Hello friends!
Welcome back! In our earlier blog we were reading about hard disk. Do you know where our data resides in a computer? Most of our data is stored in hard disk which is a secondary type of memory. RAM and ROM are the types of primary memory. Primary memory is an integral part of our CPU, whereas Secondary memory i.e hard disk, floppies, compact disks (CDs), digital versatile disks (DVDs), USB Drives are external.
The necessary instructions/programs which are required to initially start/run a computer resides in the ROM. These programs (set of instructions/commands) are stored in the Read Only Memory at the time of their manufacturing by its manufacturers, so it is also called Firmware. Its variations are 1.PROM Programmable ROM, that can be slightly programmed/changed by special device called ROM Programmer. Once programmed, then contents can not be changed 2. EPROM Erasable Programmable ROM i.e Its contents can be erased if required by a difficult process using ultra violet light rays, 3. EEPROM Electrically Erasable Programmable ROM, its contents can easily be changed by means of electric pulses.
RAM another type of primary/main memory is used by the processor of the computer as a scratch pad. The data remains in RAM until it is not saved. Once saved, data goes into Hard Disk of the computer. RAM is temporary memory. It is also called volatile memory because it retains data as longer as voltages are available to it. Once the computer is off it forgets every thing.The following are the variations of RAM.
RAM: Random Access Memory ( so called because processor can pick up the required data randomly which is necessary for maintaining the speed of computer or speedy execution of commands/instructions) Some times RAM is also called Read and Write Memory as unlike ROM data can both read and write from and on the RAM easily.
SRAM: Static RAM, requires constant refreshing by the electrical pulses at a much higher rates to retain data stored in it.
DRAM: Dynamic RAM, requires refreshing but less frequently, some more speedy than SRAM
SDRAM : Synchronous Dynamic RAM , this is the fastest of all types of RAMs
RAM and ROM are both types of memories are fabricated on a special type of semiconductor i.e Silicon chip. So also called Semiconductor memories.
In our next post we will know more about the memories. Enjoy reading till then. Yes do not forget to comment and let me know what you want to know about. Check out our website about the computers http://www.desirachh.in I have changed its looks and themes. Let me know whether you liked or some more suggestions may also be emailed to me: asiraj_67@operamail.com
Monday, September 22, 2008
Know your hardware (Memories)
Saturday, July 5, 2008
Graphics Card
Hello Friends!
In our past posts we were discussing about Video, its types. Then we discussed Monitor and its types. As you know monitor is used to display data, text or video, on its screen. But do you know monitor alone can't show us any thing without the help of a special hardware and that is Graphics Card. Today we will try to know what the Graphics card is and how it works.
It is a card that converts a computer’s digital data output into analogue form (in our past posts we also discussed about analogue and digital). We know computer only works on digital form of data but the monitor can't understand digital. It needs analogue data to work. Also we can also understand only analogue data. How will we feel when a picture or song or video is in the form 01110100?
The graphics card takes digital data from the CPU and RAM (Random Access Memory) inside the computer converts it into analogue signals and then sends them to the monitor. Which in turn is shown us.
Most graphics cards also are capable of doing more graphical computation/processing. It decreases the computing/processing load of CPU. These may be 3D computations required for the most of games played these days on computers and other gaming consoles.
When we move our mouse, it senses the movement and transfers the necessary data to the CPU. CPU translates it into X and Y coordinates (X and Y co-ordinates tell the position of anything on the screen of monitor) and send it to the graphics card or video adapter, which in turn, moves the mouse pointer displayed on our screen. As this is done in millionths of a second, when we move our mouse, it appears to move smoothly across screen of monitor. It seems like a video playing. This is the basic principle for digital video that we see everyday on our computer!
I think you have understood the working of Graphics card. If you have any question regarding this or other topic about computers feel free to comment or email me asiraj_67@operamail.com
Rajesh
www.desirachh.ws
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