Day 15
TWO primary performance restraints for mass storage devices are:
a) Storage ability
b) Driver acceleration
*c) Disk Access Time
d) Route mobility
*e) Rate of transfer
What's the best way to protect your hard drive data?
*a) regular backups
b) periodically defrag it
c) run chkdsk at least once a week
d) run scandisk at least once a week
e) run a regular diagnostic
Which of the following is a type of preventative maintenance used on a hard drive?
*a) Disk check diagnostics
b) Head alignment diagnostics
c) Initializing
d) Uninstalling programs
It is most important to keep hard drives and diskettes away from? (choose two)
a) Telephones
b) Battery-operated devices
*c) Magnetic devices
*d) Temperature extremes
You are about to install a second IDE hard drive in a PC that has only one IDE adapter. Your first hard drive will still be the boot drive. How should the second drive be configured?
a) as a master
b) as a secondary
*c) as a slave
d) as a primary
e) as auto-select
The acronym HDI stands for:
a) Half duplex interface
b) Hard disk interface
*c) Head to disk interference
d) Help desk interference
A feature of EIDE is
a) Up to 6 drives
b) ATAPI
A hard disk is divided into tracks, which are further subdivided into:
a) clusters
*b) sectors
c) vectors
d) heads
How may bytes in one Sector
a) 64K
b) 2048
*c) 512
d) 1024K
Which would you have to upgrade to install an EIDE drive?
a) RAM BIOS
b) A 286 CPU
c) Serial board
d) ISA motherboard
*e) Controller board
The tracks on a hard drive are further divided into
a) clusters
*b) sectors
c) vectors
d) heads
To install a second IDE drive into a computer, you must:
*a) Set the master-slave jumper to slave on the second drive
b) Use the IDE configuration software to set the new drive as slave
c) Verify that you define the new drive as D: in the CMOS setup
d) Verity that you attach the drive to the connector at the end of the ribbon cable
SCSI Answers
The acronym SCSI stands for ____.
*a) Small computer systems interface
b) Super computer small interface
c) System configured size interface
d) Swift control software interupt
In the Binary numbering system, a (1) represents a jumper being shorted and a (0) represents a jumper being open. On a three-bit jumper block on a SCSI drive, how would an ID of logical 3 be set?
a) 100
b) 010
*c) 011
d) 101
With a 3 jumper shunt, what is the highest number that can be made using the binary numbering system?
a) 3
b) 5
*c) 7
d) 8
Which provides the fastest access to large video files?
a) Optical drives
b) IDE hard drives
*c) SCSI hard drives
d) EIDE hard drives
When connecting two external SCSI hard disks to a computer, where do you connect the second hard drive?
*a) Any open SCSI port on the computer
b) A Serial port on the first host adapter
c) An open parallel port on the computer
d) An open SCSI port on the first hard drive
Which of the following statements is true?
a) Two SCSI devices connected to a computer can have the same ID if they are both hard drives.
*b) Each SCSI device must have its own ID
c) All SCSI devices must have the same ID
d) SCSI ID's are irrelevant
When installing a SCSI CD-ROM drive, you must set the CD-ROM SCSI adapter to:
a) B0007
*b) An unused SCSI address
c) The same address as the SCSI device before the CD-ROM
d) SCSI ID=1
Which controller would support an external CD-ROM drive?
a) ESDI
b) ARLL
c) MFM
*d) SCSI
Which of the following FRUs would be considered both an input/output device?
a) Video board
*b) SCSI host adapter
c) System board CPU
Which of the following statements is true?
a) Two SCSI devices connected to a comptuer can have the same ID is they are both hard drives.
