Hardware and software

Read Only Memory (ROM)

A chip helps the processor transfer information between the keyboard, screen, printer and other peripheral devices. These instructions are called the ROM BIOS (basic input/output system).

Address Bus

A collection of wires connecting the CPU with main memory that is used to identify particular locations (addresses) in main memory.

RAID 10

A combination of RAID 1 and 0

Standalone

A complete operating system that works on desktop computers

Arithmetic Logic Unit (ALU)

A component of the processor that performs arithmetic, comparison, and other operations. Arithmetic operations include basic calculations such as addition, subtraction, multiplication, and division.

Manage Devices

A driver tells the operating system how to communicate with a specific device. Every device connected to a computer has its own set of commands and thus requires its own specific driver. Plug and Play devices do not need manual driver installation as they run off a set of preinstalled specifications.

File System

A file system will manage and display all files that a user creates. They typically can search, copy, rename and delete files from the hard drive.

SSD

A flash memory storage device with its own processor to manage its storage

RAID

A hard disk configuration that connects multiple smaller hard drives to act as single larger hard drive.

Server

A multiuser OS that coordinates and organises how multiple users access and share resources on a network.

Registers

A processor contains small, high-speed storage locations, which temporarily hold data and instructions. They are part of the processor, not part of memory or a permanent storage device.

Program Counter

A register in a computer processor that contains the address (location) of the instruction being executed at the current time.

Personal Virtualisation

A single computer simultaneously runs multiple virtual PCs, each with its own suite of applications. Users can run different applications without needing to restart or switch machines.

System Clock

A small quartz crystal that controls the timing of all computer operations.

Expansion slot

A socket for adaptor cards to plug into

Standard Operating Environment (SOE)

A standard implementation of an operating system and its associated software. It can apply to servers, desktops, laptops, thin clients, and mobile devices.

Virtual Machine

A tightly isolated software container that runs its own operating system and applications as if it were a physical computer. It behaves exactly like a real computer and has virtual (software allocated portion of) CPU, RAM, Hard disk space and NIC. The OS, applications and Virtual Computer cannot tell that it isn't real, nor can other computers on the same network

ATC (Advance Transfer Cache)

A type of cache built on the directly on the processor chip.

Continuous Data Protection

All data is backed up when data is changed.

Standalone

Also called Client OS as they work in conjunction with a server

Embedded

Also called Mobile

Adaptor Cards

Also called expansion cards

Read Only Memory (ROM)

Also known as firmware. One of these chips inside a PC tells the processor what to do when you first turn on the computer. These instructions are called the ROM bootstrap. To get the computer going, it performs a "power-on self-test" or POST.

Operating System - Definition

An Operating System is software that communicates with the computer on the most basic level. It manages the hardware and software.

Virtual Memory

An imaginary memory area that acts as an alternate set of memory addresses. When the program is executed the virtual memory addresses are converted into real memory addresses.

Distributed Processing

Any computing that involves multiple computers remote from each other that each have a role in a computation problem or information processing.

Online Storage

Backup data is stored off site so no data is lost even if backup drives are destroyed too.

L1 Cache

Cache built directly on the processor chip. It has the smallest capacity but greatest speed.

CISC

Can do complex operations, operations that would usually take multiple operations, in a single step.

RISC

Can only execute on instruction at a time.

CISC

Chips are expensive to produce and use a lot of power.

Adaptor Cards

Circuit boards that enhance the functions of a desktop or server system.

CMOS

Complementary Metal Oxide Semiconductor, Highs speeds at low power. Battery Powered so continues to be powered when the computer is off

CISC

Complex instruction set computer. Supports many complex instructions.

RAM

Computer memory that can be accessed randomly; that is, any byte of memory can be accessed without touching the preceding bytes. It is where the data and instructions are stored.

Manage Concurrency

Concurrency is the ability of an operating system to multitask. A multitasking operating system allows two or more programs to reside in memory at the same time.

Parts of the CPU

Control Unit, ALU, Registers, System Clock

Full Backup

Copies across all of the files

Paging/ Swapping

Copying virtual pages from disk to memory.

Advantages of Cloud Computing

Cost benefits, Storage, Disaster Management, Mobility, Security, Benefits from a larger company being specialised in storage and will have better physical security of the servers., Collaboration

Benefits of VM

Cost saving due to fewer physical machines and maintenance of these, Energy savings, overcoming hardware issues.

Server

Desktop operating systems act as clients to this server

Differential Backup

Fast backup that requires less space

Selective Backup

Fast backup with the most flexibility

Incremental Backup

Fast backup, requires less space, only most recent changes saved.

Full Backup

Fastest Recovery

Snapshot

Fastest, almost instant backup time.

Fetch Execute Cycle

Fetch, Decode, Execute, Store

System Clock

Generates regular electronic pulses, or ticks, that set the operating pace of components of the system unit. Each tick equates to a clock cycle.

Embedded

Has the same role as a desktop OS

Sequential Processing

Instructions are processed in the order they are received.

L3 Cache

Is cache on the motherboard that is separate from the processor chip. It exists only on computers that use L2 ATC.

SSD

Is faster, quieter, more durable and less power consuming than HDDs

L2 Cache

Is slightly slower than L1 but has a much larger capacity. Modern Processes use ATC. Processors with ATC perform much faster than those without.

Parallel Processing

Is the simultaneous use of more than one CPU or processor core to execute a program.

Read Only Memory (ROM)

It cannot be written to or erased by the user.

Control Unit

It fetches the code for the instructions in the fetch-execute cycle and directs and operates the parts of the CPU.

Cache

It helps to speed up the processes of the computer because it stores frequently used data and instructions.

