Basic computer in detail with pictures created by creativeness
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A computer is an electronic device that can be programmed to perform logical and arithmetic operations. It consists of a central processing unit (CPU) and memory. The CPU contains an arithmetic logic unit that performs calculations and a control unit that directs operations. Memory stores programs and data. Peripheral devices allow information to be input and output. Early computers were room-sized, while modern computers are integrated circuits that can fit into mobile devices. Personal computers are ubiquitous and embedded computers are in many devices.
![• The control unit (often called a control system or central controller) manages the computer's
various components; it reads and interprets (decodes) the program instructions, transforming them
into a series of control signals which activate other parts of the computer. [43] Control systems in
advanced computers may change the order of some instructions so as to improve performance.
• A key component common to all CPUs is the program counter a special memory cell (a register
that keeps track of which location in memory the next instruction is to be read from. [44]
• The control system's function is as follows—note that this is a simplified description, and some of
these steps may be performed concurrently or in a different order depending on the type of CPU:
Read the code for the next instruction from the cell indicated by the program counter.
Decode the numerical code for the instruction into a set of commands or signals for each of the
other systems.
Increment the program counter so it points to the next instruction.
Read whatever data the instruction requires from cells in memory (or perhaps from an input
device). The location of this required data is typically stored within the instruction code.
Provide the necessary data to an ALU or register.
If the instruction requires an ALU or specialized hardware to complete, instruct the hardware to
perform the requested operation.
Write the result from the ALU back to a memory location or to a register or perhaps an output
device.
Jump back to step (1).
• Since the program counter is (conceptually) just another set of memory cells, it can be changed by
calculations done in the ALU. Adding 100 to the program counter would cause the next instruction
to be read from a place 100 locations further down the program. Instructions that modify the
program counter are often known as “jumps” and allow for loops (instructions that are repeated by
the computer) and often conditional instruction execution (both examples of control flow).
• The sequence of operations that the control unit goes through to process an instruction is in itself
like a short computer program, and indeed, in some more complex CPU designs, there is another](https://image.slidesharecdn.com/basiccomputer-140211092353-phpapp01/85/Basic-computer-in-detail-with-pictures-created-by-creativeness-7-320.jpg)
Basic computer in detail with pictures created by creativeness
- 2. Computer • A computer is a general purpose electronic device that can be programmed to carry out arithmetic or logical operations. • computer can solve more than one kind of problem with readily changed sequence of operations • Conventionally, a computer consists of a central processing unit (CPU) and some form of memory . • Processing element carries out arithmetic and logic operations • Sequencing and control unit change the order of operations based on stored information
- 3. Computer • Peripheral devices such as printer scanner speaker web camp allow information to be retrieved from an external source, and the result of operations saved and retrieved. • The first electronic digital computers were developed between 1940 and 1945. Originally as big as a large room, consuming as much power as several hundred modern personal computers (PCs). • In this era mechanical analogy computers were used for military applications. • Modern computers based on integrated circuits are millions to billions of times more capable than the early machines, and occupy a fraction of the space.
- 4. Computer • Simple computers are small enough to fit into mobile devices, and mobile computers can be powered by small batteries. • Personal computers in their various forms are icons of the Information Age and are what most people think of as “computers.” • Embedded computers found in many devices from MP3 players to fighter aircraft and from toys to industrial robots are the most numerous.
- 6. Components • A general purpose computer has four main components: the arithmetic logic unit (ALU), the control unit, the memory, and the input and output devices (collectively termed I/O). These parts are interconnected by buses, often made of groups of wires. • Inside each of these parts are thousands to trillions of small electrical circuits which can be turned off or on by means of an electronic switch. Each circuit represents a bit (binary digit) of information so that when the circuit is on it represents a “1”, and when off it represents a “0” (in positive logic representation). The circuits are arranged in logic gates so that one or more of the circuits may control the state of one or more of the other circuits. • The control unit, ALU, registers, and basic I/O (and often other hardware closely linked with these) are collectively known as a central processing unit (CPU). Early CPUs were composed of many separate components but since the mid-1970s CPUs have typically been constructed on a single integrated circuit called a microprocessor. •
- 7. • The control unit (often called a control system or central controller) manages the computer's various components; it reads and interprets (decodes) the program instructions, transforming them into a series of control signals which activate other parts of the computer. [43] Control systems in advanced computers may change the order of some instructions so as to improve performance. • A key component common to all CPUs is the program counter a special memory cell (a register that keeps track of which location in memory the next instruction is to be read from. [44] • The control system's function is as follows—note that this is a simplified description, and some of these steps may be performed concurrently or in a different order depending on the type of CPU: Read the code for the next instruction from the cell indicated by the program counter. Decode the numerical code for the instruction into a set of commands or signals for each of the other systems. Increment the program counter so it points to the next instruction. Read whatever data the instruction requires from cells in memory (or perhaps from an input device). The location of this required data is typically stored within the instruction code. Provide the necessary data to an ALU or register. If the instruction requires an ALU or specialized hardware to complete, instruct the hardware to perform the requested operation. Write the result from the ALU back to a memory location or to a register or perhaps an output device. Jump back to step (1). • Since the program counter is (conceptually) just another set of memory cells, it can be changed by calculations done in the ALU. Adding 100 to the program counter would cause the next instruction to be read from a place 100 locations further down the program. Instructions that modify the program counter are often known as “jumps” and allow for loops (instructions that are repeated by the computer) and often conditional instruction execution (both examples of control flow). • The sequence of operations that the control unit goes through to process an instruction is in itself like a short computer program, and indeed, in some more complex CPU designs, there is another