*b) Each SCSI device must have its own ID
c) All SCSI devices must have the same ID
d) SCSI ID's are irrelevant
Your PC has 2 SCSI devices, an internal SCSI harddrive and an external SCSI CD-Rom, which do you terminate?
a) the SCSI adapter card and the harddrive
b) the SCSI Harddrive
c) the SCSI adapter
*d) the SCSI harddrive and the CDRom
e) No need to terminate anything
Which type of interface provides for the fastest data transfer?
a) IDE
*b) SCSI
c) parallel
d) serial
e) ISA
The SCSI boot drive must be addressed as
*a) ID 0
b) ID 3
c) ID 1
The binary address of the SCSI host adapter is
*a) 0111
b) 1010
c) 1110
Which of the following will NOT be a SCSI device?
a) Hard Disk drive
b) CD-ROM drive
c) Tape Backup unit
*d) Floppy disk drive
What is the highest binary number that can be referred to on a three position jumper block?
a) 4
b) 6
c) F
*d) 7
HDD Review
What do we look for, when we are talking about the performance of a HDD?
How many pins are in a IDE cable?
How many pins in a ATA-66/100 cable?
What is a head crash?
HDD’s RPMs are from what to what?
Which is faster? IDE or EIDE?
What is the max number of IDE devices that we can install in one system?
How do we name these devices?
Name the steps to better performance on a HDD.
Advance technology has allowed EIDE drives to have ATA-66 and ATA-100 interfaces. Also, SMART (Self-Monitoring Analysis and Reporting Technology) is now on most EIDE drives. Other technologies are MR and PRML, these technologies are Magneto-Resistive and PRML digital data channel.
Questions?
Today’s lesson is on Floppy Disk and other Drives.
FDDs are a relic from the days when HDD were rare. They have stayed with us because they allow data to be moved from one machine to another without using a network. FDD are not really needed any longer, because today’s machines can boot up from the CD-ROM. Also, we have CD-RW drives now, which allow the user to write to CDs and use them as a FDD! CD-RWs can also reformat CD-RW disks to reuse them many times.
Questions?
Since FDDs are relics from the past, they are extremely slow and have very little space compared to today’s HDD. For example, a 100 Gig HDD can hold 70,000 FDD!
Our Microsoft OS reserves the drive letters A and B for FDDs.
Drive Table
|
Drive’s Name |
Capacity |
Transfer Rate |
Today’s Price |
|
5.25” Double Density |
360 KB |
.25 Mb/Sec |
N/A |
|
5.25” High Density |
1.2 MB |
.5 Mb/Sec |
N/A |
|
3.5” Double Density |
720 KB |
.25 Mb/Sec |
N/A |
|
3.5” High Density |
1.44 MB |
.5Mb/Sec |
$6 to $18 |
|
3.5” Extra High Density |
2.88 MB |
.5Mb/Sec |
$25.00 + |
|
100 Gig ATA-100 HDD |
100,000 MB |
Up to 800 Mb/Sec |
$270.00 |
Most BIOS automatically can detect the presence of 5 ¼ “ and 3 ½ “ drives. BUT if a FDD fails to work, then you can go into the CMOS BIOS setting and change the FDD capacities and then see if the disk works. If a good drive goes bad, try cleaning it. Often dust bunnies will collect near the heads, causing reading failures and may destroy Diskettes! BTW- I now have the Award BIOS passwords for all of our machines!
FDDs use IO controllers to open a data pathway between the computer and the FDD. In older machines, prior to the 486 DX2- 66, FDDs and HDDs used Controller cards, which were mounted in a free ISA slot. After 486 DX2- 66 Motherboards had controllers built into them. This reduce the cost of the PC and allowed motherboard engineers more control over the IO control chips being used on the Motherboard.
FDDs use RIBBON Cables to connect with the controller. When you look at a Ribbon Cable, you will notice a twist on one end. That twist tells us that that is the side of the ribbon to connect with the FDD. Note that there is a pin one on FDD as with HDDs! Therefore pin one must line up with the red strip on the ribbon cable. Drive A is always connected to the end of the cable(where the twist is). Dive B is always in the middle connector. BTW- Remember those old and slow ST506 HDDs? Well the FDD uses those cables!
