Quick Tip: Speed Up Page Caching

Page Cache or ‘disk cache’ is a buffer of disk-backed pages kept in RAM by the operating system for quicker access. See here for reference.

Disk cache is crucial in Windows XP. However, the default I/O pagefile setting of Windows XP limits the performance of your computer. By applying the following tweak, you will see a significant increase of speed of your sluggish XP.

  • Open the Windows Registry.
  • Navigate to [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\IoPageLockLimit
  • Modify the value in Hex depending on the size of your RAM

RAM : modified value (Hex)
64 MB : 1000
128 MB : 4000
256 MB : 10000
512 MB or more : 40000

Don’t forget to reboot your machine after applying this tweak. If you face any problems (which is unlikely), then you should revert to your previous settings.

Desktop computing with Linux: Prelude #3

Any GNU/Linux newbie will be baffled by the concept of a ‘desktop environment’ because it is not what he/she is used to. Give them the familiar interface of Windows XP or Windows 7 and they will be happy lest they should exclaim “What is this thing”? Let us be open minded and adaptive as much as we can and dive into the concept of desktop environment.

The graphical user interfaces (GUI) that you interact with every time you use a computer or a laptop is the result of evolution of users’ need to interact with electronic devices with images rather than text commands.

The first solution to it was the Xerox Alto, an early personal computer developed at Xerox PARC in 1973. It was the first computer to use the desktop metaphor and mouse-driven graphical user interface (GUI). Alternately, it was the outcome of a concept called ‘WIMP‘ that was also developed at Xerox PARC and which is the basis of all GUIs that are implemented on most popular operating systems including Windows, Mac OSes and obviously GNU/Linux.

The Xerox Alto was the first to use a graphical user interface.

The file manager program running on the Alto.

Wait how does it relate to desktop environment?

In graphical computing, a desktop environment (DE) commonly refers to a style of graphical user interface (GUI) derived from the desktop metaphor that is seen on most modern personal computers. A desktop environment typically consists of icons, windows, toolbars, folders, wallpapers and desktop widgets. These GUIs help the user in easily accessing, configuring, and modifying many important and frequently accessed specific operating system (OS) features.

In short, it is just a style of graphical user interfaces following the desktop metaphor. A few examples can help understand what it exactly is.

The most common desktop environment on personal computers is Microsoft Windows’ built-in interface. It is titled Luna in Windows XP and Aero in Windows Vista and Windows 7. Also common is Aqua, included with Apple’s Mac OS X.

Luna

Aero

Aqua

Mainstream desktop environments for Unix-like operating systems using the X Window System include Unity, KDE, GNOME, Xfce, and LXDE.

Note: Some may refer to Unity and Gnome Shell as shells but that is not important to a Linux newbie. So let’s consider them as Desktop Environments.

Unity

KDE

GNOME

The main advantage of desktop environment on GNU/Linux systems is that they can be swapped for another desktop environment that you like, unlike on Windows and Mac OS X where you are trapped with the default one. A GNU/Linux system can have multiple desktop environments and they can be changed before you log in to the operating system.

So that’s all.

What is the Difference Between Wi-Fi and Bluetooth

Most of us are well aware of the fact, that wi-fi and bluetooth are both wireless standards and use waves at radio frequency for transmission purposes. This is the reason why many of us are confused between the two technologies, and think that they solve the same purpose. There is however, a lot of difference between wi-fi and bluetooth. Here, in this article, I will try to explain these differences to you. Both the wi-fi (wireless fidelity) and the bluetooth standards are based on separate protocols. This gives rise to the differences between wi-fi and bluetooth, which causes their fields of application to change drastically. Let’s try to understand the difference between wi-fi and bluetooth technology, comparing and contrasting them, on the various aspects of their working.

What is Bluetooth? Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances from fixed and mobile devices, creating personal area networks (PANs) with high levels of security. Created by telecoms vendor Ericsson in 1994.A number of devices that you may already use take advantage of this same radio-frequency band. Baby monitors, garage-door openers and the newest generation of cordless phones all make use of frequencies in the ISM band. Making sure that Bluetooth and these other devices don’t interfere with one another has been a crucial part of the design process.                                    A typical Bluetooth mobile phone headset.

