Random Access Memory

Random-access memory (RAM) is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order with a worst case performance of constant time. Strictly speaking, modern types of DRAM are therefore not random access, as data is read in bursts, although the name DRAM / RAM has stuck. However, many types of SRAM, ROM, OTP, and NOR flash are still random access even in a strict sense. RAM is often associated with volatile types of memory (such as DRAM memory modules), where its stored information is lost if the power is removed. Many other types of non-volatile memory are RAM as well, including most types of ROM and a type of flash memory called NOR-Flash. The first RAM modules to come into the market were created in 1951 and were sold until the late 1960s and early 1970s. However, other memory devices (magnetic tapes, disks) can access the storage data in a predetermined order, because mechanical designs only allow this.

Types of RAM
Modern types of writable RAM generally store a bit of data in either the state of a flip-flop, as in SRAM (static RAM), or as a charge in a capacitor (or transistor gate), as in DRAM (dynamic RAM), EPROM, EEPROM and Flash. Some types have circuitry to detect and/or correct random faults called memory errors in the stored data, using parity bits or error correction codes. RAM of the read-only type, ROM, instead uses a metal mask to permanently enable/disable selected transistors, instead of storing a charge in them. Of special consideration are SIMM and DIMM memory modules. Because of economic reasons, personal computers, workstations and game consoles do not control large bits of data stored in DRAM. The computer's cache memory uses static RAM disks of data buffers.
SRAM and DRAM are volatile. Other forms of computer storage, such as disks and magnetic tapes, have been used as persistent storage. Many newer products instead rely on flash memory to maintain data when not in use, such as PDAs or small music players. Certain personal computers, such as many rugged computers and netbooks, have also replaced magnetic disks with flash drives. With flash memory, only the NOR type is capable of true random access, allowing direct code execution, and is therefore often used instead of ROM; the lower cost NAND type is commonly used for bulk storage in memory cards and solid-state drives. A memory chip is an integrated circuit (IC) made of millions of transistors and capacitors. In the most common form of computer memory, dynamic random access memory (DRAM), a transistor and a capacitor are paired to create a memory cell, which represents a single bit of data. The capacitor holds the bit of information — a 0 or a 1. The transistor acts as a switch that lets the control circuitry on the memory chip read the capacitor or change its state.

Swapping
If a computer becomes low on RAM during intensive application cycles, many CPU architectures and operating systems are able to perform an operation known as "swapping". Swapping uses a paging file, an area on a hard drive temporarily used as additional working memory. Excessive use of this mechanism is called thrashing and is generally undesirable because it lowers overall system performance, mainly because hard drives are far slower than RAM. However, if a program attempts to allocate memory and fails, it may crash.

How to install Mangal font in Microsoft XP?

Insert XP CD in your CD - Drive.
Go to the control panel.

Click on Regional and Language options, Click on Language tab.

Make check on both give option then click on OK button. File will be copy from XP CD in your system. It will take some time to copy. Your computer will be restart after copy.

Now, click on start button, go to the control panel, click on Regional and language options, Click on Language tab, click on Details button, now click on Add button

Select language in Hindi, Click on OK, OK and OK. Now you have installed Mangal font. Enjoy.............

Microsoft supports PPP model on cyber crime awareness

Technology giant Microsoft India supported a public-private partnership (PPP)-based model to generate awareness among people in India about cyber attacks, as more and more people are using social networking sites.

"Phishing attack (it uses email or malicious websites to solicit personal information) through social networks increased from a low of 8.3 per cent of all phishing in January to a high of 84.5 per cent in December, 2010," Microsoft said in its Security Intelligence Report, which highlights cyber attacks and the trend of attacks.

The company comes out with the report every six months. "The Indian government should come out with a PPP model which includes government, private organisations and NGOs in order to make people more aware of the cyber attacks and increase the level of security," Microsoft India Chief Security Officer Sanjay Bahl said.

For India, Bahl said although awareness among the people in India on cyber security-related issues is on the rise, there is ample scope to expand awareness, which can only be done through the PPP model.

"With more consumers and devices coming online every day, cybercriminals now have more opportunities than before to deceive users through attack methods like adware, phishing and rogue security software," Ovum Principal Analyst Graham Titterington said.

The report, which took into account the six-month period from June to December 30, 2010, indicates that in India, the most common category of cyber attacks was worms, which affected 42.5 per cent of all infected computers, down from 45.4 per cent in the last quarter.

The second-most common category in India was Miscellaneous Trojans, which affected 33.9 per cent of all infected computers, down from 34.5 per cent last quarter.

The third most common category in India was Miscellaneous Potentially Unwanted Software, which affected 33.7 per cent of all infected computers, up from 31.9 per cent in the last quarter.

Hackers hit Japanese video game maker Square Enix

As Sony battles to restore its PlayStation Network after suffering a data breach, hackers have hit Japanese video games maker Square Enix.

Hackers broke into three websites belonging to the game company and may have stolen the e-mail addresses of up to 25,000 customer registered for product updates and 350 job applicants, according to the BBC.

