CSC134 Computer & Information Processing - Chapter 2: System Unit

System Unit

Introduction

• Speed, capacity, and flexibility define computer power.

• Understanding system unit components is crucial.

System Unit

• System Chassis: Houses electronic components.

• System Unit: Contains electronic components and storage.

Types of System Units

• Desktops: Separate case, tower units, all-in-ones.

• Laptops: Portable, smaller, ultrabooks, gaming.

• Tablets: Mini tablets.

• Smartphones: Handheld computers.

• Wearables: Embedded computers.

Components of System Unit

• System Boards (Motherboards):

  • Control communication.

  • Connect components.

  • Data path and traffic monitor.

• Sockets & Chips:

  • Sockets: Connection points for chips.

  • Chips: Silicon circuit boards.

• Slots:

  • Connection for specialized cards.

  • Provide expansion capabilities.

• Bus Lines:

  • Pathways for communication.

Microprocessor (CPU)

• Brain of the computer.

• Components:

  • Control Unit: Executes instructions.

  • Arithmetic-Logic Unit (ALU): Performs calculations.

• Machine Cycle: Fetch, decode, execute, store.

• Microprocessor Chips:

  • Word Size: Bits processed at once (16, 32, 64).

  • Clock Speed: Processing speed.

• Multicore Processors:

  • Multiple independent CPUs.

  • Parallel Processing: Task division across cores.

• Specialty Processors:

  • Coprocessors: Improve specific operations.

  • GPU: Graphics processing.

Memory

• Holding area for data and instructions.

• Types:

  • RAM: Random Access Memory.

  • ROM: Read Only Memory.

  • Flash Memory.

• Volatile vs. Non-Volatile Memory:

  • Volatile: Loses content when power is off (e.g., RAM).

  • Non-Volatile: Retains content when power is off (e.g., ROM, Flash memory).

• RAM:

  • Holds programs and data CPU is processing.

  • Cache memory: High-speed holding area.

  • DIMM: Expansion module for additional RAM.

• Virtual Memory: Uses hardware and software to compensate for physical memory shortages.

• Memory Measurements: Kilobytes, Megabytes, Gigabytes, Terabytes.

• ROM:

  • Non-volatile, cannot be changed.

  • Contains instructions to start the computer, access memory, handle input.

• Flash Memory:

  • Combines RAM and ROM features.

  • Contains startup information (BIOS).

Expansion Slots & Cards

• Expand system capabilities.

• Examples:

  • Graphics cards.

  • Network interface cards (NIC).

  • Wireless network cards.

  • SD cards.

Bus Lines/Bus

• Pathway for data and instructions.

• Bus Width: Number of bits that can travel simultaneously.

• Types:

  • System Bus: CPU to memory.

  • Expansion Bus: CPU to other components.

Expansion Buses

• Types:

  • USB: Connects external USB devices.

  • FireWire: Connects audio/video equipment.

  • PCI Express (PCIe): Dedicated path for each device.

Ports

• Sockets for connecting external devices.

• Types:

  • Standard Ports

  • Specialized Ports

Standard Ports

• USB: Keyboards, mice, printers.

• Ethernet: High-speed networking.

• HDMI: High definition video and audio.

• Thunderbolt: High-speed connections.

Specialized Ports

• eSATA: High-speed external storage.

• MIDI: Connect musical instruments.

• Mini DisplayPort: Connect large monitors.

• VGA & DVI: Analog and digital monitors.

• FireWire: High-speed FireWire devices.

Cables

• Connect external devices to ports.

Power Supply

• Converts AC to DC power.

• Desktop: Power supply unit.

• Laptop: AC adapters.

• Tablets/Mobile Devices: Internal AC adapters, wireless charging.

Electronic Data & Instructions

• Digital Signals: On or off states (binary).

• Analog Signals: Continuous, vary in strength.

• Conversion needed from analog to digital.

Numeric Representation

• Binary System: Two digits (bits) - 0 and 1.

• Byte: 8 bits grouped together.

• Hexadecimal System: 16 digits (0-9, A-F).

Character Encoding

• Standards for representing characters.

• Types:

  • ASCII: Personal computers.

  • EBCDIC: Mainframe computers.

  • Unicode: Internet; uses 16 bits.