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عرض كامل الموضوع : أرجو المساعده!!



زهره السوسن
23-11-2003, 05:03 PM
السلام عليكم

لو سمحتوا عندي طلب صغير مرررره

واتمنى منكم انكم تساعدوني!!

انا عندي كتابه تقرير عن أي جزء في الحاسب الالي

مشكلتي اني قعدت ألف المواقع ومحركات البحث

بس مالقيت مواضيع تستاهل!!

اللي القاه صعب أو قصير أو..الخ

فاتمنى من أي احد منكم يعرف مواقع حلوه تتكلم عن أي شي

عن الكمبيوتر لا يبخل علي

على فكره الموضوع لازم يكون بالانجليزي ويكون يستاهل

وشاكره لكم ومقدره تعاونكم

اختكم

زهره السوسن

ra3ad
23-11-2003, 06:47 PM
سلام عليكم

عندك شي خاص تبحث عنه ؟؟

ولا اى شي بالكمبيوتر وملحقاته؟


تحياتي

زهره السوسن
23-11-2003, 10:29 PM
هلا اخوي رعد:

لا ماعندي موضوع خاص بس على فكره ابيه موضوع سهل وواضح

يعني عن input /output device أو عن اي شي سهل

لانه الماده هذي ماهي تخصص بس يبغون يعلمونا كيف نكتب تقرير

وطبعا الاستاذه تبغى نكتب لها تقارير من نفس تخصصنا

قسم بالله بلشه!! :cry: :cry:

ودي بالموضوع بهذي الفتره عشان اخلص منه بالاجازه وافتك

وآآآآآآآآآ سفه على ازعاجكم معي

تحياتي للجميع

ra3ad
24-11-2003, 01:12 AM
هذا بحث عن الهارد دسك
مكون من 1308 كلمة

وان لقيت زياده او شي ثاني بكتبه هنا :wink:

[left]Hard Drives


Hard drives have been around longer than you think. In 1956, I. B. M. had invented a disk storage unit that was very large but did not store a lot of data. It was twenty-four inches in diameter and could hold only five megabytes, which is the equivalent to three and one half floppy disks. Originally called “fixed disks” later became known as “hard disks” opposed to floppy disks. In 1973, I. B. M. released a hard drive that could hold seventeen and one half megabytes. In 1980 Seagate made the first five and one quarter inch hard disk. In the late 1980’s, three and one half inch hard disks were invented (PCIN). Although there are smaller hard disks as small as two inches in diameter, three and one half inch hard disks have been made a standard and is used most often today. The capacity in hard drives has excelled thousands of times all over from five megabytes to one hundred sixty gigabytes (160,000 megabytes) which is the equivalent to one hundred eleven thousand one hundred eleven floppy disks. The hard drive or hard disk is one of the most critical components in the operation of a computer. It is also one of the only moving parts in the computer. Sadly, many people do not know the important role it has in the storage of their data or how it even works.

When you think of your hard drive, think of it as the computer’s electronic filing cabinet. Everything you load, download, or save is stored on the hard drive. In fact, ten percent of your hard drive is already used when you purchase your computer because it needs certain system operating files that are required to make the basics work. Everything you add later such as word processors, antivirus software, e-mail software, games, and internet software are extra, soon leading to an over stuffed filing cabinet (Matthew Ferrara Seminars). However, many people ask, “What is the hard drive, physically?” The hard drive can be commonly referred to as “a box”. That is what it looks like, a three and one half inch metal box. It is located inside your mainframe or tower. It sits in what is called a drive bay. Here it is secured with screws. On the bottom of the hard drive is a chip board which is the really technical and complicated pieces of the hard drive. On the back there are groups of pins, three groups. One group has 40 small pins which is where the data cable plugs into. The second group there is a set of five or six pins, these are used to control and identify where the hard drive fits into the great scheme of things in the computer. It is set as master or slave. Most single hard disk computers are set to master. Usually your computer sees it as C drive. A jumper, which is a little plastic cap, is used to connect certain pins accordingly. The last group of pins is where the power cable plugs into. There are four thick pins here (Dusty’s World).

