Computer Hardware Components

Computer and Mobile Device Cases

• Cases protect the internal electronics of computers and mobile devices from damage.
• Cases come in various shapes and sizes.

Motherboard

• The motherboard is the main circuit board of a computer.
• Computer chips are small pieces of semiconducting material, usually silicon, etched with integrated circuits.

Processors

• The processor, or CPU, interprets and executes basic instructions to operate the computer.
• Multi-core processors have two or more separate cores on a single chip.
• Processors include a control unit and an arithmetic logic unit (ALU).
• The control unit directs and coordinates computer operations.
• The arithmetic logic unit (ALU) performs arithmetic, comparison, and other operations.
• Registers in the processor temporarily hold data and instructions.
• The system clock controls the timing of computer operations.
• Clock speed, the pace of the system clock, is measured in gigahertz (GHz).
• Leading manufacturers of personal computer processor chips are Intel and AMD.
• Processor chips generate heat, and require additional cooling solutions.
• Cooling methods include heat sinks, liquid cooling technology, and cooling pads.

Data Representation

• Analog signals are continuous and vary in strength and quality.
• Digital signals are in one of two states: on or off.
• Most computers use digital signals.
• The binary system uses two unique digits (0 and 1).
• Eight bits grouped together are called a byte, representing a single character.

Memory

• Memory consists of electronic components that store:
  • Instructions waiting to be executed.
  • Data needed by those instructions.
  • Results of processing the data.
• Three basic categories of items are stored:
  • The operating system and other programs.
  • Applications.
  • Data being processed and the resulting information.
• Each byte resides temporarily in a location in memory with an address.
• Memory size is commonly measured in gigabytes (GB).
• Volatile memory loses its contents when power is turned off.
  • RAM is an example of volatile memory.
• Nonvolatile memory does not lose its contents when power is removed.
  • Examples include ROM, flash memory, and CMOS.
• Two common types of RAM exist: Dynamic RAM (DRAM) and Static RAM (SRAM).
• Memory cache speeds processes by storing frequently used instructions and data.
• Read-only memory (ROM) stores permanent data and instructions, known as firmware.
• Flash memory can be erased electronically and rewritten.
• CMOS technology uses battery power to retain information when the computer is off.
• Access time, measured in nanoseconds, is the time it takes the processor to read from memory.

Common DRAM Variations

• SDRAM (Synchronous DRAM) is synchronized to the system clock.
• DDR SDRAM (Double Data Rate SDRAM) transfers data twice per clock cycle.
• DDR2 is the second generation of DDR.
• DDR3 is the third generation of DDR, designed for multi-core processors.
• DDR4 is the fourth generation of DDR.
• RDRAM (Rambus DRAM) is much faster than SDRAM.

Adapters

• Adapter cards enhance functions of a system unit or provide connections to peripheral devices; examples include sound cards and video cards.
• An expansion slot holds an adapter card on a desktop or server motherboard.
• Plug and Play technology enables automatic recognition of peripheral devices upon installation.
• A USB adapter enhances functions of a mobile computer or provides connections to peripheral devices.

Adapter Card Types and Purposes

• Bluetooth: Enables Bluetooth connectivity.
• MIDI: Connects to musical instruments.
• Modem: Connects to transmission media, like cable television or phone lines.
• Network: Provides network connections, such as to an Ethernet port.
• Sound: Connects to speakers or a microphone.
• TV tuner: Allows viewing of digital television broadcasts on a monitor.
• USB: Connects to high-speed USB ports.
• Video: Enhances graphics capabilities or connects a second monitor.
• Video capture: Connects to a digital video camera.

Buses

• A bus allows various devices inside and attached to the system unit to communicate.
  • Data bus
  • Address bus
• Word size is the number of bits the processor can interpret and execute at a given time.
• Types of buses:
  • System bus
  • Backside bus
  • Expansion bus

Power Supply and Batteries

• The power supply or laptop AC adapter converts wall outlet AC power into DC power.
• Mobile computers and devices can run on a power supply or batteries.
• Batteries are typically rechargeable lithium-ion batteries.