Components of the Computer Study Guide

Backside bus

connects the processor to the cache.

The arithmetic logic unit

A component of the processor that performs arithmetic, comparison and other operations. An example would be calculation employee pay: regular vs. overtime.

Processor Cooling

A main fan is included in the main power supply of a computer to generate airflow, however, today's computers processors often require additional cooling. Heat sink is is a small ceramic or metal component with fans on its surface that absorbs and disperses heat produced by electrical components. Liquid cooling technology uses continuous flow of fluids like water or glycol to reduce the temperature of the processor by transferring the heated fluid away from the processor to a radiator-type grill which then cools the liquid and returns it cooled to the processor. Cooling pad is an item that you can purchase to place below your laptop to protect the computer from overheating. Some can include a small fan drawing power from a USB port.

Batteries

Batteries are generally rechargeable lithium-ion batteries. Not all batteries are removable, especially when referring to ultrathin laptops and some mobile devices.

SIMMs

SIMMs (Single Inline Memory Module) which has pins on opposite sides of the circuit board that connect together to form a single set of contacts.

Registers

Small high-speed storage locations contained in the processor that temporarily hold data and instructions.

Adapters

The circuitry in today's computers generally integrates all necessary functionality, but some still require additional capabilities in the form of adapters. Desktops and servers use adapter cards and mobile devices use USB.

Port and types of ports

The exterior of the computer to which a device may be attached using a connector. Types of ports: Monitor port,network port,modem port,USB port,Firewire (IEEE 1394) port, keyboard port,SCSI (small computer system interface)port, MIDI port, audio port

Motherboard

The main circuit board of the computer. The processor,memory and other components attach to the motherboard.

Gigahertz

one billion ticks per second.

System Bus

part of the motherboard connecting the processor to the main memory

Front side bus

part of the motherboard connecting the processor to the main memory.

Chassis

the case on a desktop that contains and protects the motherboard, hard drive, memory and other electronic components.

Executing

the process of carrying out the commands

Gigabyte

Approximately 1 billion bytes.

Terabyte

Approximately 1 trillion bytes.

Addressable memory

An address is a unique number that identifies the location of a byte in memory. To access data or instructions, the computer reference the addresses that contain bytes of data.

The system clock

A small quartz circuit that controls the timing of all computer operations. The system clock generates regular electronic pulses, or ticks that set the operation pace of components of the system unit.

Memory access time

Access time is the amount of time it takes the processor to read data, instructions and information from memory. Access time directly affects how fast the computer processes data; accessing data in memory can be 200,000 time or more faster than accessing data on a hard disk. A variety of terminology is used today to state access times; some using fractions of a second.

Cache

Cache is a temporary storage area.

CMOS

Complementary Metal-Oxide Semiconductor (CMOS) provides high speeds and consumes little power which is why some RAM chips and flash memory chips utilize it. CMOS uses battery power to retain information even when the power is off. Battery-backed CMOS memory chips can keep the calendar, date and time current even when the computer is off. Flash memory often uses CMOS technology to store a computer's start-up information.

DIMMs

DIMMs (Dual In-line Memory Module) is when the pins are on opposite sides of the circuit board and do not connect thus forming two sets of contacts.

Control unit

Directs and coordinates most of the operations in the computer. Directs the arithmetic logic unit, registers and buses.

Clock cycle

Each tick equates to a clock cycle. Processors are typically super-scalar which means they can execute more than one instruction per clock cycle.

Chip

Integrated circuit can contain millions of elements: resistors,capacitors & transistors.

Adapter card types

Known as an expansion card or adapter board; is a circuit board that enhances the functions of a component providing connections to peripheral devices. An expansion slot is a socket on a desktop or server motherboard that can hold an adapter card. Two popular adapter cards are sound and video cards. Type then Purpose Bluetooth-Enables Bluetooth connectivity MIDI-Connects to musical instruments Modem-Connects to transmission media, such as cable television lines 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-Provides enhanced graphics capabilities, such as accelerated processing or the ability to connect a second monitor Video Capture-Connects to a video camera

USB

Mobile computers typically do not have expansion slots due to their smaller size, but users can purchase a USB adapter. The USB adapter is a dongle that plugs into a USB port, enhances functions of a mobile computer, providing connections to peripheral devices. USB adapters can be used to add memory, communications, multimedia, security or storage. The most common USB adapter is the USB flash drive that provides additional storage. Hot plugging allows you to insert and remove a flash memory device while the computer is running versus opening up the system to install a card on the motherboard.

Flash memory

Nonvolatile memory that can be erased electronically and rewritten. Computers use flash memory to hold their start-up instructions as it allows the computer to update contents easily like changing from daylight savings time to standard time. Flash memory chips store data and programs on mobile devices and peripheral devices like smartphones and printers. Memory cards contain flash memory instead of on a chip for removable devices.