So what is inside this box? A rare few have seen the inside of a hard drive. Inside is a clean, sterile environment sealed off from all light and dust. If you were to open the cover of the hard drive, you will expose it to all these elements, ultimately ruining the drive (Dusty’s World). The first thing that is very noticeable is the stack of round, very shiny, electro-magnetically charged metallic disks called “platters” (Marshall). This is where your data is physically stored. The surfaces of these platters are divided into cylinders, tracks, and sectors. These are the coordinates that are used to locate data on the platters. In the middle of these platters is the spindle. This keeps the disks in constant circular motion. Drives are often categorized by how fast they spin, this is measured in RPM (Revolutions Per Minute). The average hard disk spins in between 5400-7200 RPM. A SCSI (Small Computer System Interface), pronounced “scuzzy”, hard drive can spin up to 15000 RPM, which is twice as fast as the engine in your car could ever go (Smart Computing). This very fast type of drive is mostly used in web servers where the speed is needed. Data is written and retrieved through a very small magnet called the “read/write head”. There is a head on the top and bottom of each platter. These heads are attached to the “access arm”. This extends the magnets out over the platters so it can access all areas of the drive. The access arm is attached to a device called the “head actuator”. This device uses a magnet, like a motor, to turn forty-five degrees to each side which in turn moves the access arm and the read/write head on the platter (Smart Computing). The speed of these three parts is measured in milliseconds called the average “seek” time. This is the average time that the read/write head takes to reposition itself and move from one sector to another. On most new drives, the average seek time is nine milliseconds (Marshall). From this point, all the data is send back and forth through the data cable to your motherboard.

The fact that these are physical parts created a problem. The rest of your machine transfers data electrically, but your hard drive does not. Engineers have developed a technology called Ultra DMA (Direct Memory Access) to overcome the speed bottleneck. The RAM (Random Access Memory) in your computer is faster than your hard drive, so this provides a direct link in between the two. It can pre-fetch data at rates of thirty-three to one hundred thirty-three megabytes per second (Smart Computing). Over time, your hard drive has read and wrote millions of times, this can potentially leave gaps in the organization of your data. This is called fragmentation. Most operating systems such as Windows come with a program to defragment your drive. This reorganizes the data so that it is in order. That means that your disk and read/write head doesn’t have to travel as far to access data. This in turn can speed up your system (Smart Computing). The organization of your data is important in order to have a stable system. There is a very important part of the hard drive that is vital in order to do anything. It is called the MBR (Master Boot Record). When you turn on your machine, the BIOS (Basic Input Output System) does its tests, then it passes control over to the MBR. This is located in the first sector of your hard drive. This is where your operating system stores information to load itself (PCIN). Many viruses often attack this part of the drive because with out it, the hard drive is useless. You will have to “format” the drive, which means you clean it off and start fresh. Another part of the file system is the FAT (File Allocation Table) this organizes data into “clusters” which are basically blocks of data. There are to kinds of FAT. There is FAT16 and FAT32. Older drives used to use FAT16, but drives became bigger and bigger in size and could no longer use FAT16 efficiently, so they made FAT32, which is faster and allows for more space (Powerload).

Just like any electronic device, they can fail. It is important to maintain your hard drive in order to predict and prevent failure. Doing regular tests and diagnostics should ensure a healthy drive. Also listen for funny noises or odd errors in your machine and remember to always make backup of your important data, after all, it is better to be safe than sorry![/center]



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زهره السوسن
24-11-2003, 01:26 AM
هلا بك اخوي رعد

والله احرجتني ثقلت عليك

بصراحه الموضوع حلوووووو ومفيد بس :cry: :cry:

مشكلته انه قصيرررررررر

انا ابي موضوع بحدود صفحتين يعني اربع ورقات :cry: :cry:

والله آسفه تعبتك معي

على العموم اذا ممكن تعطيني الرابط حق الموضوع وانا ادور يكون افضل

لاني ماودي اتعبك معي


وتسلم

تحياتي لك

زهره السوسن :lol:

ra3ad
24-11-2003, 01:33 AM
هلا

مشكله المواقع الى الان كلها لازم تشترى البحث :(

وان شاء الله القى شي زين

عموما ترانى استخدمت خط حجم 14 وصار البحث 3 صفحات.. ولو تحطين صور يمكن يصير 6 صفحات :)

.تحياتي.

ra3ad
24-11-2003, 01:36 AM
لقيت هذا جربيه

http://www.essaydepot.com/science/technol/index.php


واذا تبين تبحثين ابحثى عن هذى الكلمه

Essays (بحوث)

input /output device essay

زهره السوسن
24-11-2003, 02:10 AM
هلا فيك اخوي رعد

صراحه الموضوع حلو ونفسي اسويه بحث

بس زي ماقلت لك قصير شوي لاننا لازم نختصره

على العموم اذا عندك اي اضافه عن الهارديسك اكون ممنونه لك

مشكور على الرابط ..

