2. STORAGE DEVICES
One of the widely used Hardware for
Storing Permanent Data is HARD
DISK DRIVE
It is used for Storing of DATA for long
term use.
3. Hard Disk Drive
Introduction
Hard Disk Drive is a
nonvolatile data
storage device, it
means that the
storage device retains
the data even when
no power is supplied
to the computer.
Some of the profound
changes in PC hard
disk storage are its
capacity, data transfer
rates from the media.
4. Topic 4 - Hard drive Interface
Integrated Drive Electronics (IDE)/EIDE
It is used to attach Mass Storage media devices to
the computer.
The next generations of IDE interface is Enhanced
IDE (EIDE)
Small Computer System Interface (SCSI)
It is capable of supporting up to 7 to 15 devices.
Serial ATA (SATA)
It is an internal or inside-the-box interface technology.
External SATA is commonly known as ESATA.
USB
It is an External , pocket Harddisk
5. Topic 1 - Features
Storage Capacity
The storage capacity of the hard disk refers to the amount of
disk space that can be used to store the user data.
Data Transfer Speed
There are two ways to measure the speed of the disk drive
Average seek time
Transfer rate
Stability
It has been measured by Mean Time Between Failure (MTBF).
8. IDE HARD DISK DRIVE
IDE Hard Disk is a 40 Pin Connector
Hard Disk and is Connected to IDE
connector on Motherboard
9. Motherboard Connections
Primary IDE controller is
usually faster – ATA/66, 100
or 133. Secondary controller
operates at ATA/33
Normally, the IDE controllers
Identified as IDE1 and IDE2
on the motherboard
Onboard Controllers
(2 x 40 pin male ports)
12. Topic 3 - Hard Disk Drive
Components
A flat, round disk called platters
is used in a hard disk
The platters are loaded on a
spindle.
Spindle motor spins the platters.
Electromagnetic read/write
devices called heads are mounted
onto sliders.
Each platter has two heads
13. Topic 3 - Hard Disk Drive
Components
Platters
This platter is made up of substrate material, which gives
structure and rigidity
Platters are physically connected in the middle and driven by
the spindle motor.
Hard Disk Read/Write Heads
The hard disk drive read/write heads act like an interface
between the magnetic media and the part of the hard disk.
Heads are joined to the head actuator move across the disk.
14. Topic 3 - Hard Disk Drive
Components
Types of Read or Write Heads
Ferrite Head – It is used for magnetic recording.
Metal in Gap Head (MIG) - A metal substance has been
filled in the gap, and increases the resistance of magnetic
saturation.
Thin Film Head - This head floats closer to the disk than
the other heads.
Magneto Resistive Head - The MR head can change
resistance.
15. Topic 3 - Hard Disk Drive
Components
Giant Magneto Resistive
Head (GMR) - It will work
on multilayer of materials
dumped in it.
Head Actuator
Mechanism
Stepper motor actuators
It is an electrical motor
that can step from location
to other, with click-stop
positions
Voice Coil Actuator
It is used to shift the head
arms in and out .
It has a special guidance
system
16. Topic 3 - Hard Disk Drive
Components
Spindle Assemble
Spindle Motor
The spindle motors are directly connected to the hard disk platter
spindle
The motor that spins the platters is called the spindle motor.
Logic Board (s)
The logic boards have electronics that control the drive’s spindle and
head actuator systems.
17. PLATTER
PLATTER IS A METALIC PLATE WHICH
IS USED TO STORE THE DATA IN THE
ELECTROMAGNETIC FORM.
THE
DATA
IS
SAVED
IN
TRACK,SECTOR & CLUSTER FORMAT
THERE CAN BE MORE THAN ONE
PLATTER IN A HARD DISK
18. SPINDLE MOTOR
SPINDLE MOTOR is used to revolve
the Platter to access the each and
every part of the HARD DISK
The revolving of the platter is
measured in RPM (RPM stands for
REVOLUTION PER MIN/ROTATIONS
PER MIN)
Current RPM ranges from 7,200 to
15,000
19. ACTUATOR
ACTUATOR is used to make access
the Read Write Head to the every
corner of the Platter
If we consider the live example for
the Actuator, it is like a CAR WIPER
which
moves
in
45
degree
approximately
20. READ AND WRITE HEAD
Read Write Head often refereed as
R/WHEAD
It is a Small Black Device which is
responsible for the Operation of
Reading and Writing.
It is used for Reading and Writing
operations from the HARD DISK
21. READ AND WRITE PROCESS
Platters are divided into 512 byte
sectors. These sectors are the area
on the platter that data is written to.
The platters have a magnetic coating
applied to them that is extremely
sensitive to magnetism.
22. LOGIC BOARD
IT is a Circuit Board which is used to
send
the
signals
and
logical
operations related to HARD DISK
23. WORKING
While the platters are rotating in a circle, the
read/write heads are moved over the disk
surface to the location where they need to
write (or save) information. The read/write
heads do not actually touch the surface of the
disk platters; instead, they “hover” about ten
micro-inches (or millionths of an inch) above
—that’s not even enough space to place a hair
between the read/write head and the platter’s
surface. This design helps improve disk
performance, because a read/write head that
made contact with the platter would cause
friction, slowing down the rotation speed of
the disk.
24. Hard Drive Controller
The controller allows
the hard drive to
send/receive data
using the external
data bus
Hard Drive
Controller
In IDE hard drives,
the contoller circuitry
is built into the drive
External Data Bus
26. TRACKS
Just as there are grooves, or tracks,
on a record or music CD, there are
also tracks on each platter. These
tracks are evenly spaced across the
platter’s surface.
27. SECTORS
The platter is divided into pie slices,
thus dividing the tracks into 512-byte
sectors. Sectors are the actual
storage areas for data, and each has
an address that is made up of the
platter side number, the track
number, and the sector number on
that track.
