Tag Archives: Computers

What happens when you turn a computer on?

Working on a computer is so easy nowadays that we find even children handling them expertly. However, several things start to happen when we turn on the power to a computer, before it can present the nice user-friendly graphical user interface (GUI) screen that we call the desktop. In a UNIX-like operating system, the computer goes through a process of booting, BIOS, Master Boot Record, Bootstrap Loading, grub, init, before reaching the operating level.


As soon as you switch on the computer, the motherboard initializes its own firmware to get the CPU running. Some registers, such as the Instruction Pointer of the CPU, have permanent values that point to a fixed memory location in a read only memory (ROM) containing the basic input output system (BIOS) program. The CPU begins executing the BIOS from the ROM.


The BIOS program has several important functions, which begin with the power on self-test (POST) to ensure all the components present in the system are functioning properly. POST indicates any malfunction in the form of audible beeps. You have to refer to the Beep Codes of the motherboard to decipher them. If the computer passes the test for the video card, it displays the manufacturer’s logo on its screen.

After checking, BIOS initializes the various hardware devices. This allows them to operate without conflicts. Most BIOSs follow the ACPI create tables for initializing the devices in the computer.

In the next stage, the BIOS looks for an Operating System to load. The search sequence follows an order predefined by the manufacturer in the BIOS settings. However, the user can change this Boot Order to alter the actual search. In general, the search order starts with the hard disk, CD-ROMs, and thumb drives. If the BIOS does not find a suitable operating system, it displays an error. Otherwise, it reads the master boot record (MBR) to know where the operating system is located.

Master Boot Record

In most cases, the operating system resides in the hard disk. The first sector of the hard disk is the master boot record (MBR), and its structure is independent of the operating system. It consists of a special program, the bootstrap loader, and a partition table. The partition table is actually a list of all the partitions in the hard disk and their file system types. The bootstrap loader contains the code to start loading the operating system. Complex operating systems such as Linux use the grand unified boot loader (GRUB), which allows selecting of one of the several operating systems present on the hard disk. Booting an operating system using GRUB is a two-stage process.


Stage one of the GRUB is a tiny program and its only task is to call stage two, which contains the main code for loading the Linux Kernel and the file system into the RAM. The Kernel is the core component of the operating system, remains in the RAM throughout the session, and controls all aspects of the system through its drivers and modules. The last step of the kernel boot sequence is the init, which determines the initial run-level of the system. Unless otherwise instructed, it brings the computer to the graphical user interface (GUI) for the user to interact.

Raspberry Pi to Displace the Business PC

For a business establishment, maintaining PCs for each of their several hundred employees can be an expensive proposition. It is much simpler and cheaper to have a centralized workstation with several thin clients connecting to it. The ubiquitous single board computer, the Raspberry Pi (RBPi) is a suitable component for use as such a thin client.

As the low cost of the Raspberry Pi makes it a very attractive proposition for use as a thin client computer, Citrix is offering an HDX Ready Pi to replace the regular desktop PC. They are coupling the RBPi with virtual desktops such as the Citrix XenDesktop and the XenApp virtual apps. The combination is an ideal replacement for the traditional desktop PC and its IT refresh cycle.

At the heart of the project are two thin client operating systems, ThinLinX and TLXOS, based on Raspbian, the default OS for the Raspberry Pi. These provide the image for the RBPi and include the client and management software. Citrix is making use of these to instill an HDX SoC Receiver SDK within the securely locked-down Linux OS and the SDK provides full device management for updating firmware, remote configuration, and DHCP, making the RBPi a completely plug-n-play device.

Available fully assembled and ready-to-order from Citrix partners ViewSonic and Micro Center, the HDX Ready Pi thin-clients come preloaded with all the necessary software, power supply, flash storage, VESA mount option, all packaged in a production case. Any IT administrator can deploy these thin-clients in a matter of seconds.

Apart from being just a cheap PC alternative, these RBPI thin-clients offer businesses several new business paradigms. For instance, businesses now need not pay a premium for security and management of all their PCs, and they can expand their number of users to cover the entire organization.

The Citrix HDX Ready Pi is easy to set up. As it is small, distribution is simplified and employees can connect it up to an available display and be productive in a matter of minutes. IT can configure the management software, recognize the HDX Ready Pi in the network, take control of it, and point it automatically to the correct Citrix Storefront server. The user can then run any instant virtual app with desktop access.

As the RBPi thin-clients have no hard disks to fail, there is also no data and time wasted in diagnosing device problems. This eliminates all desk-side support, as any issue can be solved simply by swapping the device.

The low cost of thin-clients also eliminates treating them as trackable financial assets. Businesses can rather consider the Citrix HDX Ready Pi as non-capitalized office expenses, providing a compelling situation to virtualize remote branch offices all over the world.

As there is no provision to store or cache corporate data, businesses can safely distribute the HDX Ready Pi among employees for occasionally working from home over Wi-Fi or for teleworking. Employees can take the device home and use it safely for remote access.

