Computer Fundamentals

This page contains the CBSE class 11 Computer Science with Python chapter 1, Computer Fundamentals . You can find the questions/answers/solutions for the chapter 1 of Unit 1 of CBSE class 11 Computer Science with Python in this page.

Computer Fundamentals
a. Name at least four early calculating devices.
The following are few of the early calculating devices
i. Abacus (3000 BC)
ii. Napier’s logs and bones (1617)
iii. Pascaline (1642)
iii. Leibnitz’s calculator (1673)
vi. Jacquard’s loom (1801)
b. Name the first operational general purpose computer.
The first operational general purpose computer Mark 1 was constructed in 1944 by Professor Howard Aiken. He did this in collaboration with IBM. He developed it based on the concept of Charles Babbage’s analytical engine.
c. Who first proposed the concept of Stored Program Computer?
Dr. John Von Neumann was the first person who proposed the concept of Stored program computer. He did this in the year 1945. In his proposition, he suggested that the same memory unit can be used to store both the program and the data

d. Define the IPO cycle.
The most basic functions of a computer are to take input through the input input, process it using the CPU and produce an output through the output units. This process can be represented with the help of the Input – Process – Output cycle (IPO cycle). Every task hendled by the computer follows this cycle. The working of this cycle can be stated as follows:
i. Input is supplied through the input peripherals
ii. The supplied input is read and is then processed by the CPU
iii. The processed data is then output through the output devices
e. Differentiate between data and information.
The following are the differences between the data and the information.
Data
Information
Simplest or most raw form of facts and figures.
Processed data with a significant and meaningful form.
Unorganized representation
Organized representation of data
Obtained through observation
Obtained through analysis
Does not make sense before processing.
Obtained through analysis and processing the data and hence makes sense.
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f. Explain the Von Neumann Computer.
The following is the architecture of Von Neumann computer.
 
Program
+
Data
 
Communication
Channel
Processor
Storage (Memory)
The Von Neumann computer was based on the concept of storing both the program and data in the same memory unit. As per this computer architecture, the processor fetches the instructions from the memory unit and executes. This implies that there will be only one communication channel. However, this led to a limitation, known as the Von Neumann bottleneck, where in only either data or instruction can be fetched from the memory in a sequential manner. The first computer based on this architecture was developed in 1952 and was called as EDVAC (Electronic Descrete Variable Automatic Computer).

g. Compare the salient features of first and second generation computers.
First Generation Computers
Second Generation Computers
1. Vacuum tubes were used for controlling and amplifying the electronic signals.
1. Used transistor transistors as underlying technology.
2. Huge in size
2. Comparatively smaller in size
3. Occupied lot of space
3. Occupied relatively lesser space
4. Electiricity consumption was high
4. Electricity consumption was low
5. Generated lot of heat
5. Generated less heat
6. More failures and hence less reliable
6. Comparatively more reliable.
7. Expensive
7. Relatively less expensive.
8. Continuous maintenance was required.
8. Maintenance requirement was relatively less frequent.
9. Needed continuous air conditioning.
9. They also needed continous air conditioning.
10. No operating system.
10. Run on operating system.
11. Used machine languages initially.
11. Used assembly language initially.
12. Used assembly languages towards the end.
12. Used high lvel languages at a later stage.
13. Commercial production was not viable.
13. Commercial production was not viable.
14. Not commercialized.
14. Were commercialized.
15. Used magnetic core for primary memory.
15. Used magnetic core as the primary memory.
16. Used magnetic drum and magnetic tape for secondary memory.
16. Magnetic discs were used for secondary memory.

h. Why is Charles Babbage known as the Father of Modern Computers?
Charles Babbage was an English mathematician. In 1822, he invented a machine known as the Difference Engine. This machine cwas cabale of calculating different mathematical functions. It was also capable of performing polynomial evaluations by finite difference. Theoretically (it was not practical at that time) it was also cable of solving differential equations.
In 1833, he designed another engine known as Analytical Engine. This design later became the basis of modern computers. It was capable of performing the basic four arithmetic operations (addition, subtraction, multiplication and division) and was also able to do the comparison operations. As per the concept, it contains input device, central processor, memory storage and output device. It was even possible to make changes to the stored information. However analytical engine was not implemented practically during his time. However, he proposed the basic principles on which the modern computers work.
Due to these great and revolutionary inventions, Charles Babbage was honoured with the title Father of Modern Computers.

i. Explain the functional components of a computer with the help of a block diagram.
The following is the block diagram of the functional components of the computer.
 
Memory
Unit
CPU
↑  ↓
ALU
Registers

CU

Input
Unit
Output
Unit
1. Input Unit: It consists of the various input peripherals such as keyboard, joystick, mic, mouse, scanner, camera etc. After reading the input, these devices convert the input to binary language. The binary language is well understood by the computer so it can understand the input that is being fed to it.
2. Central Processing Unit (CPU): CPU is mounted on a small chip. Due to this it is also called as the micro processor. CPU controls the centre of the computer and hence is called as the brain of the computer. The CPU’s main function is to process the input read from the input devices. It reads the instructions from the memory. It then interprets these instructions to understand what needs to be done and then executes them. Any additional data required to execute these instructions is read either from the input devices or from the memory. CPU has three components which perform different functions –
a. Arithmetic and logic unit (ALU): – As the name implies, this unit performs

i. Arithmetic Unit performs the arithmetic/mathematical calculations i.e. addition, subtraction, multiplication and division.
ii. Logical unit takes logical decisions which involve comparison of two data items and find whether one is larger than the other or smaller than the other or both are equal.

