3. What is a Computer?
An electronic device that stores, retrieves and
processes data, and can be programmed with
instructions.
A computer is composed of hardware and software, and can
exist in a variety of sizes and configurations.
4. Hardware & Software
The term hardware refers to the Physical
components of your computer such as the system
unit, mouse, keyboard, monitor etc.
The software is the instructions that makes the
computer work. Software is held either on your
computers hard disk, CD-ROM,DVD or on a diskette
(floppy disk) and is loaded (i.e. copied) from the disk
into the computers RAM (Random Access
Memory),as and when required.
5. Types of Computers
Mini and Mainframe Computers
Very powerful, used by large
organizations such an banks to control the
entire business operation. Very expensive!
Personal Computers
Cheap and easy to use. Often used as stand-
alone computers or in a network.
6. Processor
Processor is the brain of your computer
Some key concepts
Clock : In a computer, clock speed refers to the
number of pulses per second that sets the tempo for
the processor.
Cache :A small but fast memory area. Levels of cache exists.
32/64 bit processors: The amount of data a processor can
process in a clock cycle.
9. RAM
Random Access Memory.
When the operating system loads from disk when you first switch
on the computer, it is copied into RAM.
Types
Older Computers P4s DDR
Current Computers DDR2
New Computers DDR3
(Double Data Rate)
10.
11. ROM
Read Only Memory (ROM) as the name suggests is a special type of
memory chip that holds software that can be read but not written to.
A good example is the ROM-BIOS chip, which contains read only
software.
Often network cards and video cards also contain ROM
chips.
12. Motherboard
Themain circuit board which connects all
the device on a microcomputer; Also called
main board or system board.
16. Hard Disk
Stores data in magnetic disk like medium
Non-volatile mass storage device.
Has very high access time as compared to RAM
(10-20 million ns).
Very cheap as compared to RAM and so large in capacity.
Types
IDE- Integrated Drive Electronics
(or)
ATA - Advanced Technology Attachment
SATA- Serial Advanced Technology Attachment
19. Difference Between IDE & SATA
Interface transfer up to 8.3MB/s for ATA-2 and up to 100MB/s (ATA-6).
Transfer rates for Serial ATA begin at 150MB/s.
Big advantage of SATA over ATA is the cabling and
connectors in provides easier routing and better air flow .
Easier to install multiple SATA drivers where as in IDE it has an
jumper setting makes Some difficult tasks when more drives
connected at a time.
20. Cards
VGA Card
VGA –Video Graphics Adaptor
A modern graphics card is a circuit board with memory and a
dedicated processor.
Converts digital information into the pixels to display it on the
monitor.
21. Inbuilt VGA
On board graphics accelerators share system memory.
Resolution will be less when compare to external card.
22. Sound Card
Converts digital data (bits) into analog sound wave and
vice-versa
Has jacks for speaker, microphone, line in, line out and
joysticks
24. USB Card:
USB-Universal Serial Bus
To connect larger number of USB Ports to computers
25. Ports
Serial:
Serial port “serializes” data.
Monitors, Modems etc. use Serial port.
Parallel:
Bits transmitted in parallel.
Used primarily for Printers.
PS/2:
Used to interface keyboards and
pointing devices.
Frees the serial port for other devices.
26. USB
Data transfer rate 12Mbps/480Mbps.
Multiple devices supported on the bus
Hot pluggable, Plug-and-play.
Provide power through the cable.
28. BIOS
Basic Input Output System
Uses for boot up
Important Functions
Check CMOS Set-up.
POST - Power On Self Test.
Display system setting.
Initiate bootstrap sequence.
29. Configuring BIOS
System Time/Date.
Boot Sequence.
Plug and Play.
Drive Configuration.
Security.
Power Management
33. Modems
Internal Modem
Resides on the expansion board on the slot of the motherboard.
Does not require separate power adapter.
Cheaper than external modem.
Has natural protection inside PC cabinet
34. External Modem
Resides on a self-contained box outside the PC.
Requires external power adapter.
Connected to PC’s serial port via the cable.
Easy to install and troubleshoot such as resetting the modem.
Expensive than internal modems.
35. Cabinet
Types
AT Cases
ATX Cases
AT Cases
Older Motherboards (pre-pentium)
Advantages
Well Established standard make.
Easy and cheap design.
Disadvantages
Inefficient cooling.
Not suitable for P-II (& higher).
36. ATX Cases
Newer Motherboards (Pentium based machine)
Advantages
Efficient cooling.
Easy accessibility for upgrades.
I/O are fixed onboard.
38. Troubleshooting
• Some simple solutions
Check connections.
Ensure that cards are inserted properly.
Clean the devices.
Check if minimum things needed to boot are present –
motherboard, processor, a full bank of memory, video card and a
drive to boot.
39. The PC doesn’t start at all
Count the number of beeps.
No beeps - possible problem with BIOS or motherboard.
The PC starts - partially
No signal on the monitor.
Video signal present with error message.
OS starts.
OS does not start - Hard-disk problem.
40. Hard Drive
– Not bootable : A Hard Drive must be formatted and partitioned
before it can be used.
– Not detected by the BIOS - Check on a different m/c.
It works fine.
It does not work.