[PROGG] System Unit

• The system unit is a case that contains electronic components of the computer used to process data
• Drive bay(s) allow certain peripherals, mostly disk drives, to be plugged into a computer
• Power supply converts mains AC to low-voltage regulated DC power for the internal components of a computer
• Sound card is responsible for generating and recording audio, and enables users to connect analog speakers, headphones, and microphones to their computer
• Video card enables the user to view visual information on the monitor and processes data in the form of pixels, which make up images
• Processor (CPU) provides the instructions and processing power the computer needs to do its work
• Memory is primary storage (RAM) that enables users to access data that is stored for a short time
• The motherboard is the main circuit board of the system unit
• The processor, also called the central processing unit (CPU), interprets and carries out the basic instructions that operate a computer
• Processor

  The control unit is the component of the processor that directs and coordinates most of the operations in the computer. Ito yung nagbabato ng data. It controls the input and output devices. It interprets and carries out instructions contained in computer programs
• Processor

  The arithmetic logic unit (ALU) performs arithmetic, comparison, and other operations.
• Direction of Input and Output Devices sa Processor - one-way
• Direction of Memory and Storage sa Processor - bidirectional
• Processor

  For every instruction, a processor repeats a set of four basic operations, which comprise a machine cycle

  Step 1: Fetch

  Step 2: Decode

  Step 3: Execute

  Step 4: Store
• The processor contains registers, that temporarily hold data and instructions (storage device)
• The system clock controls the timing of all computer operations. The pace of the system clock is called the clock speed, and is measured in gigahertz (GHz)
• Overclocking term for increasing a component's CPU (Central Processing Unit or computer hardware) to speed up its performance. Run at a higher speed and perform more operations per second.
• The leading manufacturers of personal computer processor chips are Intel and AMD

  Intel - multimedia tools

  AMD - gaming, graphics simulation
• A processor chip generates heat that could cause the chip to burn up. Require additional cooling like thermal base, heat sinks, and liquid cooling technology
• A bus is a channel (or shared data path) through which data are passed in electronic form.
• The capacity of a bus, called bus width, is defined by the number of bits they carry at one time.
• Three types of buses link the CPU, primary storage, and the other devices in the computer system.
• Buses

  The data bus moves data to and from primary storage.
• Buses

  The control bus transmits signals specifying whether to “read” or “write” data to or from a given primary storage address, input device, or output device.
• Data Representation

  Analog signals are continuous and vary in strength and quality
• Data Representation

  Digital signals are in one of two states: on or off
• Most computers/Devices nowadays represent data using digital signals.
• The binary system uses two unique digits (0 and 1) which are bits and bytes
• Eight bits grouped together as a unit are called a byte.
• . A byte represents a single character in the computer
• Memory consists of electronic components that store instructions waiting to be executed by the processor, data needed by those instructions, and the results of processing the data
• Stores three basic categories of items:

  The operating system and other system software

  Application program

  Data being processed and the resulting information
• Types of Memory

  Volatile memory loses its contents when power is turned off, example includes RAM
• Types of Memory

  Nonvolatile memory does not lose contents when power is removed, examples include ROM, flash memory, and CMOS
• Access Time is amount of time it takes the processor to read from memory, measured in nanoseconds
• RAM chips usually reside on a memory module and are inserted into memory slots
• Memory cache speeds the processes of the computer because it stores frequently used instructions and data, these are temporary files
• Read-only memory (ROM) refers to memory chips storing permanent data and instructions (ex: firmware)
• RAM (random-access memory) is the main memory in a computer. It is much faster to read from and write to than other kinds of storage. It is a short-term memory and it is where the data is stored that your computer processor needs to run your applications and open your files.
• A PROM (programmable read-only memory) chip is a blank ROM chip that can be written to permanently

  Example: EEPROM (a type of non-volatile ROM that enables individual bytes of data to be erased and reprogrammed.)