Square Enix - which makes the Final Fantasy, Deus Ex and Tomb Raider games - has confirmed hackers gained access to parts of its Eidosmontreal.com website and two product sites.


But Square Enix said in a statement that it does not hold any credit card data on its web servers. Square Enix added that here is no evidence the job application information has been distributed, and that the e-mail addresses are not linked to any additional personal information.

The company says it took the sites offline immediately to investigate how the intruders gained access and to increase security measures before allowing the sites to go live again.

Security experts say the latest breaches, like Sony's, could cause problems for those whose data has been stolen, exposing them to e-mail-based scams.

Security in the gaming industry has been in the spotlight in recent weeks since the Sony's PlayStation Network and Sony Online Entertainment multiplayer system were hacked.


Sony has been forced to seek external help to introduce several new security measures. Sony says its improved security measures include increased encryption levels, additional firewalls and an early warning system that will alert the company of any attempts to penetrate the network.

The company is attempting to restore its networks in a phased approach, but the process has been slowed by the high number of password reset request from users.

Sony has announced it will start restoring services in the Americas, Europe, Australia, New Zealand and the Middle East, and hopes to have all regions restored by the end of May.

But authorities in Japan say they will not allow Sony to re-activate its network until the anti-hacking measures it has announced are fully enacted and the company has taken adequate measures to ensure that users' credit card numbers and other private data will not be exposed through its online services again.

How to make an online wedding card?

Call it the latest technological 'tadka' to big fat Indian weddings — websites as marriage invites. They chronicle a couple's romantic journey, with photo galleries, and provide details like venue, schedule of events, guest list, contact point, travel arrangements, appropriate attire for various ceremonies, gift registries, and more. When Pune-based techie Debojyoti Kar took his 10-year-old courtship with sweetheart Nibedita to the next level, he did it in style. For Debojyoti, a software developer, creating a website was simple. "I always had the idea. You have a number of templates to choose from online. You can also personalize the site."

Vantage points
With friends and family scattered across the globe, it's one of the best ways to create a reference point for guests to seek information about the wedding. It also makes for a good prop for bonding between couples set to take their vows. As Anuradha Ramkrishnan, a housewife who got into this role only a month-and-a-half back, puts it, "When the internet plays such a pivotal role in almost everyone's life, why should a wedding announcement, probably the biggest event of one's life, stay behind?" Anuradha's husband Balakrishnan Subramanian, who works in Kolkata, says, "People are generally used to seeing a wedding invite in the form of a card or an e-mail. But creating a website to invite your loved ones is an innovative way of making your D-day special."

Take your pick
You can improvise on the basic templates. Anuradha says, "Once we registered ourselves with mywedding .com we started working on how our site should look and what the contents should be. We worked to bring together contents like our photos, 'about us' section , background music, the main invitation etc." Adds Debojyoti, "The one I chose provides a free account which would expire after the wedding. There's also an option of purchasing the website for an additional 90 days (which I opted for). You also have the option to maintain it for a longer term, which comes for a higher price."

Depending on your budget, you can have features like a couple's gallery, a blog and a live chat feature for travelling guests to post queries (manned by personnel equipped with the relevant information). Sudeep Ranjan, a faculty member with Maya Academy of Advanced Cinematics, Bangalore, says lots of links are available online from where we can download site templates. "But to access these or make changes to them one has to have basic knowledge of the softwares in which they can be edited. Subsequently, one can buy a webspace and get the site hosted or uploaded on the server," he says.

Wedding planner's perspective
Wedding planners too swear by the effectiveness of websites. Chennai-based wedding planner Vidya Gajapati Raj Singh says, "Such sites inform us about the couples' plans. With NRI clients, we meet when we begin to work with them, then the next we see of them would be just a couple of weeks before the wedding. The time leading up to this is when we do all our work and the website becomes a help." Wedding planner Lakshmi Rammohan, owner of Dreamweaver Weddings, Bangalore, says websites score high on the 'go green' front. "Wedding cards are certainly the least 'green' of all practices ," she says. But wedding cards aren't disappearing yet. Lakshmi says, "The essence of a wedding is a keepsake, something that can be preserved for posterity and wedding cards have no rival there. Wedding cards have textures, colours and certain physicality about them that no digital media can quite capture."

Adds Rajesh Bysani, who works with a Bangalore-based internet firm, "Elders still have some reservations. They believe in certain traditional practices and those can't be avoided. Distributing wedding cards is one such practice. Though setting up a website and e-invite did reduce the number of friends I had to give an invitation card to, family and relatives still had to be sent an invite the traditional way." Rajesh had 250 friends logging onto his website on the day, to witness the wedding live. "That was truly an amazing feeling. Friends and family from all over the world were a part of the wedding without being physically present there."

