Components of Computer system

1. TEXT BOOK:
David A. Patterson and John L. Hennessey,
“Computer organization and design’, Morgan
Kauffman / Elsevier, Fifth edition, 2014.

2. Computer System Components
Hardware Software
I/P O/P CPU MEM System App
Main Secondary General Special
Purpose Purpose

3. CPU
ALU Control Registers
Data Address Status General Program
Reg Reg Reg Reg Counter

4.  Mouse.
 Keyboard.
 Tracker Ball.
 Scanners.
 Touch Pads.
 Light Pens.
 Joy Sticks.

5.  VDU or Monitor.
 Printers.
 Plotters.
 Speakers.
 Speech synthesizers.

6.  Processing unit is the brain of any computer.
The functional units are
 Control Processing Unit (CPU)
 Arithmetic and Logical Unit (ALU)
 Control Unit
 Registers

7.  A Register is a small set of data holding place
which is a part of the computer processor.
Types:
 Data registers.
 Address registers.
 Status registers.
 Program Counter.
 General Purpose Registers.

8.  Main Memory (or)
Primary Memory.
Types
 RAM
 ROM
 Secondary Memory
Types
 Hard disk
 Floppy disk
 CD-ROM
 Magnetic disks
 Tape drive
 Flash Memory

9.  Bit :1 or 0 level of storage.
 Byte :Consists of eight bits.
 Kilobyte :Consists of 1024 bytes.
 Megabyte :Consists of 1024 kilobytes.
 Gigabyte :Consists of 1024 megabytes.

10.  s/w is a set of programs, which is designed
to perform a well defined function.
Types of Software
 System Software.
 Application Software.

11.  It is a collection of programs designed to operate,
and control the computer.
 The system software are prepared by computer
manufacturers.
Types:
 System Control Program.
 System Support Program.
 System Development Program.
Ex: Operating Systems, Utility Programs, and
Device drivers.

12. These software are specially designed to solve the
specific problems of users and is also known as
Software Package.
Types:
General purpose APP s/w ( Common needs)
Ex: MS Office, Web browser s/w etc.
Special purpose APP s/w (Specific needs)
Ex: Payroll software, Railway reservation etc.

13. Sl.no Year Technology used in Computer
1. 1951 Vaccum tube
2. 1965 Transistor
3. 1975 Integrated Circuit
4. 1995 Very large Scale Integrated Circuit
5. 2013 Ultra large Scale Integrated Circuit

14.  Technologies are used to improve the
performance of computer.
 The performance of the computer depends
on the Processor and the Memory.
 Technology shapes the computers as they
evolve.
 To update Technology the computer
professional should be familiar with the
basics of Integrated Circuits.

15. Transistor
A transistor is simply an on/off switch
controlled by electric signal.
Integrated Circuit(IC)
The IC combines dozens to hundreds of
transistors into a single chip.
Very Large scale Integrated Circuit(VLSI)
The VLSI combines thousands to millions
of transistors.

16.  Figure shows the growth
in DRAM capacity since
1977.
 For decades, the
industry has consistently
quadrupled capacity
every 3 years.
 Resulting in an increase
in excess of 16,000
times!

17.  Chip is the basic element for manufacturing IC.
 The manufacture of a chip begins with silicon.
 A substance found in sand.
 silicon does not conduct electricity.
 It is called a semiconductor.

18.  With a special chemical process, it is possible to
add materials to silicon that allow tiny areas to
transform into
one of three devices:
 Excellent conductors of electricity (using either
microscopic copper or aluminium wire)
 Excellent insulators from electricity (like plastic
sheathing or glass)
 Areas that can conduct or insulate under
special conditions (as a switch)

20.  Once good dies are found, they are connected
to the input/output pins of a package using a
process called bonding.
 These packaged parts are tested for a final
time.
 If there is no mistake it can be shipped to
customers.

21.  Metrics for measuring Performance
 Response Time (or) Execution Time.
 Throughput (or) Bandwidth.
 CPU Execution Time (or) CPU Time.
 User CPU Time and System CPU Time

22.  Response Time (or) Execution Time.
The time between the start and completion of
a task.
 Throughput (or) Bandwidth.
The total amount of work done in a given time.

23.  The computer that performs the same amount of
work in the least time is the fastest.
 Program execution time is measured in seconds
per program.
 CPU Execution Time (or) CPU Time.
The actual time the CPU spends computing
for a specific task.

24.  1. User CPU Time.
The CPU time spent in the program is called
the User CPU time.
 2. System CPU Time
The CPU time spent in the operating system
performing tasks on behalf of the program is
called System CPU time.

25.  All computers are constructed using a clock that
determines when events take place in the
hardware.
 Clock cycles are also called tick, clock period,
clock or cycle.
 The speed of a computer processor, or CPU, is
determined by the clock cycle.
Clock period
 The length of each clock cycle is known as clock
period.