b. Control unit: As the name implies, the control unit controls and coordinates the data flowing into and out of the CPU. It also controls all the operations of ALU (Arithmetic and Logical Unit), memory registers and input/output units. The control unit executes all the instructions stored in the program. It first decodes the read instructions, interpretes them and then transfers the control signals to the input/output devices. It does this till the required operation is completed properly by the ALU and memory.
c. Memory registers: Registers are temporary units of CPU’s memory. They are used to temporarily store the data/instructions sent to them. Registers can be of different sizes like 16 bit, 32 bit, 64 bit etc. These registers have specific functions like like storing the data/instruction/address of a location in the memory etc. Programs written in assembly language can directly use the registers to store operand, intermediate results etc. The man register in the CPU is the Accumulator (ACC). ACC stores one of the operands of an operation to be performed in ALU.
3. Memory: This is attached to the CPU and is called as internal memory or primary memory or main memory. It is used to store data and instructions. It holds the data while processing. It is divided into many storage locations of equal size. Each location has an address and can store data or instructions. Using this address, the computer can find the data easily without searching all the memory. While executing a task, CPU uses the memory for storing the data and instructions. Once the task is completed this memory is freed up and is made available for the execution of the subsequent task. The time to access the data is same fro all the locations in the memory and does not vary. So, this memory is also called Random Access Memory (RAM). As this memory is volatile, the data stored in this memory is cleared when the power is switch off and can not be recovered. So, we can not use this for storing the data permanently and we use the secondary memory like hard disk, SSD, compact disc, pen drive etc for storing the data to use it afterwards.
4. Output Unit: Output unit has the output devises like monitor, projector, audio speakers, printer, plotter etc attached to the computer. This unit is responsible for converting binary data from the CPU to human understandable form.

j. What are the functions of the control unit?
The control unit is one of the three components of the CPU. Its functions are as follows –
– It controls and coordinates the data flowing into and out of the CPU
– It also controls all the operations of ALU (Arithmetic and Logical Unit), memory registers and input/output units.
– It first decodes the read instructions, interpretes them and then transfers the control signals to the input/output devices.
– It does this till the required operation is completed properly by the ALU and memory.
k. Where are the instructions needed to start a computer stored?
The instructions needed to start a computer are stored in the ROM. This action triggers the booting of the computer.

l. Explain booting process and its types.
Booting is the process that starts when the power button of the computer is switched on. The boot program resides in the ROM. When booting starts, a copy of the boot program is read into the main memory. Then the following steps take place in sequence. To start with, the CPU runs an instruction (at location FFFF0H) in the memory of BIOS. This location contains the jump start instruction . This jump start instruction helps the processor to know where to find the real BIOS program and then it starts executing it. The BIOS then performs a series of self diagnostic tests. These tests are referred to as POST and include the following
i. Memory tests
ii. Configuring and starting video circuitry tests
iii. Configuring system hardware
iv. Checking other devices that are needed for the proper functioning of the computer
Once these tests are completed, the BIOS locates the bootable drive and loads the boot sector. From here on the Bootstrap Loader program on the boot sector starts. This program loads and executes the operating system. In cases where in the boot sector is located on the hard drive, there will be a Master Boot Record(abbrevated as MBR) that checks the partition table for active partition. If the active partition is available, MBR loads boot sector located on that partition and starts executing it.
Booting process can take place in any of the two ways specified below:
1. Cold Booting: The cold booting, also known as hard booting, occurs when the computer is switch on from the off state it starts from the initial state. As soon as the power button is pressed, the booting process is initialized starting with reading the instructions from ROM
2. Warm Booting: Warm booting, also known as soft booting, takes places when the system is restarted or when the reset button is pressed. As the system is not starting from the inital state, it will not perform all the diagnostic tests. Warm booting is likely to caus data loss or system damage as the data might not have been stored properly.

m. Differentiate between :

a) Digital computers and analog computers.
b) Microcomputers and Mini Computers

The following are the differences between digital and analog computers.
Digital Computers
Analog Computers
Can process information indiscrete form.
Can process continuous data with changeable aspects of physical phenomenon.
Operates mainly on data which can be in form of letters, symbols or numbers and can be converted to binary form.
Operates on data generated by changes in continuous physical quantities.
High accuracy
Comparatively less accurate.
Its processes mainly consist of counting and adding operations.
It operates on data obtained from changing physical quantities, mainly when the change in response is fast.
Suitable for Processing large amounts of data
Suitable for conducting repeated experiments in real time environment and for stimulating systems.
Used in industrial, business and scientific fields
Used for simulating aircrafts, nuclear power plants, hydraulic and electronic systems
The following are the differences between micro computers and mini computers.
Micro Computers
Mini Computers
They work on small amounts of data
They are used to support multiple users to work on a common platform simultaneously.
Used individually for personal/business use in the form of desktop/laptop/tablet/PDAs
Used in small businesses to interconnect various departments.
Generally small and portable
Comparatively larger in size, in general.
High speed
Comparatively slower.
They work on small amounts of data, versatile and handle variety of applications.
They’re used for business computing like process control and performing adminstrative and financial operations of a business.
They became very popular and are widely being used.
They’re no more popular..