Flash Memory

It is a type of non-volatile memory that can be erased electronically and rewritten

Control Unit

It is the component of the processor that directs and coordinates most of the operations in the computer. It interprets each instruction issued by a program or an application and then initiates the appropriate action to carry out the instruction. Types of internal components that the it directs include the arithmetic logic unit, registers, and buses.

Standard Operating Environment (SOE)

It is typically implemented as a standard disk image that can be mass deployed to more than one computer in an organisation. It can include the base operating system, a custom configuration, standard applications used within an organisation, software updates and service packs.

Server Virtualisation

It is where multiple logical servers are hosted on the one physical computer. Each server has its own OS

Arithmetic Logic Unit (ALU)

It performs comparison operations involving comparing one data item with another to determine whether the first item is greater than, equal to, or less than the other item. Depending on the result of the comparison, different actions may occur.

Data Bus

It transfers the data from one component on the motherboard or from one computer to another. This includes transferring data to and from RAM and the CPU

Motherboard

It typically contains the CPU, BIOS, memory, mass storage interfaces, serial and parallel ports, expansion slots, and all the controllers required to control standard peripheral devices, such as the display screen, keyboard, and disk drive. Collectively, all these chips are known as the chipset.

Multicore Processing

It uses multiple separate cores.

Cloud Computing

It uses multiple severs over a network to perform tasks such as storing files, managing data and processing information.

Selective Backup

Least manageable.

Operating System - Five Functions

Manage Memory, Manage Concurrency, Manage Devices, Scheduling, File System

MPP

Massively parallel processing.

RAID 1

Mirroring

RAID

More expensive that regular hard drives but is more reliable due to data redundancy

Flash Memory

Most computers use it to hold their start-up instructions so it can be easily changed (for example daylight saving time)

Incremental Backup

Only copies files that have changed since the last backup.

Differential Backup

Only copies files that have changed since the last full backup

Superscalar

Processors that can execute more than one instruction per clock cycle.

Virtual Memory

Programs use these virtual addresses when there is insufficient RAM.

RAID 0

Provides no data redundancy. It is normally used to increase performance, although it can also be used as a way to create a large logical disk out of two or more physical ones.

UPS

Provides short-term power to servers in the event of a power surge of power outage

Continuous Data Protection

Real-time backups, very fast recovery.

Differential Backup

Recovery is time consuming because the last full backup plus all the backups since are needed.

Incremental Backup

Recovery is time consuming because the last full backup plus all the incremental backups are needed.

RISC

Reduced instruction set computer.

Standard Operating Environment (SOE)

Reduces support costs and training costs by providing a familiar environment.

RAID

Redundant Array of Independent Disks

Snapshot

Requires external hardware.

Sequential Processing

Running a single task to completion on a single processor, in contrast to parallel processing or multitasking.

Disadvantages of Cloud Computing

Security Risks as it can be hacked more easily as everything is on the internet, Loss of control of servers, Compatibility, Contracts, Fast and Reliable internet connectivity is required

Full backup

Slowest Backup Time

Registers

Small areas of data storage used by the control unit in the fetch-execute cycle.

RAID 0

Splits data evenly across two or more disks (striped) without parity information for speed.

RAID 0

Striping

RISC

Supports fewer instructions than CISC.

CPU

The Central Processing Unit (CPU) interprets and carries out the basic instructions that operate a computer. The processor significantly impacts overall computing power and manages most of a computer's operations.

Desktop Virtualisation

The centralisation of applications at a data centre. This makes systems easier to access as each virtual machine is hosted on a server. It works well for workers who move between machines or work remotely. Users can remote access the computers to use them

Bus

The communications link between components

Thrashing

The computer spends much of its time paging instead of executing.

Motherboard

The motherboard is the central circuit board of the computer.

Scheduling

The operating system determines the order in which tasks occur. Tasks include receiving data from an input device, processing instructions, sending information to an output device and transferring items to and from memory. Sometimes a device will be busy when a request for another task occurs, so the operating system must store the instruction. While waiting for devices to become idle, the operating system puts the items in a buffer.

Virtual Memory

The operating system divides it into pages, which contain a fixed number of addresses. Each page is stored on a disk until it is needed and is copied into RAM.

Control Bus

The physical connections that carry control information between the CPU and other devices within the computer. It carries the signals that report the status of various devices.

Executing

The process of carrying out the commands.

Fetching

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

Decoding

The process of translating the instruction into signals the computer can execute.

Manage Memory

The purpose of memory management is to optimise the use of the computer's internal memory (RAM). The RAM holds data and instructions while the processor executes them. Then it carefully monitors the memory containing them before releasing them when they are no longer needed.

Mapping

Translating virtual memory addresses into real addresses.

UPS

Uninterruptable Power Supply

Selective Backup

Users choose which files and folders to backup

Snapshot

Uses external hardware to instantly create a read-only backup of the current system.

MPP

Using more than one processor to execute instructions at the same time.

Continuous Data Protection

Very expensive and requires the most space.

Hence, you can have a Linux Server on the same hardware as a windows 2008 server. Saves purchase of new equipment and allows easier managing of servers

Virtualisation

Pipelining/ Hyperthreading

When the processor fetches a second instruction before the first is complete

Standalone

Windows, Linux, etc.

RAID 10

Works by striping and mirroring your data across at least two disks.

RAID 1

Writes data to both disks simultaneously at the same time to duplicate data. If one disk fails or needs to be replaced, the other disk has all the necessary data elsewhere.

Storing

Writing the result to memory (RAM, not to a storage medium).

HDD

a storage device that contains one or more inflexible, circular platters that use magnetic particles to store data. Depending on how the particles are aligned, they represent either a zero or a one

Sound card

allows sound to be input through microphones and output through headphones or external speakers

A video card (graphics card)

converts the computer outputs into a signal that travels through a cable to the monitor.