The document provides information on the typical configuration of a computer system. It discusses the main components of a computer system including the input unit, central processing unit, storage unit, and output unit. It then describes the motherboard in more detail. The motherboard contains the processor, BIOS, CMOS, slots for expansion cards, disk controllers, I/O ports, and buses that connect the components. The document outlines the characteristics, components, and functions of the motherboard and its role in connecting the various parts of a computer system.

1. Typical Configuration of
Computer System

2. Introduction
• “Computer is an electronic machine that can
store, recall and process data. It can perform
tasks or complex calculation according to a
set of instructions or programs”
• Computers are used to perform various tasks
in different fields like science ,engineering,
business education training entertainment.
• The computer works at high speed can
handle large volume of data with greater
accuracy.

3. The terms and definitions in the study of
computer system are:
• Hardware: The physical parts of a computer
system called as hardware. The hardware
components can be seen, touch and feel.
Ex: Keyboard, Mouse, Monitor, RAM, CPU
etc.
• Software: A Set or collection of programs is
known as software.
Example Operating System

4. Cont..
• Data: Data is the raw information or basic
facts that computer can process.
• Information : Information is a processed
data
• User(s): People who use the computers are
called users.

5. Block diagram of a computer:
The computer system comprises of 4 main units
which can be seen in the block diagram,
1. Input unit
2. Central Processing Unit
2.1 Control unit
2.2 Arithmetic and logical unit
2.3 Registers
3. Storage unit
4. Output unit

7. 1. Input unit : The user interact with the
computer via the input unit. Computers need
to receive data and instructions in order to
solve a problem. The Input unit performs this
operation. The input data can be character,
word,text,sound etc. The input is provided to
the computer using input devices like
keyboard,mouse,joystick,scanner,microphon
e etc.

8. 2. Central Processing Unit: CPU controls
coordinates and supervises the operations of
the computer. It is also responsible for
processing of the input data.
⮚It consists of two major units,
1. ALU
2. CU
⮚ CPU also have set of registers for temporary
storage of data, instructions address and
intermediate result of the calculation.

9. • ALU( Arithmetic and Logical Unit) : Performs
all arithmetic and logic operations on the
input data
• CU(Control Unit) : Controls the overall
operations of the computer.
eg: it checks the sequence of execution of
instruction controls and coordinated the
overall functioning of the computer.

10. • Registers : It is high speed storage units
within the CPU ,but have least storage
capacity. (Registers are not referenced by
their address but are directly accessed by
the CPU during the execution

11. 3. Storage Unit : The results generated from
processing have to be preserved before it is
displayed.
There are 2 types of memory associated with
the storage unit they are Primary memory and
Secondary memory.
• Primary memory : It is the main memory of
the computer, consists of RAM(Random
Access Memory) and ROM(Read Only
Memory)

12. • Main memory stores data ,information
temporarily during the processing of data.
• The secondary memory also called as
external memory of the computer that
stores data permanently.
• Eg : Magnetic disk, magnetic tapes,
Pendrive, CD’s etc.

13. 4. Output Unit: It is used to print or display
the results after processing of data, which
are stored in the memory unit.
The computer may display the output
on a monitor sends the output to the
printer and also send sound output to the
speaker.

14. Motherboard
• The motherboard is a large Printed Circuit
Board (PCB), called as main circuit board of
the computer, which contains many chips,
ports, controllers and other electronic
components.

15. Introduction to Motherboard
• Motherboard is the main circuit board inside
the computer. Every components inside the
computer has to communicate through the
motherboard.
• The motherboard is a hub which is used to
connect all the necessary components of a
computer.

16. Characteristics of motherboard
• The motherboard is characterized by the
form factor, chipset and type of processor
socket used.
⮚Form factor : refers to the motherboard’s
geometry, dimensions, arrangement and
electrical requirements.
⮚Chipset : controls the majority of resources
of the computer. The function of chipset is
to coordinate data transfer between the
various components of the computer.

17. Cont..
⮚ processor socket :The processor socket
may be a rectangular connector into which
the processor is mounted vertically, or a
square shaped connector with many small
connectors into which the processor is
directly inserted.

18. Types of motherboard
• There are four different types in
motherboard depending on the
processors used they are XT, AT, Baby AT
and ATX.

