Main elements of Micro computers

Computer with a technology introduced with microprocessor as its central processing unit are called Micro computers. Comparitively they occupy physically less space than mainframe and minicomputers. Microcomputers are designed to be used by individuals, whether in the form of PCs, workstations or notebook computers. A microcomputer contains a microprocessor, a memory system typically storage memory and random access memory, a bus system and I/O ports, provided in a motherboard.

The main elements of Microcomputers are

1. Microprocessor
2. Memory
3. Motherboard
4. Peripherals

Microprocessor:

A microprocessor is a computer processor on a microchip. It's sometimes called a logic chip. It is a complete computation engine that is fabricated on a single chip. A microprocessor is designed to perform arithmetic and logic operations that make use of small number-holding areas called registers. This sits on the motherboard of each Personal computer.

Memory:

Is the internal storage areas in the computer. The term memory identifies data storage that comes in the form of chips i.e. RAM, and the word storage is used for memory that exists on tapes or disks i.e. Hard drive.

RAM:
Stands for Random access memory. Its purpose is to store the information and instructions that operate the computer's programs. Typically, programs are transferred from storage on a disk drive to RAM. Random-access memory is also known as volatile memory because the information within the computer chips is lost when power to the computer is turned off.

A more recent development is solid-state RAM. Unlike standard RAM, solid state RAM can contain information even if there is no power supply. Flash drives are removable storage devices that utilize solid-state RAM to store information for long periods of time. There are mainly two types of RAM i.e. Dynamic RAM (DRAM) and Static RAM (SRAM), comparatively DRAMs are slower and cumbersome than SRAM which are faster, expensive and can hold more information.

Random Access Memory could be considered as an array of boxes, where each box holds a single byte of information. A computer having one megabyte of memory can hold up to one million bytes or characters of information. The speed of RAM is measured in nanoseconds (ns). Lesser the nanoseconds, faster the speed of the computer.

Hard Drive:
Stores and provides relatively quick access to large amounts of data on an electromagnetically charged surface or set of surfaces. Microcomputers typically come with a hard disk that contains several billion bytes.


A hard disk is a set of disks, each of which has data recorded electromagnetically in concentric circles or tracks on the disk. A head writes or reads the information on the tracks. Two heads, one on each side of a disk, read or write the data as the disk spins. Each read or write operation requires that data be located, which is an operation called a seek.
A hard disk/drive unit comes with a set rotation speed varying from 4500 to 7200 rpm. Disk access time is measured in milliseconds. Although the physical location can be identified with cylinder, track, and sector locations, these are actually mapped to a logical block address that works with the larger address range on today's hard disks.


Motherboard:

A motherboard allows all the parts of a Micro computer to receive power and communicate with one another.
The motherboard's main job is to hold the computer's microprocessor chip and let everything else connect to it. Everything that runs the computer or enhances its performance is either part of the motherboard or plugs into it via a slot or port.


The motherboard contains the connectors for attaching additional boards. Typically, the motherboard contains the CPU, BIOS, memory, mass storage interfaces, serial and parallel ports, expansion slots, and all the controllers required to control standard peripheral devices, such as the display screen, keyboard, and disk drive. Collectively, all these chips that reside on the motherboard are known as the motherboard's chipset.

Motherboard designs use many different buses to link their various components. For instance, wide, high-speed buses are difficult and expensive to produce. The signals travel at such a rate that even distances of just a few centimeters cause timing problems, while the metal tracks on the circuit board act as miniature radio antennae, transmitting electromagnetic noise that introduces interference with signals elsewhere in the system. For these reasons, design engineers try to keep the fastest buses confined to the smallest area of the motherboard and use slower, more robust buses for other parts.

Peripherals:

Any device that is attached to the computer is considered a peripheral. Examples include the printer, monitor, and mouse. Information and commands are transferred from the computer to the peripheral device through controllers, which are often single chips. Controllers for items like the keyboard and disk drives are standard, while additional devices such as a modem usually require the insertion of new controllers from the expansion board. Furthermore, the bus (series of connected wires that connects peripherals with the computer) must be compatible with the controller. There are three basic types of bus architectures.
The AT bus, PCI and SCSI.