29. CLUSTERS
A group of any number of sectors can
make up a cluster. When a partition
is formatted, the file system will
determine the cluster size based off
the partition size. For example, a
partition that is 2GB in size formatted
as FAT will use a 32K-cluster size.
That same 2GB partition formatted as
FAT32 will use only a 4K-cluster size.
30. Topic 2 - Geometry of Hard
Drive
Cylinders
It is a set of all platters.
Heads
It is used to read data from the
hard disk drive’s disk platters
Sectors per Track
A track is a one ring of data on
single side
Tracks are divided into many
sectors.
Write pre-compensation
Used to adjust the smaller tracks
31. Topic 2 - Geometry of Hard
Drive
Landing-Zone
When the system is turned off, the BIOS should send the
heads of hard disk to the cylinder where there is no data.
Modes
Three methods available for data addressing
CHS (Cylinder Head Sector)
LBA (Logical Block Address)
ECHS (Extended Cylinder Head Sector)
43. Configuring a Hard Disk
1.
2.
3.
4.
5.
6.
7.
Connect data cable and power cable
Power up PC, enter BIOS
Standard CMOS settings
Auto detect or enter CHS values
Create partitions
Format each drive
Install O.S.
46. A+ Partition Facts
A maximum of 4 primary partitions per
disk
Up to 24 logical drives per disk
Each partition must be formatted
A PC must have at least 1 primary
partition
The primary partition is where the O.S.
is stored
Extra partitions are optional
48. Topic 9- File System
The file system decides the manner in which data is
accurately arranged on a hard disk drive.
The main function of the FAT is to give the mapping
between clusters and the physical location of data in
terms of cylinders, tracks, and sectors.
FAT 12
FAT 16
FAT 32
NTFS
49. Windows File Systems
File System is created when you
format the drive. The types are
FAT 16
FAT 32
NTFS
Formatting also creates the boot
record, the root directory, the File
Allocation Table and the data area
50. FAT 16
File Allocation Table 16-bit
A max of 216 = 65,536 addressable
sectors
Max partition capacity of 65,536 x 512 =
33Mb
Does not support disks larger than 2.1
Gb
Used up to Win95 release 1
1.44 Mb floppy disks, zip disks and USB
memory sticks are formatted using FAT
51. FAT 32
File Allocation Table 32 bit
A max of 232 = 4 billion addressable sectors
Grouped 4 512 byte sectors together = a
cluster
1 cluster = 2048 bytes or 2Kb
Max hard disk size = 2 Tb
Max partition size of (4 billion x 512 bytes)
= 32Gb
Allows for up to 24 logical drives
Windows 95 release 2 onwards
No mechanism for file security
52. NTFS
New Technology File System
64 bit file system
Windows NT, 2000, XP
Main Advantage = Security
(encryption)
Supports partition sizes up to 2048
Gb or 2Tb
53. Topic 5 - Data Organization in
Hard Disk
The data is recorded on the magnetic tracks of a
hard disk drive.
Each track is divided into number of sectors.
Data is pressed on each sector.
Microcomputers’ hard disk drives are following the
soft sector format.
In the latest soft sector format, the track number,
head number and sector number is written on
each sector’s ID field.
54. Topic 6 - Data Read and Write
Operation
Hard disk heads convert electrical signals to
magnetic signals and magnetic signals to electrical
signals.
By using encoding method, the stored data has
been recorded onto the hard disk.
This encoding method translates zeros and ones
into patterns of magnetic flux reversals.
55. Topic 7 - Hard Disk Drive
Configuration
Cable (Data and Power)
Power Cable
Interface Cable
Jumper Settings (Master/ Slave/ Cable Select)
They are sets of pins with caps placed in various
arrangements.
In some drives manufacturers have cryptic MS, SL, CS initials
BIOS settings
The BIOS made after 1996 will support a drive larger than
4GB.
56. Topic 7 - Hard Disk Drive
Configuration
IO Address
Devices use memory location for interfacing with the computer.
A typical hard disk controller uses 1F0-1F7h I/O port.
Interrupt Request Line (IRQ)
It permits a hardware device to look inside the computer.
When the device need attention, IRQ makes direct line to the
microprocessor
DMA Channel
Without CPU interference, the DMA controller transfers data
from a drive to the computer’s memory.
57. Topic 8 - Hard Disk Drive Setup
Low level formatting
The disk’s tracks are divided into a specific number of sectors.
LLF is most important for the proper operation of the drive.
Partitioning
The hard disk drive can support separate file systems by
creating a partition on a hard disk drive.
High level formatting
The operating system marks the structures essential for
managing files .
High-level formatting is the creation of a table of contents for
the disk
58. Topic 8 - Hard Disk Drive Setup
FDISK
For example: 4 gig hard drives, divided it into 4
partitions.
The four independent drives are ‘C’, ‘D’, ‘E’, and ‘F’.
'C' partition = 2 Giga Bytes
'D' partition = 1 Giga Bytes
'E' partition = 500MB
'F' partition = 500MB
59. Topic 10 - Sector Organization
Cluster
Grouping sectors into larger blocks are called
clusters .
Master Boot Record (MBR)
The location of the master boot record is cylinder
0, head 0, and sector 1.
DOS Boot Record (DBR)
In the beginning of the boot drive the DOS boot
record will load .
Boot Sector
The two tasks of boot sector is to load in the
operating system and to inform the user
information about the disk.
60. Topic 10 - Sector Organization
File Allocation Table
The FAT has entry for each cluster, which describes how
the file has been used, and which files are free for use.
Root Directory
FAT file system uses root directory to format disk.
Data Area
The content of the files are stored in data area.