The first PCs could not house a FDD or a HDD, because they were too large to fit within a PC’s case. Therefore, in order to work well, the FDD was external. Today’s palmtops and laptops, now use external FDDs for the same reason. These external drives can be configured into Drive Arrays. A Drive Array or RAID array is a collection of multiple independent drives in one chassis or multiple drives that act as one logical drive.
RAID levels
There are seven levels in RAID configurations
q RAID 0 Uses many drives to store data called striping. If one drive fails-all fail.
q RAID 1 Copies a drive as a backup. The copy is kept u-to-date.
q RAID 2 Rare- Uses Hamming Code (EC code) to detect errors in copies.
q RAID 3 Uses striping, but is able to recover from disk drive failure.
q RAID 4 Not produced
q RAID 5 This is the most popular Disk array. It mixes data and EC across many drives. They are resistant to failure, but tend to be slow, therefore high performance control cards with onboard RISC processors and plenty of “on-chip” cache is used to overcome RAID 5’s limitations.
q RAID 6 Acts like RAID 5, but adds a second error encoding method.
This is a standard for RAID, which is Failure resistant and allows drives to be pulled or added to a machine, without rebooting. It is also Disaster tolerant.
These are like FDDs, but are faster and hold more data. They are used as backups for systems, because users do not all have the same media. For example, some users use JAZ drives, while others use ZIP 100 or ZIP 200 drives, still others may use SyJet drives, or Sybase drives.
These drives hold between 40 MB and 2,000 MB of data.
Transfer rates are from 1.4 to 9 MB per second with seek times of 12 ms.
These drives range in price from $30 to $400.
Tape backups
Tape storage has provided a backup solution for many years. These drives provide a way to save large amounts of data in a safe manner. The interfaces for these drive include the following:
|
Interface |
Notes |
Speed |
|
Parallel |
Was very popular in the mid-90’s as an interface. Was easy to install. |
Slow |
|
Floppy Drive |
Very easy to install. |
Very, VERY SLOW |
|
SCSI |
For internal and external backups. High Price |
Very fast |
|
USB |
Very easy to install. Hot PnP, low cost. |
Very fast. Allows for over 128 devices. |
CD-ROM
CD-ROM has been a way to package music and software for over 20 years (It was in Japan first). Now we have CD-R CD-RW. CD-ROM stands for Compact disc- Read only memory. CD-R are CDs that can record data. CD-RW can re-write data on a CD-RW disc. CDs normally hold 650 MB of data.
CD Drives use “X” to tell the user of the read speed. 1X= 150 KB/S We have CLV and CAV drives. CLV stands for Constant Linear Velocity. CAV stands for Constant Angular Velocity.
CLVs were used in the older drives and can read from 1X to over 12X. These disks changes their RMP speed to provide a constant reading speed.
CAVs vary their speed so that the drive maximizes reading speed. These dives can have speeds from 12X to over 72X.
|
Drive Speed |
Min Transfer Rate |
Max Transfer Rate |
|
1X |
150 KB/S |
150 KB/S |
|
4X |
600 KB/S |
600 KB/S |
|
12X |
1,800 KB/S |
1,800 KB/S |
|
24X (CAV) |
1,400 KB/S |
3,600 KB/S |
|
50X (CAV) |
3,000 KB/S |
7,800 KB/S |
|
100X (CAV) |
6,000 KB/S |
15,600 KB/S |
DVD
DVD drives can store more data on their disk and can still read CDs. DVDs can store from 3.9 Gig to 9.4 Gig.
We now have DVD writers too!
These are called WORM or Write Once, Read Many drives. The data written on these devices is expected to last over 50 years. We hope that users will be able to fine devices to read that media!
Phase Change Optical Drives
These drives can read 5.25” disc of 850 MB, 1.2 GB, 2.3 GB, and 2.6 GB storages. They transfer about 4MB per second.
For lab work- – Optimizing a Hard Drive.
First run scandisk from within the systems tools in Win9X.
Then run defrag .
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