Basic Hardware Elements
There’s a lot of Computer hardware in the world. Here’s a little bit of Basic hardware elements your basic knowledge.
(1) Central Processing Unit (CPU)
The CPU is the brain within your computer. It performs most of the computer calculations and is responsible for the smooth running of your operating system (Microsoft Windows) as well as your application programs. There is a small amount of memory associated with the CPU, which it uses to perform these operations (Cache memory). It also accesses and uses the main memory (RAM – Random Access Memory) within your computer. In many ways, the CPU is the single most important item within your computer that governs the overall speed of your computer.
It consists of :
- Arithmetic and Logic Unit (ALU) :- which performs the calculations and comparisons.
- Control Unit (CU) :- controls the other parts of the computer.
- Register :- very high speed memory slots used to hold temporary results.
- Cache Memory :- high speed buffer memory used to enhance the data transfer from the RAM.
The CPU speed is mainly determined by its internal clock speed which triggers the other circuits. This clock speed is measured in Hertz (HZ). These days typically in Giga Hertz (GHz).
The computer needs a working memory for storing the current programs it runs. That is the data and instructions it uses. This working memory is called the main memory or primary storage. Although this memory is divided into two parts RAM and ROM. Normally when people talk about memory in relation to PC, they talk about the RAM.
(I) Random Access Memory (RAM) : RAM is the main working memory used by the Computer. When the operating system loads from the disk when you first switched on the computer. It is copied into the RAM. Modern computers can effectively house as much RAM as you can afford to buy. Commonly modern computers are supplied with over 2 GB of RAM. Data and programs stored in the RAM are volatile (the information is lost when you switch off the computer).
(II) Read Only Memory (ROM) : Read Only Memory (ROM) as the name suggests is a special type of memory chip that holds software that can be read but not written to. A good example is the ROM – BIOS chip which contains read – only software that starts up your computer.
(III) Video Graphics Memory
The picture that you see on your screen is a form of data and this data has to be stored somewhere. The on-screen pictures are held in a special memory chip called Video Memory Chip; these chaps are usually located on a video card. A modern computer will be supplied with several megabytes of video memory.
Computer memory capacity
All digital computers work on a binary numbering system. i.e. they process data in ones or zeros. These 1 or 0 levels of storage is called a bit and memory capacity is measured in multiplies of bits. Often hardware is specified as a 32 – bit computer, which means that the hardware can process 32 bits at a time.
- 8 bits = 1 byte
- 1024 bytes = 1KB (Kilobyte)
- 1024 KB = 1MB (Megabyte)
- 1024 MB = 1GB (Gigabyte)
- 1024 GB = 1TB (Terabyte)