  • Bluetooth networking transmits data via low-power radio waves. It communicates on a frequency of 2.45 gigahertz (actually between 2.402 GHz and 2.480 GHz, to be exact). This frequency band has been set aside by international agreement for the use of industrial, scientific and medical devices (ISM).
  • One of the ways Bluetooth devices avoid interfering with other systems is by sending out very weak signals of about 1 milliwatt. By comparison, the most powerful cell phones can transmit a signal of 3 watts. The low power limits the range of a Bluetooth device to about 10 meters (32 feet), cutting the chances of interference between your computer system and your portable telephone or television. Even with the low power, Bluetooth doesn’t require line of sight between communicating devices. The walls in your house won’t stop a Bluetooth signal, making the standard useful for controlling several devices in different rooms. Using bluetooth, you can transfer data at the rate of 800 kbps.
  • Bluetooth can connect up to eight devices simultaneously. With all of those devices in the same 10-meter (32-foot) radius, you might think they’d interfere with one another, but it’s unlikely. Bluetooth uses a technique called spread-spectrum frequency hopping that makes it rare for more than one device to be transmitting on the same frequency at the same time. In this technique, a device will use 79 individual, randomly chosen frequencies within a designated range, changing from one to another on a regular basis. In the case of Bluetooth, the transmitters change frequencies 1,600 times every second, meaning that more devices can make full use of a limited slice of the radio spectrum. Since every Bluetooth transmitter uses spread-spectrum transmitting automatically, it’s unlikely that two transmitters will be on the same frequency at the same time. This same technique minimizes the risk that portable phones or baby monitors will disrupt Bluetooth devices, since any interference on a particular frequency will last only a tiny fraction of a second.
  • Bluetooth systems create a personal-area network (PAN), or piconet, that may fill a room or may encompass no more distance than that between the cell phone on a belt-clip and the headset on your head. Bluetooth is used for data and file transfers, from one device to the other. You can access a bluetooth enabled printer from your computer, using it.

What Is WiFi?

Wifi is a standard for wirelessly connecting electronic devices. A Wi-Fi device, such as a personal computer, video game console, smartphone, or digital audio player can connect to the Internet via a wireless network access point ,by creating Local Area Network (LANs). An  access point (or hotspot) has a range of about 20 meters (65 feet) indoors and a greater range outdoors. Multiple overlapping access points can cover large areas. “Wi-Fi” is a trademark of the Wi-Fi Alliance and the brand name for products using the IEEE 802.11 family of standards.                                                     A roof-mounted Wi-Fi antenna

  • They transmit at frequencies of 2.4 GHz or 5 GHz. This frequency is considerably higher than the frequencies used for cell phones, walkie-talkies and televisions. The higher frequency allows the signal to carry more data. where as, wi-fi is susceptible to data losses and hence has lower speeds. If you are connected to the Internet using wi-fi, your downloading speed will be less than what you would get when you are connected using broadband internet.
  • A computer’s wireless adapter translates data into a radio signal and transmits it using an antenna.A wireless router receives the signal and decodes it. The router sends the information to the Internet using a physical, wired Ethernet connection.The process also works in reverse, with the router receiving information from the Internet, translating it into a radio signal and sending it to the computer’s wireless adapter. The radios used for WiFi communication are very similar to the radios used for walkies-talkies, cell phones and other devices. They can transmit and receive radio waves, and they can convert 1s and 0s into radio waves and convert the radio waves back into 1s and 0s.
  • WiFi radios can transmit on any of three frequency bands. Or, they can “frequency hop” rapidly between the different bands. Frequency hopping helps reduce interference and lets multiple devices use the same wireless connection simultaneously.
  • As long as they all have wireless adapters, several devices can use one router to connect to the Internet. This connection is convenient, virtually invisible and fairly reliable; however, if the router fails or if too many people try to use high-bandwidth applications at the same time, users can experience interference or lose their connections.

Difference between Internet and World Wide Web?

The Internet and the World Wide Web have a whole-to-part relationship. The Internet is the large container, and the Web is a part within the container. It is common in daily conversation to abbreviate them as the “Net” and the “Web”, and then swap the words interchangeably. But to be technically precise, the Net is the restaurant, and the Web is the most popular dish on the menu.

What is The Internet?
The Internet is a Big Collection of Computers and Cables.

The Internet is named for “interconnection of computer networks”(or network of networks). It is a massive hardware combination of millions of personal, business, and governmental computers, all connected like roads and highways , forming a network in which any computer can communicate with any other computer as long as they are both connected to the Internet. Information that travels over the Internet does so via a variety of languages known as protocols.

The Internet started in the 1960’s under the original name “ARPAnet”. ARPAnet was originally an experiment in how the US military could maintain communications in case of a possible nuclear strike. With time, ARPAnet became a civilian experiment, connecting university mainframe computers for academic purposes. As personal computers became more mainstream in the 1980’s and 1990’s, the Internet grew exponentially as more users plugged their computers into the massive network. Today, the Internet has grown into a public spiderweb of millions of personal, government, and commercial computers, all connected by cables and by wireless signals.

