Computers and Microprocessors

Computers:

Are the machine that performs tasks, such as mathematical calculation or electronic communication, under the control of a set of instructions called a program. Programs usually reside within the computer and are retrieved and processed by the computer’s electronics, and the program results are stored or routed to output devices such as video display monitors or printers. Computer performs tasks with reliability, accuracy and speed. They are the devices that compute, perform high-speed mathematical or logical operations or that assemble, store and process information. Generally it is a device that receives, processes, and presents information.

Types:
The two basic types of computers are analog and digital. Although generally not regarded as such, the most prevalent computer is the simple mechanical analog computer.
An analog computer uses inputs that are proportional to the immediate value of variable quantities, combines these inputs in a programmed way, and produces outputs that are a continuously varying function of the inputs and the processing. These outputs are then displayed.
On the other hand, a digital computer uses symbolic representations of its variables. The arithmetic unit is constructed to follow the rules of one number systems. Further, the digital computer uses individual discrete states to represent the digits of the number system chosen. A digital computer can easily store and manipulate numbers, letters, images, sounds, or graphical information represented by a symbolic code.
Working:
The tangible parts of computer are known as hardware. They includes the memory that store data along with instructions. The central processing unit carries out instructions, Buses are used to connect different components such as the input devices like keyboard or mouse which allow user to communicate; and the output devices like printers and display monitor which enable computer to present information.
Programs which run the computer and tell the hardware how to work are called software. It’s generally designed to perform a particular task. E.g. to write a letter, to draw a graph or to direct the general operation of the computer.


System Box: Basically the system box is composed of central processing unit, Random access memory, hard disk drive and Motherboard.


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. The motherboard stands for the card in the PC that controls almost all the other peripherals.

Microprocessor operation:
Typical microprocessor operations include adding, subtracting, comparing two numbers, and fetching numbers from one area to another. These operations are the result of a set of instructions that are part of the microprocessor design. When the computer is turned on, the microprocessor is designed to get the first instruction from the basic input/output system that comes with the computer as part of its memory. After that, the BIOS loads the operating system into computer memory.

Architecture:
The microprocessor contains the arithmetic logic unit (ALU) and the control unit for a microcomputer. It is connected to memory and I/O by buses which carry information between the units


First Microprocessor:
The first microprocessor was the Intel 4004, introduced in 1971. The 4004 was not very powerful -- all it could do was add and subtract, and it could only do that 4 bits at a time. But it was amazing that everything was on one chip. Prior to the 4004, engineers built computers either from collections of chips or from discrete components.
Leading companies of microprocessor manufacturers include the Intel and AMD processors.