Plug and Play

Plug and Play Technology refers to the computer's ability to automatically recognize peripheral devices as you install them. This means that you can begin using a device as soon as you plug it in. This technology permits computers to connect and communicate with devices easily but also creates security flaws that allow hackers to take control of things such as: security systems, routers, Smart TVs, printers, webcams and any other device connected to the Internet. "40-50 million devices are susceptible to remote attacks." ~ Rapid7, security firm

ROM

ROM (Read Only Memory) refers to memory chips storing permanent data and instructions. Read only means that the chip cannot be modified, is nonvolatile meaning their contents are not lost when power is removed from the computer. ROM is included in peripheral devices like printers that may contain data for fonts on the ROM chips. Rom chips called firmware contain permanently written data, instructions and information such as a computer's start up instructions.

RAM

Random Access Memory, also called main memory, consists of memory chips that can be read from and written to. RAM can accommodate multiple programs and applications simultaneously. Saving is copying from RAM to a storage device. Dynamic RAM (DRAM) must be reenergized constantly or it will lose its contents. Static RAM (SRAM) are faster and more reliable and do not have to be reenergized and are much more expensive.

Types of buses

Recall that a computer processes and stores data as a series of electronic bits which transfer internally within the circuitry of the computer along electrical channels. Each one of these electrical channels is called a bus which allows devices inside and outside of the system to communicate with each other, similar to vehicles traveling on a highway. Buses transfer bits from input devices to and from the memory, processor to output or storage devices. Buses consist of data and addresses. The data bus transfers the data. The address bus transfers the information and tells the data where it should reside in the memory.System bus also called the front side bus (FSB) is part of the motherboard connecting the processor to the main memory. The backside bus (BSB) connects the processor to the cache. The expansion bus allows the processor to communicate with peripheral devices. When the term bus is used by itself, it is usually referring to the system bus, front side bus (FSB).

Power supply (AC/DC)

The power supply or laptop adapter converts the wall outlet AC (Alternating Current) power into DC (Direct Current) power because the standard wall outlet supplies and unsuitable power. A fan is build into the power supply to keep the power supply cool. Different motherboards and devices require different wattages on the power supply. The computer will not function properly if the power supply is not providing necessary power. AC adapters are used for some external peripheral devices such as: cable modem, speakers, printer. One end of the adapter plugs into the wall outlet while the other attaches to the peripheral. The AC adapter converts the AC power into the DC power that the peripheral requires.

Fetching

The process of obtaining a program or an application instruction or data item from memory.

Machine cycle

The processor repeats a set of four basic operations for every instruction: fetching, decoding,executing, and storing if necessary.

L1,L2,L3 Cache

There are two common types of cache: Memory cache stores frequently used instructions and data. Level 1 (L1) cache is built directly on the processor chip and has very small capacity Level 2 (L2) is slower than L1 but has much larger capacity. A type of L2 cache is the ATC (Advanced transfer cache) built directly on the processor chip. Level 3 (L3) cache is separate from the processor chip on the motherboard and exists only on computers that use L2 ATC. A processor searches memory in this order: L1, L2, L3 (if exists), RAM.

Multi-core processor

a single chip with two or more separate processor cores. Used in all sizes of computers.

Heat sink

a small ceramic or metal component with fans on its surface that absorbs and disperses heat produced by electrical components.

Expansion slot

a socket on a desktop or server motherboard that can hold an adapter card.

Transistor

acts as an electronic switch that opens or closes the circuit for electrical charges.

Memory

consists of electronic components that store instructions waiting to be executed by the processor, data needed by by those instructions and the results of processing the data.Also consists of one or more chips on the motherboard or other circuit board. stores three basic items: The OS and other programs that control or maintain the computer Applications that carry out a specific task, such as word processing The data being processed by the applications and the resulting information

Firmware

contain permanently written data, instructions and information such as a computer's start up instructions.

Graphics card

converts computer output into a video signal traveling through a cable to the monitor to be displayed on the screen. Functionality is built into the adapter card but some have cables that connect to the card then to the device such as a digital video camera.

Bus width

determines the amount of bits that the computer can transmit at one time.

Processor

directs and coordinates most of the operations in the computer. interprets and carries out basic instructions that operates a computer.

Non-volatile memory

does not lose its content when power is removed. It is permanent memory: ROM, flash memory, CMOS.

Sound card

enhances the sound-generating capabilities of a personal computer; allowing sound to be input through a microphone and output through speakers or headphones.

Static Ram

faster and more reliable and do not have to be re energized and are much more expensive.

Storing

in this context of machine cycle, storing is writing the result to memory (not to a storage medium).

The control unit

interprets and executes instructions in memory.

Bytes

known as a character, is the basic storage unit in memory.Instructions and data exist as bytes; each byte temporarily resides in a location in memory that has an address. An address is a unique number that identifies the location of a byte in memory. To access data or instructions, the computer reference the addresses that contain bytes of data.

Volatile memory

loses its contents when power is removed. Memory is temporary, RAM.

Decoding

refers to the process of translating the instruction into signals the computer can execute.

Bits

smallest unit of information that a computer can hold; stands for binary digit

Data bus

transfers data

Address Bus

transfers the information and tells the data where it should reside in the memory.

Dynamic Ram

transfers the information and tells the data where it should reside in the memory.

Liquid cooling technology

uses continuous flow of fluids like water or glycol to reduce the temperature of the processor by transferring the heated fluid away from the processor to a radiator-type grill which then cools the liquid and returns it cooled to the processor.