No single person owns the Internet. No single government has authority over its operations. Some technical rules and hardware/software standards enforce how people plug into the Internet, but for the most part, the Internet is a free and open broadcast medium of hardware networking.

What is The Web (World Wide Web)?
The Web Is a Big Collection of HTML Pages on the Internet.

The World Wide Web, or simply Web, is a way of accessing information over the medium of the Internet. It is a subset of the Internet dedicated to broadcasting HTML pages. It is an information-sharing model that is built on top of the Internet. The Web uses the HTTP protocol(hypertext transfer protocol), only one of the languages spoken over the Internet, to transmit data. Web services, which use HTTP to you and me to “jump” (hyperlink) to any other public web page. Use the the Web to share information. The Web also utilizes browsers, such as Internet Explorer or Firefox, to access Web documents called Web pages that are linked to each other via hyperlinks. Web documents also contain graphics, sounds, text and video.

In 1980,  Tim Berners-Lee, an independent contractor at the European Organization for Nuclear Research (CERN), Switzerland, built ENQUIRE, as a personal database of people and software models. By 1990, Berners-Lee had built all the tools necessary for a working Web: the HyperText Transfer Protocol (HTTP) 0.9, the HyperText Markup Language (HTML), the first Web browser (named WorldWideWeb, which was also a Web editor), the first HTTP server software (later known as CERN httpd), the first web server (http://info.cern.ch), and the first Web pages that described the project itself. The browser could access Usenet newsgroups and FTP files as well. However, it could run only on the NeXT; Nicola Pellow therefore created a simple text browser that could run on almost any computer called the Line Mode Browser.To encourage use within CERN, Bernd Pollermann put the CERN telephone directory on the web — previously users had to log onto the mainframe in order to look up phone numbers. On August 6, 1991, Berners-Lee posted a short summary of the World Wide Web project on the alt.hypertext newsgroup. This date also marked the debut of the Web as a publicly available service on the Internet.

The Web is just one of the ways that information can be disseminated over the Internet. The Internet, not the Web, is also used for e-mail, which relies on SMTP, Usenet news groups, instant messaging and FTP. So the Web is just a portion of the Internet, albeit a large portion, but the two terms are not synonymous and should not be confused.

Desktop computing with Linux: Prelude #2

Well, now that you’re onto using a Linux system on your desktop PCs, you must get familiar with some concepts. The two main concepts that you need to know: Distribution and Desktop Environment. Today we’ll discuss about a Distribution or more precisely a Linux Distribution.

Wikipedia defines it as following:

“A Linux distribution is a member of the family of Unix-like operating systems built on top of the Linux kernel. Such distributions (often called ‘distros’ for short) are Operating systems including a large collection of software applications such as word processors, spreadsheets, media players, and database applications. The operating system will consist of the Linux kernel and, usually, a set of libraries and utilities from the GNU Project, with graphics support from the X Window System.”

There are many distros that are desktop oriented and are focused to work “out-of-the-box” right away after the installation. But any new user migrating to Linux-based system would be better off with a commercially-backed distribution because of the quality of the build of the Operating System which is excellent and because the support is easily available either on respective forums and IRC channels for support or on the Internet. Notable commercially-backed distributions include Ubuntu (Canonical Ltd.), Fedora (Red Hat), openSUSE (Novell) and Mandriva Linux (Mandriva).

Ubuntu 11.04

Fedora 15

openSUSE 11.4

Mandriva 2011

One of the most notable features of these distros is the live mode in which the distro can be copied onto a CD, DVD or a USB via third party tools to make Live CD, Live DVD or Live USB respectively which can be booted to test the operating system before installing it.

Another thing that you may need to know is about ‘packages.’ Distributions are normally segmented into packages. Packages are very different from ‘installers’ as in Windows systems. The installers bundle all the dependent libraries and the main application in a single executable file whereas each package contains independent application, service or library. Examples of packages are a library for handling the PNG image format, a collection of fonts or a web browser. These packages can be installed from a repository via software management applications/commands that manage them.

These distros also include installation program that help users to partition the hard drive and install the operating system. Believe it or not the installation procedure has become too easy for anyone to install the system.

Ubuntu Installation Procedures

Lastly, the joys of using your favorite applications aren’t taken away from you as browsers like Mozilla Firefox, Google Chrome and Opera, media player like VLC or softwares like Adobe Reader, Adobe Flash Player, Skype etc. are available for these Linux distros.