This document provides an overview of the key components and operations of a basic computer system. It discusses that a computer is a programmable machine that can perform arithmetic and logical operations automatically. The three main components are the input, processing, and output units. The input unit accepts instructions and data and converts it to a computer-readable format. The processing unit, or central processing unit (CPU), carries out the program instructions and includes an arithmetic logic unit (ALU) and control unit. The output unit converts results into a human readable format. Other components discussed include primary memory (RAM), secondary memory (hard disks), and storage units that hold data and instructions.
2. WHAT IS A COMPUTER ?
A Computer is a machine that can be programmed to
carry out sequences of arithmetic or logical operations
automatically. Modern computers can perform
generic sets of operations known as programs. These
programs enable computers to perform a wide range
of tasks. A computer system includes the hardware,
operating system and peripheral equipment.
Characteristics of a computer are – Speed, Accuracy, Cost
Effectiveness, Diligence, Storage Capacity,
Versatility, Time Saving, Automation and Security.
Limitations of a computer are – Zero I.Q., Lack in
decision making power and Dependence on
external {electricity} power.
3. DESIGN OF A COMPUTER SYSTEM
A computer responds to a set of instructions in a
well-defined manner. It executes a list of
instructions called Program.
HARDWARE :- The physical components of a
computer system that can be felt, seen and
touched are called Hardware.
SOFTWARE :- It is a collection of computer
programs, procedures and documentations
that perform certain tasks using the hardware
components.
4. IPO CYCLE
The IPO Cycle is defined as a computer procedure for the processing of
information. In computation, it is a critical process through which users get the
desired outcome. It comprises mainly of three elements; input, process, and
output.
5. OPERATIONS OF A COMPUTER
Five basic operations of a computer system are:
Inputting - This is the act of feeding in the data and instruction to the
computer.
Processing - The task of performing calculations and comparisons are known
as processing.
Outputting – It is the process showing out results of an operation.
Storing – It is the process of storing and saving of data and instructions.
Controlling – It is process of managing the order or the sequence in which the
above operations will be performed.
6.
7. INPUT UNIT
It accepts (or reads) instructions and data from outside. It converts these
instructions and data in computer acceptable form. It supplies the converted
instructions and data to the computer system for further processing.
8. OUTPUT UNIT
It accepts the results produced by the CPU. It converts these coded results to
human acceptable form. It supplies the converted results to outside world.
9. STORAGE UNIT
When a user enters data using input devices, the computer system stores this
data in memory unit i.e. Storage Unit. The storage unit uses a set of pre-
programmed instructions to further transmit this data to other parts of CPU.
Storage units of all the computers are comprised of two types of memories:
Primary Memory and Secondary Memory.
10. PRIMARY MEMORY
Primary Memory is computer memory that a processor or computer accesses
first or directly. It allows a processor to access running execution applications
and services that are temporarily stored in a specific memory location. Primary
memory is also known as Main Memory. It compromises of two types of
memory technology, i.e. ROM(Read Only Memory) and RAM(Random Access
Memory).
11. SECONDARY MEMORY
Secondary Memory as it is not directly accessible through the CPU and is non-
volatile. Secondary devices have a much larger storage capacity and the cost of
secondary memory is less as compared to primary memory. It is also called
Permanent Storage. USBs, DVDs, CDs, Blu-Ray Disc are example of Removable
Storage Secondary Memory Media whereas the Hard Disk Drive and Floppy
Disc are examples of Fixed Storage Secondary Memory Media.
12. CENTRAL PROCESSING UNIT (CPU)
A Central Processing Unit (CPU), also called a Central Processor, is the
electronic circuitry that executes instructions comprising a computer program.
The CPU performs basic arithmetic, logic, controlling, and input/output (I/O)
operations specified by the instructions in the program. This contrasts with
external components such as main memory and I/O circuitry. Control unit (CU)
and Arithmatic Logic Unit (ALU) are the parts of CPU.
13. CONTROL UNIT (CU)
The Control Unit acts like a traffic police. Its main function is to control and
co-ordinates the flow of instructions and data between all the other parts of
CPU. It is a sort of manager of all operations that takes place within the
system.
14. ARITHMATIC LOGIC UNIT (ALU)
An Arithmetic Logic Unit (ALU) is a digital circuit used to perform arithmetic
and logic operations. It represents the fundamental building block of the
central processing unit (CPU) of a computer. Modern CPUs contain very
powerful and complex ALUs. In addition to ALUs, modern CPUs contain a
control unit (CU).