What is RAM?

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What is RAM?

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Category : Hardware , Tech Tips

RAM is a moniker for Random Access Memory. It acts as a short-term memory much like the human brain to store a wealth of information. The RAM is accessible through the computer’s brain called the CPU which stands for Central Processing Unit. RAM has the capability of being retrieved only while a computer is on. When the computer is turned off the RAM is no longer accessible. ROM chips along with BIOS (computer boot firmware) allows the RAM information to be retrievable when the computer is rebooted.

Most computers come equipped with 2 gigabytes of RAM already on the computer. Additional RAM can be placed within the system. However, there is usually a limitation placed upon just how much RAM can be added to a computer system. RAM is not random as its name would lead one to believe. The RAM is highly controlled and the storage can be directly ascertained. There is a decisive method that RAM utilizes to make its memory available to certain areas of the computer system.

Forms for RAM

RAM is what is known as discrete microchips which means that it is separate from the rest of the computer and motherboard. An additional form of RAM is modules which attach into outlets in the motherboard of the computer. A network of electrical pathways to the processor allows the connection to spark for the RAM.

Why is RAM Important

RAM serves the very important function of retrieving information that must be accessed in a quick manner. This operation is very similar to the human brain’s function in retrieving necessary facts from short term memory. Open files and the utilization of applications on a computer systems requires the assistance of RAM. Users that play alot of video games with detailed graphics or keep alot of folders open while on their computer, will need the use of additional RAM. This will allow them to better access the information they need when the time comes. RAM is held onto a limited time, but it allows the information to come up quickly and without much fuss on the part of the computer user.


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What is EProm?

EPROM or Erasable Programmable Read Only Memory is rewritable memory chip that can hold its data without power. A programmed EPROM can keep its data for up to twenty years and can be read indefinite number of times. An Israeli engineer, Dov Frohman invented the EPROM chip in 1971.

EPROM chips are embedded on an external programming device before being used on the circuit board. The EPROM chip requires a costly ceramic chip package with a small quartz window that is sheltered with opaque, sticky tape. For reprogramming, the chip is extracted from the circuit board, the tape is detached and it is placed below a concentrated ultraviolet (UV) light of wavelength 235nm light for approximately 20 minutes.

Some microcontrollers, before the era of EEPROMs and flash memory, used EPROM to store their program. Such microcontrollers include some versions of the Intel 8048, and the “C” edition of the PIC microcontroller. Similar to EPROM chips, such microcontrollers came in windowed (expensive) versions that were handy for debugging and program development. Leaving the die of such a chip exposed to sunlight can change its behavior in unexpected ways.

EPROMs come in several sizes with regard to both packaging and storage capacity. Parts of the same type of EPROM from different manufacturers are intercompatible as long as they’re only being read, there are subtle differences in the programming process.

Most EPROMs can be identified by the programmer by forcing 12V on pin A9 and reading the two bytes of data. However, programmer software would allow manual setting of the chip to ensure proper programming.

EPROMs are the forerunners of the modern EEPROMs and flash memory.


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Memory Stick Speeds Explained

In a few short years since the launch of the first 4Mb flash memory card, the number of flash memory cards, aka SD Cards, available for digital cameras and other devices has exploded with a number of different formats and speeds of memory card. It’s no wonder the average person is totally baffled by this plethora of memory cards.

Not only are there different shapes (the format) and sizes of memory sticks such as Secure Digital (SD) Compact Flash, Memory Stick, etc, but also different speed ratings.

Memory card speed is the card’s performance with regard to how quickly data can be transferred to or from it. The card speed is often stated in ‘Times’ ratings i.e. 12X, 40X etc (just as the speed of recordable CD’s and DVD’s is measured), and sometimes more specifically in megabytes per second (Mb/s). By today’s measure, sub 30X represents a standard speed, 30X to 60X is mid-high speed and over 66X is high speed. The chart below shows the relationship between the two figures.

8X = 1.2 Mb/sec
12X = 1.8 Mb/sec (Also known as Class 2 for SD Cards)
20X = 3.0 Mb/sec
25X = 3.8 Mb/sec (Also known as Class 4 for SD Cards)
30X = 4.5 Mb/sec
40X = 6.0 Mb/sec (Also known as Class 6 for SD Cards)
60X = 9.0 Mb/sec
66X = 10.0 Mb/sec (Also known as Class 10 for SD Cards)
80X = 12.0 Mb/sec
90X = 15.0 Mb/sec
133X = 20.0 Mb/sec

