Thursday, October 29, 2015
HARD DRIVE
In computing, a video card (also called a graphics card or a graphics accelerator) is a special circuit board that controls what is shown on a computer monitor and calculates 3D images and graphics.
A video card can handle two types of video images. First, they can be used to display a two-dimensional (2D) image like a Windowsdesktop, or a three-dimensional (3D) image like a computer game. Computer-Assisted Drawing (CAD) programs are often used by architects and designers to create 3D models on their computers. If a computer has a very fast video card, the architect can create very detailed 3D models.
Many computers have a basic video and graphics capabilities built-in to the computer's motherboard. These "onboard" video chips are not as fast as normal graphics cards. They are fast enough for basic computer use and even some basic computer games. If a computer user wants faster and more detailed graphics, a video card can be installed.
Video cards have their own processor (called a Graphics Processing Unit or GPU). The GPU separate from the main computer processor (called the Central Processing Unit or CPU). The CPU's job is to process all the calculations needed to make the computer function. The GPU's job is to handle 3D graphics calculations so the CPU does not have to. 3D graphics calculations take a lot of CPU power, so having a video card to handle the graphics calculations lets the CPU focus on other things like running computer programs.
Video cards also have their own memory, separate from the main computer memory. It is usually much faster than main computer memory, too. This helps the GPU do its graphics calculations even faster. Most video cards also allow more than one monitor to be plugged in at one time. This lets the computer user use more than one monitor at once. Graphics manufacturers nVidia and ATI have special technologies that allow two identical cards to be linked together in a single computer for much faster performance. nVidia calls their technology SLI and ATI calls their technology CrossFire. Some modern graphics cards can even process physics calculations to create even more realistic-looking 3D worlds.
Video cards typically connect to a motherboard using the Peripheral Component Interconnect (PCI), the Advanced Graphics Port (AGP) or the Peripheral Component Interconnect Express (PCI Express or PCI-E). PCI-E is the newest and fastest connection; most (if not all) new video cards and motherboards have this connection. Before PCI-E was used, AGP was the standard connection for video cards. Before AGP, video cards were designed for PCI (sometimes called "regular" PCI).
Computer Memory
The computer memory is a temporary storage area. It holds the data and instructions that the Central Processing Unit (CPU) needs. Before a program can be run, the program is loaded from some storage medium into the memory. This allows the CPU direct access to the program. Memory is a need for any computer.
A computer is usually an electrical device, which understands only electricity on and electricity off. This is expressed by using two symbols – 0 and 1 – which are called binarydigits or bits. Numbers and text characters are represented as codes, which are made up of combinations of 0s and 1s. Simple character codes are called ASCII (the American Standard Code for Information Interchange), and Unicode. In ASCII, eight bits – any combination of 0s and 1s – form one character or symbol. For example, the letter A is denoted by the code 01000001. The basic working unit of the computer's memory is a group of eight bits, which is called a byte.
The computer's memory consists of many millions of bytes. To make it easier, the unit K (for kilobytes) can be used to express memory capacity. One K equals 1,024. For example, 64K bytes of memory is the same as 65,536 (1,024 × 64 = 65,536) bytes. For larger memory capacities, the units mega and giga can be used. One megabyte of computer memory usually means 1024 kilobytes, which is 1,048,576 bytes, whereas one gigabyte means 1024 megabytes, which is 1,073,741,824 bytes.
The CPU calls instructions and data from the computer's memory. Because the same computer performs different tasks at different times, the memory is erasable—much likeaudio cassette. But there are some programs and instructions which the computer needs. It does not matter what function you are performing. These programs often are permanently recorded in the memory. So they cannot be destroyed. As a result, the computer's memory usually consists of two parts:
Random Access Memory
Random access memory (RAM) is used as the
working memory of a computer system. It stores input data, intermediate
results, programs, and other information temporarily. It can be read and/or
written. It is usually volatile, that is all data will be lost when the power
is turned off. In most cases it is loaded again from hard disk which
is used as data storage.
Read only memory
Read only memory (ROM) is the permanent memory
which is used to store important control programs and systems software to
perform a variety of functions, such as bootingup
or starting up programs. ROM is non-volatile. That means the contents are not
lost when the power is switched off. Its contents are written at the time of
manufacture, but in modern (2012) computers may be changed using special
software.
Wednesday, October 7, 2015
The Motherboard
A motherboard (sometimes alternatively known as the mainboard, system board, planar board or logic board,[1] or colloquially, amobo) is the main printed circuit board (PCB) found in computers and other expandable systems. It holds and allows communication between many of the crucial electronic components of a system, such as the central processing unit (CPU) and memory, and provides connectors for other peripherals. Unlike a backplane, a motherboard contains significant sub-systems such as the processor and other components.
Motherboard specifically refers to a PCB with expansion capability and as the name suggests, this board is often referred to as the "mother" of all components attached to it, which often include sound cards, video cards, network cards, hard drives, or other forms of persistent storage; TV tuner cards, cards providing extra USB or FireWire slots and a variety of other custom components (the termmainboard is applied to devices with a single board and no additional expansions or capability, such as controlling boards in televisions, washing machines and other embedded systems).
The Processor
A central processing unit (CPU) is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logical, control and input/output (I/O) operations specified by the instructions. The term has been used in the computer industry at least since the early 1960s.[1] Traditionally, the term "CPU" refers to a processor, more specifically to its processing unit and control unit (CU), distinguishing these core elements of a computer from external components such as main memoryand I/O circuitry.[2]
The form, design and implementation of CPUs have changed over the course of their history, but their fundamental operation remains almost unchanged. Principal components of a CPU include the arithmetic logic unit (ALU) that performs arithmetic and logic operations,processor registers that supply operands to the ALU and store the results of ALU operations, and a control unit that fetches instructions from memory and "executes" them by directing the coordinated operations of the ALU, registers and other components.
Most modern CPUs are microprocessors, meaning they are contained on a single integrated circuit (IC) chip. An IC that contains a CPU may also contain memory, peripheral interfaces, and other components of a computer; such integrated devices are variously calledmicrocontrollers or systems on a chip (SoC). Some computers employ a multi-core processor, which is a single chip containing two or more CPUs called "cores"; in that context, single chips are sometimes referred to as "sockets".[3] Array processors or vector processorshave multiple processors that operate in parallel, with no unit considered central.
Subscribe to:
Comments (Atom)