19. 1. XT Motherboards:
• XT stands for Extended Technology.
• These are old model motherboards.
• In this we find old model processor socket
like LIF(Low Insertion Force) sockets, RAM
slots: DIMM (Dual Inline Memory Modules)
and ISA(Industry Standards Architecture)
slots, 12 pin power connector. They have slot
type processors and no ports.
• Ex: Pentium-I, Pentium-MMX, Pentium-II and
Pentium-Pro.

20. XT motherboard

21. 2. AT Motherboards:
• AT stands for Advanced Technology.
• AT Motherboards have PGA (Pin Grid Array)
socket, SD RAM slots, 20 pin power
connector, PCI slots and ISA slots.
• Ex: Pentium-III Processors.

22. AT motherboard

23. 3. Baby AT Motherboards:
• Baby AT motherboards have the
combination of XT and AT.
• They have slot type processor socket and
PGA processor socket SDRAM slots and
DDRRAM slots, 20 pin power connector and
12 pin power connector.
• Ex: Pentium-III and Pentium-IV

24. Baby AT motherboard

25. 4. ATX Motherboards:
• ATX motherboard stands for Advanced
Technology eXtended Motherboard
• Latest Motherboard all are called as ATX
motherboard, designed by ATX form factor.
• In this motherboard, MPGA Processor
sockets, DDRRAM Slots, AGP Slots, 20 pin
and 24 pin ATX power connector and ports.

26. ATX motherboard

27. Components of Motherboard
• The motherboard components are:
1. Processor(CPU)
2. BIOS
3. CMOS
4. Slots
5. Disk Controller
6. I/O ports and Interfaces
7. BUS

28. Processors (CPU):
• The processors or CPU is the main
component on the motherboard and is
called the brain of the computer
• CPU consists of 1) ALU 2) CU 3) Registers
• Arithmetic and logic unit performs all the
arithmetic and logic operations on data.
• CU is responsible for organizing the
processing of data and instructions.
• Registers is a temporary storage areas for
holding data and instructions

29. Processor socket

30. Note:
• Clock Speed: A measure of a processor’s
operating speed, currently measured in MHz
(Megahertz) and GHz (Gigahertz).
• A CPU’s performance is measured by the
number of instructions executed per second
i.e. MIPS & BIPS
• Microprocessor: It is an electronic
component. It is a single integrated circuit (IC)
Chip. This tiny chip contains the entire
computation engine. Example: Intel

31. BIOS (Basic Input Output System)
• BIOS is a small chip on the motherboard
that holds a set of instructions to load the
hardware settings required like keyboard,
monitors or disk drives.
• The BIOS runs when the computer is
switched ON.

32. BIOS

33. Cont..
• It performs POST ( Power On Self Test), It
checks if the hardware devices are present
and functioning properly.
• BIOS include the bootstrap loader to load
the OS into memory

34. CMOS (Complementary Metal Oxide
Semiconductor)
• It is a type of memory chip to store date,
time and system setup parameters.
• These parameters are loaded every time
the computer is started.
• BIOS & CMOS are kept powered by a small
lithium Ion battery located on
motherboard.

35. CMOS

36. Slots
• Slot: A slot is an opening space in a computer
where we can insert a printed circuit board.
• Slots are often called expansion slots.
• There are several types of slots are:
1. ISA (Industry Standard Architecture)
2. PCI (Peripheral Component Interconnect)
3. AGP (Accelerated Graphic Port)
4. RAM Slot
5. Processor Slot

37. ISA (Industry Standard Architecture)
slots
• ISA slot is used in PCs for adding expansion
cards. For example, an ISA slot may
be used to add a video card, a network card
etc.

38. ISA slots

39. PCI(Peripheral Component
Interconnect)slots
• PCI slots are used to connect graphics
accelerators cards, sound card, internal
modems
• They are much faster than ISA cards.
• PCI has double bit-width, resulting
in faster data transfer than ISA

40. PCI slots

41. AGP (Accelerated Graphic Port)
• It provides faster access to connect
graphics accelerator card, thus enhancing
the visual experience for the user
• All Pentium III motherboards comes with
AGP slots

42. AGP slots

43. RAM slot
• RAM slot is used to install memory to store
programs and data currently being used by
CPU.
• RAM is measured in units called bytes.
• Two types of RAM slot
1. SIMM (Single Inline Memory Module)
2. DIMM ( Dual Inline Memory Module

44. RAM slot

45. Processor Slot
• Processor slot is used to insert the
processor chip which is the largest chip on
the motherboard.

46. Processor fan or heat sink

47. Disk controller
• Disk controller is the circuit that enables
the CPU to communicate with a hard
disk, floppy disk or other kind of disk
drive.
1. Hard disk controller
2. Floppy disk controller

48. Hard disk controller
• The HDC is the interface that enables
the computer to read and write
information to the hard disk drive
• Today, hard drives have the controller
built on them

49. Floppy Disk Controller (FDC)
• FDC is the interface that directs and
controls reading from and writing to
computer floppy disk drive.
• The floppy disk controller usually
performs data transmission in direct
memory access (DMA) mode.