Scoring points
Websites make for a good reference point for friends and family attending a wedding Unlike paper cards, these make for a more interactive forum No scope of postal goof ups. It's all at the click of a mouse A lot more information can be fed into a website, as compared to an invitation card A great tool for wedding planners

Your GPS may not always be right

 
Travelers in the western US should not rely solely on technology such as GPS for navigation, authorities said, after a Canadian couple were lost in the Nevada wilderness for 48 days.

Albert Chretien, 59, and his wife Rita Chretien, 56, sought a shorter route between Boise, Idaho and Jackpot, Nevada during a road trip from British Columbia to Las Vegas.

Rita Chretien drank water from a stream and rationed meager supplies until hunters found her on Friday. Albert Chretien has been missing since March 22, when he went to seek help.

The Chretians mapped the route on their hand-held GPS, an electronic device tied to global satellites and commonly used for navigation.

Law enforcement and search and rescue officials said that too many travelers are letting technology lull them into a false sense of security.

"There are times when you need to put the GPS down and look out the window," said Howard Paul, veteran search and rescue official with the Colorado Search and Rescue Board, the volunteer organization that coordinates that state's missions.

Sheriff's offices in remote, high-elevation parts of Idaho, Nevada and Wyoming report the past two years have brought a rise in the number of GPS-guided travelers driving off marked and paved highways and into trouble.

The spike has prompted Death Valley National Park in California to caution on its web site that "GPS navigation to sites to remote locations like Death Valley are notoriously unreliable."

When two roads diverge in Western lands, take the one more traveled, authorities said.

"You've got people driving into the middle of a field because a machine showed a route that was shorter and quicker -- which it ultimately is not," said Rob DeBree, undersheriff in Albany County in southeastern Wyoming.

Searching for travelers who veer off an interstate highway in a county the size of Connecticut can be costly, time-consuming and dangerous for rescuers, he said.

Jerry Colson, sheriff of neighboring Carbon County, issued a broad appeal this winter to stay on paved roadways after several motorists consulted GPS devices for shortcuts and plowed into snowdrifts on roads to nowhere.

Authorities said such incidents show there is no substitute for common sense.

"Your machine may tell you the quickest route but it might not take into account there are impassable canyons between you and your destination," said Daryl Crandall, sheriff of Owyhee County in southwest Idaho.

Kevin McKinney, detective sergeant with the sheriff's office in Elko County, Nevada that is heading up the search for Albert Chretien, said motorists risk hardships on the patchwork of primitive roads in the wilds of northern Nevada where technology is ineffective.

Hard Disk Drive

A hard disk drive (HDD) is a non-volatile, random access device for digital data. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the platters.

Introduced by IBM in 1956, hard disk drives have fallen in cost and physical size over the years while dramatically increasing in capacity. Hard disk drives have been the dominant device for secondary storage of data in general purpose computers since the early 1960s. They have maintained this position because advances in their areal recording density have kept pace with the requirements for secondary storage. Today's HDDs operate on high-speed serial interfaces; i.e., serial ATA (SATA) or serial attached SCSI (SAS).

Capacity measurements

The capacity of hard disk drives is given by manufacturers in megabytes(1 MB = 1,000,000 bytes), gigabytes (1 GB = 1,000,000,000 bytes) orterabytes (1 TB = 1,000,000,000,000 bytes). This numbering convention, where prefixes like kilo- and mega- denote powers of 1000, is also used for data transmission rates and DVD capacities. However, the convention is different from that used by manufacturers of memory (RAM,ROM) and CDs, where prefixes like kilo- and mega- mean powers of 1024.

When the unit prefixes like kilo- denote powers of 1024 in the measure of memory capacities, the 1024ⁿ progression (for n = 1, 2, …) is as follows:

• kilo = 2¹⁰ = 1024¹ = 1024,
• mega = 2²⁰ = 1024² = 1,048,576,
• giga = 2³⁰ = 1024³ = 1,073,741,824,
• tera = 2⁴⁰ = 1024⁴ = 1,099,511,627,776

Data transfer rate

As of 2010, a typical 7200 rpm desktop hard drive has a sustained "disk-to-buffer" data transfer rate up to 1030 Mbits/sec.^[62] This rate depends on the track location, so it will be higher for data on the outer tracks (where there are more data sectors) and lower toward the inner tracks (where there are fewer data sectors); and is generally somewhat higher for 10,000 rpm drives. A current widely used standard for the "buffer-to-computer" interface is 3.0 Gbit/s SATA, which can send about 300 megabyte/s from the buffer to the computer, and thus is still comfortably ahead of today's disk-to-buffer transfer rates. Data transfer rate (read/write) can be measured by writing a large file to disk using special file generator tools, then reading back the file. Transfer rate can be influenced by file system fragmentation and the layout of the files.^[57]

HDD data transfer rate depends upon the rotational speed of the platters and the data recording density. Because heat and vibration limit rotational speed, advancing density becomes the main method to improve sequential transfer rates.^{[citation needed]} Areal density advances by increasing both the number of tracks across the disk and the number of sectors per track, the latter will increase the data transfer rate (for a given RPM). Since data transfer rate performance only tracks one of the two components of areal density, its performance improves at lower rate