Although the Citrix HDX Ready Pi has a Kensington lock slot, its low cost makes physical security almost a non-issue. Moreover, as the device is purpose-built for Citrix, it can be safely used as a pervasive computing device in an office campus or in public spaces.

The Emergence of BBB: the BeagleBone Black

Many a time we have wished our bulky PCs that occupy so much of the desktop space could somehow be magically squeezed into a portable unit. Although such systems are there including the new smartphones and tablets, their sky-high prices are very discouraging for most of us.

Despair not, for such a package has arrived and is well within the reach of an average person’s pocket. Moreover, if you are technically oriented, you could build one yourself. Texas Instruments has provided the core processor and BeagleBoard has provided the packaging. The result is the low-cost, low power, fan-less, single-board computer called the BeagleBone, a latest addition to the BeagleBoard family.

The low-cost, fan-less, low power, single-board computers from BeagleBoard utilize the Texas Instruments’ OMAP3530 application processor. This offers laptop like performance and facility for expansion, without the bulk, the noise and the expense that are typical of desktop machines. Within the OMAP3530, there is a 600MHz ARM Cortex-A8 Micro Controller Unit (MCU), which predicts branches with high accuracy and a 256KB L2 cache memory.

The on-board USB 2.0 OTG port serves a dual purpose; you can transfer data out from the board or allow the board to read data in from an external source. Although the board has a separate 5V DC power socket, power to the board can be supplied through the USB port as well. The board also has a mini-A connector, to which you can connect standard PC peripherals using a standard-A to mini-A cable adapter. A DVI-D connector allows a HDMI display to be connected using a HDMI to DVI-D adapter. The third connector is the MMC/SD/SDIO card connector. To give you the best graphics experience, the BeageBoard has a state of the art POWERVR graphics hardware, which will render 10 million polygons each second.

For people who were not satisfied with the power of the BeagleBoard single-board computer, BeagleBoard has added the BeagleBone Black or BBB. This is the newest addition to the BeagleBoard family, and continues the saga of the low-cost, low power, single-board computers. To provide the additional features, an advanced MCU, the Texas Instruments’ Sitara AM3359 has been used. This is an ARM Cortex-A8 32-bit RISC processor, featuring a speed of 1GHz, and gives BBB the power along with a 512-MB DDR3L 400MHz SDRAM and 2GB 8-bit eMMC on-board flash memory. This frees up the micro SD card slot for further expansions.

The 92-pin headers are Cape compatible, meaning the existing family of cape plug-in boards can be used as well. The on-board HDMI allows direct connection to monitors and TVs. External electronics circuitry can be controlled by the UART0 serial port. For connecting to the Internet, a 10/100 RJ45 Ethernet connector has been provided.

You will need the latest Angstrom distribution eMMC flasher to load the latest Linux distribution. This is a 4GB image, that has to be uncompressed using unxz and written to a micro SD card. Connect an HDMI monitor, and after plugging in the micro SD card in the slot of the BBB, you can power on your single-board Linux computer. Take care to hold the boot button on while powering, and watch the LEDs on the BBB flash and then stay on.

The Future of Cloud Computing

What is Cloud Computing?

Cloud Computing, an efficient method to balance between dealing with voluminous data and keeping costs competitive, is designed to deliver IT services consumable on demand, is scalable as per user need and uses a pay-per-use model. Business houses are progressively veering towards retaining core competencies, and shedding the non-core competencies for on-demand technology, business innovation and savings.

Delivery Options
• Infrastructure-as-a-Service (IaaS): Delivers computing hardware like Servers, Network, Storage, etc. Typical features are:
a) Users use resources but have no control of underlying cloud infrastructure
b) Users pay for what they use
c) Flexible scalable infrastructure without extensive pre-planning
• Storage-as-a-Service (SaaS): Provides storage resources as a pay-per-use utility to end users. This can be considered as a type of IaaS and has similar features.
• Platform-as-a-Service (PaaS): Provides a comprehensive stack for developers to create Cloud-ready business applications. Its features are:
a) Supports web-service standards
b) Dynamically scalable as per demand
c) Supports multi-tenant environment
• Software-as-a-Service (SaaS): Supports business applications of host and delivery type as a service. Common features include:
a) User applications run on cloud infrastructure
b) Accessible by users through web browser
c) Suitable for CRM (Customer Resource Management) applications
d) Supports multi-tenant environment

There are broadly three categories of cloud, namely Private, Hybrid and Public.