50. I/O Ports and Interfaces
• A port is a socket on the computer used
to connect external device to the
computer.
• Like printers, keyboards, scanners etc
• These ports and interfaces are found on
the rear side of the computer.

51. I/O ports

52. • The different types of I-O ports are
1. Serial port
2. Parallel port
3. USB port
4. AGP port etc

53. Serial port
• Serial Port, also known as communication port
or Rs-232 c ports
• It is used for connecting communication
devices like mouse and modem
• This port transfers data serially one bit at a
time.
• There are two varieties in serial ports, the 9
pin and 25 pin port

55. Parallel port
• Parallel ports are used to connect
external input/output devices like
printers or scanners.
• Also known as printer port
• They carry 8 bit (one byte) at a time

57. IDE (Integrated Digital Electronics)
port
• It connects IDE devices like CD-ROM
drives or hard disk drives to the
motherboard

58. IDE port IDE connector

59. USB port
• USB (Universal Serial BUS) port is used to
connect a variety of newer peripherals like
printers, scanners, digital cameras, web
cameras, speakers, etc. to a computer
• USB is a plug-and-play interface between a
computer and add-on devices such as audio
players, modem, scanner etc

60. • With USB, a new device can be added to
your computer without adding a adapter
card or even turning the computer off.
• USB supports a data speed of 12
megabits per second

61. USB port USB cable

62. PS-2 (Personal System) port
• PS-2 port was developed by IBM to
interface keyboards and pointing devices
like mouse, trackballs and touch pads.

64. AGP (Accelerated Graphics Port) port:
• It is used to connect to graphic card that
provides high-speed video performance
typically required in games and other
multimedia applications

65. Modem
• Modem (Modulator demodulator)
connects a PC to the telephone network.

66. Ethernet port
• Connects to a network and high speed
Internet.
• It connects network cable to a
computer.

67. MIDI
• MIDI (Musical Instrument Digital Interface)
port is a system designed to transmit
information between electronic musical
instruments.

68. BUS
• “A bus is a collection of parallel wires
that form a pathway to carry address,
data and control signal “
• The different components of the
computer are connected to each other
by a bus.
• The data, instructions, signals are carried
between the different components via
bus.

69. The functional features of bus are:
1. A bus is a set of wire and each wire can
carry one bit of data.
2. A bus width is defined by the number of
wires in the bus
Types of computer bus:
A computer bus can be divided into two
types
• Internal bus
• External bus

70. o Internal Bus:
1. It connects major computer components
like processor, memory & I/O.
2. It is also called as system bus.
o External Bus:
1. It connects the different external devices
peripheral, expansion slots, I/O ports to the
rest of the computer.
2. It is also called the expansion bus and is
slower than the system (internal) bus

71. A system bus or expansion bus comprise
of three kinds of buses;
1. Data bus:
• It provides a path to transfer data between
CPU and memory.
• The data bus may consists of 32, 64, 128 lines
of wire
• The number of lines referred as the width of
the data bus

72. 2. Address bus:
• It connects CPU & RAM with a set of lines
similar to data bus.
• The address bus width determines the
maximum number of memory location the
computer can address
3. Control Bus:
• It is used to control the access to and the use
of the data and address lines

73. System bus structure

74. Memory
• A computer memory refers to the
electronic storing space for instructions
and data.
• Two kinds of memory are commonly
used:
1. Internal memory
2. Secondary Memory

75. Internal memory
• Internal memory includes registers, cache
memory and also primary memory
• Which can be directly accessed by CPU’s
processor.
• It is used for temporary storage of data and
instructions.
• This memory is very expensive and fastest
among all other memory.

76. Features of Internal memory
1. Temporary storage
2. Limited storage capacity
3. Fast access
4. High cost

77. Registers
• The registers are high speed temporary
storage areas located inside the CPU.
• After the CPU gets the data and instructions
from the cache, they are moved to registers
for processing.
• These registers are works under the direction
of Control Unit.