2. WHAT IS COMPUTER ?
• Computer is an electronic device that takes input, process it and gives
output. Examples are desktop computers, Laptop, Palmtop, Super computer,
embedded systems, etc.
computer works on 0 and 1
• There is no physical significance of 0 and 1 in computer system. 0 and 1 are
just representation of two states of voltage levels in digital circuits. If there is a
supply of high volt in the circuit it is termed as 1 and for low volt it is 0. These
encoding help us to handle any sort of information through digital circuits.
3. WHAT IS HARDWARE ?
• Hardware is a comprehensive term for all of the physical parts of a computer,
as distinguished from the data it contains or operates on, and the software
that provides instructions for the hardware to accomplish tasks.
4. WHAT IS AN OPERATING SYSTEM ?
• Operating system is essential software which provides an interface between
user and machine. It acts as a manager in the system, which manages
hardware and software resources. It also does process management, memory
management and file management.
• Examples of Operating systems are windows XP, Windows 2007, Windows 8
Linux, Mac etc.
5. WHAT IS FILE ?
• A computer file is a data bundle created by a program used to refer back to
saved work or support the operating of the program.
• Files are of different types, which mean information is encoded in a particular
manner. Each such manner is a separate file format. Notice files stored in your
computer’s memory disk, each has some name for identification followed by
file extension. File name and extension are separated by a dot operator. File
extension tells about type of the file. For example track1.mp3 is a file with
extension mp3 which means it is an audio file.
• Among the several file formats, we are concern about a special file format
with extension exe.
6. BASIC COMPUTER ARCHITECTURE ?
• It is important to describe the role of few of the hardware resources during
execution of program. Earlier we talked about an executable file. Here we
are describing execution process of any one of such exe file.
• Firstly, your program (sum.exe) file is stored somewhere in hard disk of your
system. Now we clicked on it to run this program. This click event from mouse
is listened by operating system and loads this file from hard disk to RAM
(random access memory) using loader (a dedicated program to load
content to RAM). Here it is important to note that each time when some
program need to be activate, program must load in to RAM. RAM is also
known as primary memory which is volatile in nature that is nothing can
reside permanently. RAM contains only those programs that are active at
particular instant.
7. • Operating system allocates memory for our program in RAM. First instruction
goes to the processor and resides in instruction register. This instruction is
decoded by control unit. Control unit sends appropriate signal to ALU. ALU
performs specific task. Registers, control unit and Arithmetic Logic Unit are
part of processor. ALU is responsible to perform all kind of arithmetic, logical
and shift instructions. Again next instruction moves to processor and stored at
instruction register, control unit decode it and sends a signal to ALU. Every
instruction of the program executes in similar fashion in a sequential manner.
• As soon as the last instruction is executed memory of the program will released
from RAM.