Components of the System Unit

1
Components of the System Unit

• David W. Bigger
• CPU 100 Fall 2005

2
The System Unit

• Case that contains electronic components of the
  computer used to process data.
• Available in variety of shapes and sizes.
• Motherboard system board
• Main circuit board of the system
• Chip small piece of semi-conducting material,
  usually silicon, on which integrated circuits are
  etched.
• Page 184

3
Processors

• CPU Central Processing Unit
• Interprets and carries out the basic instructions
  that operate a computer.
• Control Unit directs and coordinates most of
  the operations in the computer.
• Arithmetic Logic Unit performs arithmetic
  comparison and other operations.
• System Clock controls the timing of all
  computer operations.

4
Processors

• System Clock pace of clock known as clock
  speed.
• Measured by number of ticks per second
• 1 Gigahertz (1ghz) 1 billion ticks.
• Tick clock cycle
• Computers can execute more than one instruction
  per cycle.

5
Heat Sinks, Heat Pipes, Liquid Cooling

• Heat Sink
• Small ceramic or metal component with fins that
  absorbs the heat from electrical components.
• Heat pipe
• Used in mobile systems
• Liquid Cooling Technology
• Continuous flow of liquid
• Like a car radiator

6
Data Presentation

• Analog vs. Digital
• Analog is continuous wave form signals.
• Digital is on or off lt- computers
• Binary system
• Has just two unique digits, 0 and 1
• Bit smallest unit of data the computer can
  process
• 8 Bits together form a BYTE

7
Memory

• Electronic components that store instructions
  waiting to be executed by the processor.
• A kilobyte (KB) 1024 bytes
• Volatile vs. Nonvolatile
• Volatile memory needs power or it looses its
  contents
• Nonvolatile memory doesnt it is permenant.

8
RAM

• Random Access Memory
• Also called main memory
• Memory chips that can be read from and written to
  by the processor and other devices.
• Usually reside on a memory module
• Fit in a memory slot.

9
ROM

• Read Only Memory
• Memory Chips storing permanent data and
  instructions.
• CD-ROM
• CDs

10
Flash Memory

• Type of nonvolatile memory that can be erased
  electronically and rewritten.
• USB thumb drive
• Flash Memory cards in digital cameras.

11
Expansion Slots and Adapter Cards

• Expansion Slot
• Socket on the motherboard that can hold an
  adapter card.
• Expansion card enhances functions.
• Attach peripheral
• Modems, printers, scanners, keyboards, etc

12
Ports and Connectors

• Point at which a peripheral attaches to a system
  unit so the peripheral can send data to or
  receive information from the computer.
• Sometimes referred to as a Jack
• USB Ports
• Short for Universal Serial Bus
• Can connect up to 127 peripherals with a single
  connector type.

13
Ports and Connectors

• FireWire
• MIDI Ports
• SCSI
• IrDA Port Infrared Data
• Bluetooth Radio waves

14
Bays

• An opening inside the system unit in which you
  can install additional equipment.

15
Power Supply

• Component that converts the wall outlet AC power
  into DC power for the system.
• Wall 115 to 120 volts
• Computer 5 to 12 volts