Why do we need different or higher speeds cards?
This is mainly due to the advancement of our digital devices, especially digital cameras, camcorders and music devices. As manufacturers develop higher and higher spec devices (i.e. higher resolution cameras and more intense multi-media functions), they are creating increasingly larger amounts information to store pictures, movies, music and so on. This in turn takes longer to record onto the memory card. For example if you have ever used a high megapixel camera with a standard speed card you may have noticed the time lag between pressing the shutter button and being able to take the next picture. This lag or delay, in most cases, is caused by a slow write speed. Similarly, copying your photos to your PC could take time too and is caused by a slow read speed.
So who really needs high-speed memory cards?
Professional photographers and enthusiasts using professional grade cameras such as digital SLR’s should use high-speed memory cards of at least 40X speed. If you own a camera with a megapixel rate above ten million pixels, you will certainly benefit from a card with a higher speed rating. If you’re like most of us using a compact camera under ten million pixels, you’ll get great performance from standard cards with 25X or more.

Those using digital camcorders and devices recording MP3 music or video will also benefit from higher speed cards. It used to be where very few people would actually benefit from very high-speed cards. Typically only professionals who used expensive, specialized products benefited, but it’s fast becoming a requirement on many of the latest PDA’s, Cameras, phones and other mobile devices to make use of the extra speed made available by high speed cards.

People using high speed memory cards with equipment that has been on the market a while may not notice any difference in performance, but this has more to do with the limitations of the device than the flash card itself. This is because not only does your memory card have a maximum speed rating, but your camera or mobile phone will also have its own speed rating. When these products are combined, they’ll work at the “slowest common denominator” e.g. if you use a 12X flash card in a camera with a designed for a maximum of 8X speed, you’ll be transferring data at the slower 8X speed.

You should always check the capacity of your device before splurging on mega fast cards, but determining the speed compatibility of your device can be tricky. Most manuals just don’t tell you what speed of flash card you should use, now that would be far too easy, but they do tell you to buy their brand, which isn’t much help! So a general rule of thumb, if your camera is less than three megapixels the speed rating of the flash card doesn’t matter much. Most modern cameras have the ability to support far higher speeds than the cards available to purchase today, therefore, if speed is of importance, go for a faster card. Most mobile phones are fine with standard speed cards although some newer models will benefit from higher speed cards but not generally over 60X speeds. Hope this info helps you pick your next SD Card wisely.

 


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What is a Pen Drive?

A Pen Drive is a removable storage device that plugs into a computer’s USB port. Small enough to carry on a key ring, Pen Drives are great for transferring photos, music, documents and any other data from one computer to another. Different manufacturers over the years have named their Pen Drives with many different names causing constant confusion.
As a result of this the Pen Drive can also be known as Pocket Drive, Thumb Drive, Jump Drive, USB Flash Drive, USB Flash Memory Drive, USB Key Drive, USB Memory Key and USB Memory Stick among many others!

Although none of these names are either correct or incorrect, one of the names cause a huge amount of confusion for people, this is when someone referring to a Pen Drive, uses the term “Memory Stick”. This is because “Memory Stick” is a Sony trademark and refers to a type of memory card used in Sony’s electronic devices, it is therefore a completely different product, which will not plug directly into your computer’s USB port!

Pen Drives were invented by IBM in 1988 as a replacement to Floppy Disks but were never patented by them, M-Systems who were later contracted in by IBM to manufacture Pen Drives actually own the patent. So think of a Pen Drive as a modern day floppy disk. The main difference being that a floppy disk contains moving parts which can make the data stored on it vulnerable, a Pen Drive is solid state meaning there are no moving parts inside, making it resilient to dust and everyday magnetic fields and so a safer storage option. Also Pen Drives can hold much, much more data than the floppy disk.

Once connected to a computer’s USB port the Pen Drive appears in Windows as a “Removable Drive” alongside your C Drive, CD ROM Drive etc. You can simply drag and drop photos, music, documents and any other type of data on to the “Removable Drive” just as would with any other folder on your computer (no complex recording like CD or DVD is required). The Pen Drive can then be removed (see Safe Removal of Pen Drive below) from the computer and plugged into another computer’s USB port giving you access to the information you copied to the Pen Drive.

The compact size, robust nature and low cost of the Pen Drive has made it a big hit and an indispensible tool for many. It is ideal for transporting personal, or work data from one location to another, i.e. from home to school or office, or for carrying around data that someone may want to access in a variety of places. An insurance company in the US loads customer bio data and policy details on a tiny Pen Drive and advises policy holders to wear it with a neck strap in case of emergencies, another company is doing the same with policy holders who go Sking. Another company videos their conference and records it onto the Pen Drive so that the delegates can refer to it in future. Pen Drives can also be used to back up your important documents.