just learn and make presentation file

2. • What Is Storage Device
• History Of SCSI
• What is SCSI
• Internal SCSI
• External SCSI
• SCSI Host Adapter
• Types Of SCSI
• SCSI ID
• Daisy Chaining
• Termination
• Advantage Of SCSI
• Disadvantage Of SCSI

3. Storage Devices ?
• It can hold & store information both
temporarily & externally & can be internal or
external to a computer, server or any similar
computing device.

4. History of SCSI
SCSI is derived from “SASI” the shugart Associated system
interface “, developed circa 1978 and publicly disclosed in
1981. Larry Boucher is considered to be the “father“ of SCSI
and ultimately SCSI due to his pioneering work first at shugart
Associates and then at Adaptec.

5.  The Small Computer System Interface is a set of parallel
interface standards for attaching disk drives, printers,
scanners and other peripherals to the computers.
 it’s a drive interface standards that had been around as
long as the earliest ATA standards.

6. Internal SCSI
• Internal SCSI device are installed inside the pc &
connect to the host adapter through the internal
connector.
• Multiple internal devices can be connected together
by using a cable with more connector.

7. External SCSI
• External SCSI devices are connected to the host adapter
through the special SCSI external connector of the host
adapter
• All external connection have two connection it the back to
allow for daisy chaining of multiple external devices.

8. SCSI Host Adapter
• A SCSI host adapter is a device used to connect one
or more other SCSI devices to a computer bus.it is
commonly called a SCSI controller, which is not
strictly correct as any component understanding the
SCSI protocol can be called a controller.

9. Types of SCSI
SCSI 1 (Narrow SCSI)
• It’s used 50 pin cable with maximum transfer rate 5MBps &
it used 8 bit bus and support a maximum 8 device (HD)

10. SCSI 2
• It used 25,50 or 68 pin cable with a transfer rate of
10MBps it originally used 8 bit bus but an
enhancement fast wide SCSI that uses 16 bit bus &
support 16 device with transfer rate of 20MBps.

11. SCSI 3
• It uses 50,68 or 80 pin cable & the most common cable is
80 pin single connector attachment(SCA) it’s also called
ultra SCSI .also used 16 devices connected.
• Types speeds(MBps) speeds(Gbps)
• Ultra 160 160 MBps 1.28Gbps
• Ultra 320 320 MBps 2.56 Gbps
• Ultra 640 640 MBps 5.12 Gbps

12. SCSI ID
• SCSI device are control by SCSI controller each
devices including the controller is assign SCSI ID
using number from 0 to 15 the controller is
normally assign the highest priority SCIS ID of 7
.it’s used a controller ID

13. Daisy Chaining
• SCSI designs are connected together in a daisy
chain fashion which indicate are devices are
connected each other likes links in a chain state of
been connected directly to a central devices. SCSI
controller is an expansion card plug into the
motherboard & it has an internal devices an as
external devices.

14. Terminator
• Each devices has two connector to support daisy
chain connection . Additionally the last device the
chain must be terminate to late the controller
known that there are not any additional devices in
the chain.

15. Advantage
1. Its performance is much faster than IDE or SATA.
2. Many devices (nearly 16) can be attached at the
same time on a single controller.
3. The interfacing for different types of devices is
done through the same cable.
4. The peripheral devices of the same type have
common characteristics so it is easy to replace the
old devices.
5. The peripheral devices are independent so the
computer can do other work.

16. Disadvantage
1. The SCSI drives and hardware are more
expensive than IDE or SATA.
2. It may be difficult to configure older models
because each device needs a special ID number
and correct termination.