphics cards and disk controllers; smaller slots suit sound cards and network interface cards. RAM slots | RAM installation. Chipset with heat sinks | Northbridge and Southbridge chips control data transfers between memory, I/O devices, expansion slots, and the CPU. Heat sink prevents overheating. SATA connectors | Connecting hard drives and CD/DVD drives using Serial AT Attachment (SATA). IDE connector | Connecting IDE hard drives and CD/DVD-ROM drives. SATA is primarily used for hard drives, IDE for CD/DVD-ROM drives. Main power connector | Motherboard receives power from the system power supply.

Computer Bus Fundamentals

• Bus: A collection of wires carrying data, address, or control signals.
• Buses exist between the CPU and RAM, disk drives, and expansion slots.
• Buses carry data signals, address signals, and control signals.
• The data bus carries data, and the address bus carries the storage location.

I/O Polling and Interrupt

• Polling: The CPU regularly checks I/O devices for service requests.
• Interrupt: The I/O device alerts the CPU when service is needed.
• Both polling and interrupt enable the CPU to respond to tasks, maintaining operation of the many devices

Hard Drive Fundamentals

• Hard drive: Primary long-term storage.
• It stores documents, applications, and the operating system.
• Hard drives use magnetic disks (platters) to store data as magnetic pulses.

Solid State Drives (SSDs)

• SSDs replace hard drives due to speed and reliability.
• SSDs use flash memory.
• SSDs have no moving parts and faster access times.
• SSDs are more expensive than hard drives.
• Often found in mobile devices and high-performance systems.

BIOS/CMOS Fundamentals

• BIOS (Basic Input/Output System): Instructions located on a chip on the motherboard.
• The BIOS instructs the CPU when power is applied, including performing a power-on self-test (POST).
• Computer boot gives opportunity to run Setup utility to configure hardware (stored in CMOS).

Computer Boot Procedure

• Power is applied to the motherboard.
• The CPU starts.
• The CPU executes BIOS startup routines, including POST.
• Boot devices are searched.
• The OS is loaded into RAM.
• OS services are started.

The Fundamentals of Network Communication

• Computer network: Two or more computers connected by a transmission medium.
• Internet access requires network connectivity.

NIC Basics

• A network interface card (NIC) is required to connect to a network.
• The NIC contains a unique MAC address.
• Networking medium: copper wire, fiber-optic cable, or airwaves.

Wireless NICs

• Wireless NICs connect using a set identifier (SSID).
• Security key or username/password may be required based on security configuration.
• Wireless standards: Wireless-n, 802.11ac, or 802.11 a/b/g/n.
• Wireless NICs must be chosen according to the type of wireless AP being used.

Types of Computers

• Five main types: embedded computers, personal computers, servers and enterprise systems, supercomputers and grid computers and "Cloud" computing.
• CPU (Central Processing Unit) known as the Processor, is the core of the computer.