وشاكره لك ومقدره وقفتك معاي اللي اعتبرها وسام على صدري

ويارب اردها لك مستقبلا

تحياتي لك

زهره السوسن

ra3ad
24-11-2003, 03:01 AM
اهلين

وهذا موقع فيه اكثر من 450 بحث عن الكمبيوتر ومشتقاته من اجهزة وبرمجه وانتر نت وشبكات و و و.....

http://www.fofweb.com/Subscription/Science/Helicon.asp?SID=1&Rec_Title=Computer+Science&RecordType=Essay


البحوث صغيره لكن بامكانك الجمع بين كم بحث حتى تصبح كبيره مثلا

Hard disk & CD ROM's
او
Data Procesing & Bios

لك الخيار :)

تحياتي

ra3ad
24-11-2003, 04:12 AM
[size=16:][align=left:]

[b:][color=darkblue:]Introduction to Hard Disks[/color:][/b:]

Nearly every desktop computer and server in use today contains one or more hard-disk drives. Every mainframe and supercomputer is normally connected to hundreds of them. You can even find VCR-type devices and camcorders that use hard disks instead of tape. These billions of hard disks do one thing well -- they store changing digital information in a relatively permanent form. They give computers the ability to remember things when the power goes out.


In this Essay, we'll take apart a hard disk so that you can see what's inside, and also discuss how they organize the gigabytes of information they hold in files!


[b:][color=darkblue:]Hard Disk Basics[/color:][/b:]


Hard disks were invented in the 1950s. They started as large disks up to 20 inches in diameter holding just a few megabytes. They were originally called "fixed disks" or "Winchesters" (a code name used for a popular IBM product). They later became known as "hard disks" to distinguish them from "floppy disks." Hard disks have a hard platter that holds the magnetic medium, as opposed to the flexible plastic film found in tapes and floppies.
At the simplest level, a hard disk is not that different from a cassette tape. Both hard disks and cassette tapes use the same magnetic recording techniques described in How Tape Recorders Work. Hard disks and cassette tapes also share the major benefits of magnetic storage -- the magnetic medium can be easily erased and rewritten, and it will "remember" the magnetic flux patterns stored onto the medium for many years.

Let's look at the big differences between cassette tapes and hard disks:

The magnetic recording material on a cassette tape is coated onto a thin plastic strip. In a hard disk, the magnetic recording material is layered onto a high-precision aluminum or glass disk. The hard-disk platter is then polished to mirror-type smoothness.
With a tape, you have to fast-forward or reverse to get to any particular point on the tape. This can take several minutes with a long tape. On a hard disk, you can move to any point on the surface of the disk almost instantly.
In a cassette-tape deck, the read/write head touches the tape directly. In a hard disk, the read/write head "flies" over the disk, never actually touching it.
The tape in a cassette-tape deck moves over the head at about 2 inches (about 5.08 cm) per second. A hard-disk platter can spin underneath its head at speeds up to 3,000 inches per second (about 170 mph or 272 kph)!
The information on a hard disk is stored in extremely small magnetic domains compared to a cassette tape's. The size of these domains is made possible by the precision of the platter and the speed of the medium.
Because of these differences, a modern hard disk is able to store an amazing amount of information in a small space. A hard disk can also access any of its information in a fraction of a second.
A typical desktop machine will have a hard disk with a capacity of between 10 and 40 gigabytes. Data is stored onto the disk in the form of files. A file is simply a named collection of bytes. The bytes might be the ASCII codes for the characters of a text file, or they could be the instructions of a software application for the computer to execute, or they could be the records of a data base, or they could be the pixel colors for a GIF image. No matter what it contains, however, a file is simply a string of bytes. When a program running on the computer requests a file, the hard disk retrieves its bytes and sends them to the CPU one at a time.

There are two ways to measure the performance of a hard disk:

Data rate - The data rate is the number of bytes per second that the drive can deliver to the CPU. Rates between 5 and 40 megabytes per second are common.
Seek time - The seek time is the amount of time between when the CPU requests a file and when the first byte of the file is sent to the CPU. Times between 10 and 20 milliseconds are common.
The other important parameter is the capacity of the drive, which is the number of bytes it can hold.