Private Cloud
• All components resident within user organization firewalls
• Automated, virtualized infrastructure (servers, network and storage) and delivers services.
• Use of existing infrastructure possible
• Option for management by user or vendor
• Works within the firewalls of the user organization
• Controlled network bandwidth
• User defines and controls data access and security to meet the agreed SLA (Service Level Agreement).

a) Direct, easy and fast end-user access of data
b) Chargeback to concerned user groups while maintaining control over data access and security

Public Cloud
• Easy, quick, affordable data sharing
• Most components reside outside the firewalls of user organization in a multi-tenant infrastructure
• Access of applications and storage by user, either at no cost or on a pay-per-use basis.
• Enables small and medium users who may not find it viable or useful to own Private clouds
• Low SLA
• Doesn’t offer a high level of data security or protection against corruption

Hybrid Cloud
• Leverages advantages of both Private and Public Clouds
• Users benefit from standardized or proprietary technologies and lower costs
• User definable range of services and data to be kept outside his own firewalls
• Smaller user outlay, pay-per-usage model
• Assured returns for cloud provider from a multi-tenant environment, bringing economies of scale
• Better security from high quality SLA’s and a stringent security policy

Future Projections and Driving User Segments

1. Media & entertainment – Enabling direct access to streaming music, video, interactive games, etc., on their devices without building huge infrastructure.
2. Social/collaboration – cloud computing enables more and more utilities on Face book, Linked-In, etc. With user base of nearly one-fifth of the world’s population, this is a major driving application
3. Mobile/location – clouds offering location and mobility through smart phones enable everything from email to business deals and more.
4. Payments – Payments cloud, a rather complex environment involving sellers, buyers, regulatory authorities, etc. is a relatively slow growth area

Overall, Cloud Computing is a potent tool to fulfill business ambitions of users, and with little competition on date, is poised for a bright future.

How to wipe a hard drive clean

If you are donating, disposing of or selling anything that contains a hard drive, chances are that drive should be wiped clean before it leaves your hands. Even if the hard drive has failed, special equipment can read a hard drive which could expose your private and confidential information to the next owner.

So what should you do before your dispose of your equipment with a hard drive? There are several methods that are recommended by the experts. Here is an explanation of two of them:

1 – Destruction:
According to the National Institute of Standards and Technology Special Publication 800-88, “Destruction of media is the ultimate form of sanitization.” Some methods to destroy a hard drive include pulverization, incineration, melting, and shredding however it should be noted that it is recommended that you never burn a hard drive, put a hard drive in a microwave, or pour acid on it in an effort to destroy it. Those methods should be avoided. What IS recommended is that you drive a nail through the hard drive, being sure to pierce the hard drive platter. This can be accomplished with a hammer and nails or even a drill. If you use this method to destroy the hard drive, drive several nails through or drill through it several times. Another method is to remove the hard drive platter and sand it to erase the data.

Destroying the hard drive ensures that you or anyone else will never be able to use the hard drive again. Should you want someone to be able to use the hard drive again, you might consider another option which is data destruction software.

2 – Data Destruction Software:

Sometimes called hard drive eraser software or disk wipe software, data destruction software is a way to remove your personal data off of a drive without permanently destroying the drive. While not a fool proof method (user error comes into play here), it is the easiest way to wipe a drive clean. Data destruction software overwrites a hard drive in a particular way to make extracting data from it very difficult, if not impossible. Most computer users should be able to safely wipe their hard drive clean using this type of software.

There are other methods available however they are generally expensive. Either of the two methods outlined above should suffice for the average computer user that would just like to wipe a drive clean before disposing of it.

Wired or wireless or both: What is best for small businesses?

Whether you are updating your office’s networking component needs or starting from scratch, there are many things to think about when you are considering wired vs wireless. For starters, ask yourself:

  • How many people are on your network? How about in 2 years?
  • How long will this system be in place? (any moves planned within 2 years?)
  • How fast does the network/internet access need to be right now? How about in 2 years?
  • What kind of files have to be moved across your network right now? How about in 2 years?
  • How fast does this need to be done?
  • Is this a temporary or permanent solution?
  • What is your budget?

Wiring a space can be cost prohibitive – especially if this space is temporary, but if the budget is unlimited, then hard wiring could be the way to go for speed and security. Very often a combination of both wired and wireless are the best solution.


When Does A Small Business Need A Server?

If your small business uses more than one computer to manage its business, you may be ready to upgrade to a small server to efficiently run your business.

Keep in mind that adding a server to your business is not a huge expense – in fact you can get started by putting an unused desktop computer to work, but the rewards go beyond the financial concerns.

Here’s how to recognize the signs that it’s time for you to invest in a server for your small business.

– Has your business grown beyond a few desktop computers, laptops and other data collectors including PDA’s?
– Is the thought of losing the company data that is stored on different computers making you uneasy? In fact, have you experienced a loss of data or incurred costs associated with the recovery of lost data?
– Do multiple employees need to access the same programs and documents?

If you answered yes to any of these questions, chances are your business is ready for a server.

Some of the benefits are that your business can use the server as a security gateway to regulate the different levels of access to your data, particularly for your employees. It is also possible to host your website on your company’s server but if your site has a reasonable amount of traffic, you might want to leave that alone.