Unit-I: Introduction to Computer and Problem-Solving Methodology
Computer System, Computing Environments, Software, Types of Software and Features of
Software.
Design Tools (Algorithm, Flow-Chart, Pseudo-Code). Types and Generations of Programming
Languages. Compiler, Interpreter, Linker, Loader, Execution of Program. Develop an Algorithm
for Simple Problems.
Computer System
A computer is an electronic device that can be programmed to accept data (input), process it and
generate result (output). A computer along with additional hardware and software together is called
a computer system. A computer system primarily comprises a central processing unit (CPU),
memory, input/output devices and storage devices. All these components function together as a
single unit to deliver the desired output. A computer system comes in various forms and sizes. It
can vary from a high-end server to personal desktop, laptop, tablet computer, or a smartphone.
Figure 1.1 shows the block diagram of a computer system. The directed lines represent the
flow of data and signal between the components.
1.1.1 Central Processing Unit (CPU)
It is the electronic circuitry of a computer that carries out the actual processing and usually referred
as the brain of the computer. It is commonly called processor also. Physically, a CPU can be placed
on one or more microchips called integrated circuits (IC). The ICs comprise semiconductor
materials.
The CPU is given instructions and data through programs. The CPU then fetches the program and
data from the memory and performs arithmetic and logic operations as per the given instructions
and stores the result back to memory. While processing, the CPU stores the data as well as
instructions in its local memory called registers. Registers are part of the CPU chip and they are
, limited in size and number. Different registers are used for storing data, instructions or
intermediate results. Other than the registers, the CPU has two main components — Arithmetic
Logic Unit (ALU) and Control Unit (CU). ALU performs all the arithmetic and logic operations
that need to be done as per the instruction in a program. CU controls sequential instruction
execution interprets instructions and guides data flow through the computer’s memory, ALU and
input or output devices. CPU is also popularly known as microprocessor.
1.1.2 Input Devices
The devices through which control signals are sent to a computer are termed as input devices.
These devices convert the input data into a digital form that is acceptable by the computer system.
Some examples of input devices include keyboard, mouse, scanner, touch screen, etc., Besides, we
can now enter data through voice, for example, we can use Google voice search to search the web
where we can input the search string through our voice. Data entered through input device is
temporarily stored in the main memory (also called RAM) of the computer system. For permanent
storage and future use, the data as well as instructions are stored permanently in additional storage
locations called secondary memory.
1.1.3 Output Devices
The device that receives data from a computer system for display, physical production, etc., is
called output device. It converts digital information into human understandable form. For example,
monitor projector, headphone, speaker, printer, etc.
Software
Software is a set of programs, which is designed to perform a well-defined function. A program is
a sequence of instructions written to solve a particular problem.
Till now, we have studied about the physical components or the hardware of the computer system.
But the hardware is of no use on its own. Hardware needs to be operated by a set of instructions.
These sets of instructions are referred to as software. It is that component of a computer system,
which we cannot touch or view physically. It comprises the instructions and data to be processed
using the computer hardware. The computer software and hardware complete any task together.
The software comprises a set of instructions which on execution deliver the desired outcome. In
other words, each software is written for some computational purpose. Some examples of software
include operating systems like Ubuntu or Windows 7/10, word processing tool like LibreOffice or
Microsoft Word, video player like VLC Player, photo editors like GIMP and LibreOffice draw. A
document or image stored on the hard disk or pen drive is referred to as a soft-copy. Once printed,
the document or an image is called a hard-copy.
Computer System, Computing Environments, Software, Types of Software and Features of
Software.
Design Tools (Algorithm, Flow-Chart, Pseudo-Code). Types and Generations of Programming
Languages. Compiler, Interpreter, Linker, Loader, Execution of Program. Develop an Algorithm
for Simple Problems.
Computer System
A computer is an electronic device that can be programmed to accept data (input), process it and
generate result (output). A computer along with additional hardware and software together is called
a computer system. A computer system primarily comprises a central processing unit (CPU),
memory, input/output devices and storage devices. All these components function together as a
single unit to deliver the desired output. A computer system comes in various forms and sizes. It
can vary from a high-end server to personal desktop, laptop, tablet computer, or a smartphone.
Figure 1.1 shows the block diagram of a computer system. The directed lines represent the
flow of data and signal between the components.
1.1.1 Central Processing Unit (CPU)
It is the electronic circuitry of a computer that carries out the actual processing and usually referred
as the brain of the computer. It is commonly called processor also. Physically, a CPU can be placed
on one or more microchips called integrated circuits (IC). The ICs comprise semiconductor
materials.
The CPU is given instructions and data through programs. The CPU then fetches the program and
data from the memory and performs arithmetic and logic operations as per the given instructions
and stores the result back to memory. While processing, the CPU stores the data as well as
instructions in its local memory called registers. Registers are part of the CPU chip and they are
, limited in size and number. Different registers are used for storing data, instructions or
intermediate results. Other than the registers, the CPU has two main components — Arithmetic
Logic Unit (ALU) and Control Unit (CU). ALU performs all the arithmetic and logic operations
that need to be done as per the instruction in a program. CU controls sequential instruction
execution interprets instructions and guides data flow through the computer’s memory, ALU and
input or output devices. CPU is also popularly known as microprocessor.
1.1.2 Input Devices
The devices through which control signals are sent to a computer are termed as input devices.
These devices convert the input data into a digital form that is acceptable by the computer system.
Some examples of input devices include keyboard, mouse, scanner, touch screen, etc., Besides, we
can now enter data through voice, for example, we can use Google voice search to search the web
where we can input the search string through our voice. Data entered through input device is
temporarily stored in the main memory (also called RAM) of the computer system. For permanent
storage and future use, the data as well as instructions are stored permanently in additional storage
locations called secondary memory.
1.1.3 Output Devices
The device that receives data from a computer system for display, physical production, etc., is
called output device. It converts digital information into human understandable form. For example,
monitor projector, headphone, speaker, printer, etc.
Software
Software is a set of programs, which is designed to perform a well-defined function. A program is
a sequence of instructions written to solve a particular problem.
Till now, we have studied about the physical components or the hardware of the computer system.
But the hardware is of no use on its own. Hardware needs to be operated by a set of instructions.
These sets of instructions are referred to as software. It is that component of a computer system,
which we cannot touch or view physically. It comprises the instructions and data to be processed
using the computer hardware. The computer software and hardware complete any task together.
The software comprises a set of instructions which on execution deliver the desired outcome. In
other words, each software is written for some computational purpose. Some examples of software
include operating systems like Ubuntu or Windows 7/10, word processing tool like LibreOffice or
Microsoft Word, video player like VLC Player, photo editors like GIMP and LibreOffice draw. A
document or image stored on the hard disk or pen drive is referred to as a soft-copy. Once printed,
the document or an image is called a hard-copy.