[b:][color=darkblue:]Inside a Hard Disk[/color:][/b:]

The best way to understand how a hard disk works is to take a look inside. (Note that OPENING A HARD DISK RUINS IT, so this is not something to try at home unless you have a defunct drive.)
Here is a typical hard-disk drive

[img:]http://static.howstuffworks.com/gif/hard-disk1.jpg[/img:]


It is a sealed aluminum box with controller electronics attached to one side. The electronics control the read/write mechanism and the motor that spins the platters. The electronics also assemble the magnetic domains on the drive into bytes (reading) and turn bytes into magnetic domains (writing). The electronics are all contained on a small board that detaches from the rest of the drive:


[img:]http://static.howstuffworks.com/gif/hard-disk2.jpg[/img:]


Underneath the board are the connections for the motor that spins the platters, as well as a highly-filtered vent hole that lets internal and external air pressures equalize:


[img:]http://static.howstuffworks.com/gif/hard-disk5.jpg[/img:]

Removing the cover from the drive reveals an extremely simple but very precise interior:



[img:]http://static.howstuffworks.com/gif/hard-disk8.jpg[/img:]


In this picture you can see:

The platters, which typically spin at 3,600 or 7,200 rpm when the drive is operating. These platters are manufactured to amazing tolerances and are mirror-smooth (as you can see in this interesting self-portrait of the author... no easy way to avoid that!).

The arm that holds the read/write heads is controlled by the mechanism in the upper-left corner, and is able to move the heads from the hub to the edge of the drive. The arm and its movement mechanism are extremely light and fast. The arm on a typical hard-disk drive can move from hub to edge and back up to 50 times per second -- it is an amazing thing to watch!
In order to increase the amount of information the drive can store, most hard disks have multiple platters. This drive has three platters and six read/write heads:

[img:]http://static.howstuffworks.com/gif/hard-disk7.jpg[/img:]

[img:]http://static.howstuffworks.com/gif/hard-disk10.jpg[/img:]

The mechanism that moves the arms on a hard disk has to be incredibly fast and precise. It can be constructed using a high-speed linear motor

[img:]http://static.howstuffworks.com/gif/hard-disk11.jpg[/img:]


Many drives use a "voice coil" approach -- the same technique used to move the cone of a speaker on your stereo is used to move the arm.


[b:][color=darkblue:]Storing the Data[/color:][/b:]

Data is stored on the surface of a platter in sectors and tracks. Tracks are concentric circles, and sectors are pie-shaped wedges on a track, like this:

[img:]http://static.howstuffworks.com/gif/hard-disk-track.gif[/img:]

A typical track is shown in yellow; a typical sector is shown in blue. A sector contains a fixed number of bytes -- for example, 256 or 512. Either at the drive or the operating system level, sectors are often grouped together into clusters.

The process of low-level formatting a drive establishes the tracks and sectors on the platter. The starting and ending points of each sector are written onto the platter. This process prepares the drive to hold blocks of bytes. High-level formatting then writes the file-storage structures, like the file-allocation table, into the sectors. This process prepares the drive to hold files. [/align:][/size:]


وهذا الرابط فيه نفس الكلام
http://computer.howstuffworks.com/hard-disk.htm

زهره السوسن
24-11-2003, 04:29 AM
هلا أخوي رعد

قسم بالله طاح وجهي منك


كلمه مشكوررررررر قليل بحقك

كفيت ووفيت وآآآآآآآآآآآآآآآآآآآآسفه اني غثيتك بطلباتي


تسلم والله على الصور والتكمله للموضوع وعلى الروابط

ان شاء الله اردها لك في الجايات

من جد انحرجت منك :oops: :oops:

تحياتي لك

اختك زهره السوسن

ra3ad
24-11-2003, 04:34 AM
اهلين

لا شكر على واجب الله يسلمك


بالخدمه ان شاء الله
واى بحث ترانى مستعد او غيرى بالمنتدى

ومنها نفيد ونستفيد :)


وكل عام ونتم بخير


تحياتي

زهره السوسن
24-11-2003, 04:37 AM
تسلم والله اخوي رعد

هذا العشم والله فيك وبأعضاء هذا المنتدى


وكل عام وانت واعضاء المنتدى بصحه وسلامه



تحياتي لك

زهره السوسن :oops:

السلطان
27-11-2003, 07:22 PM
ra3ad,

ألف شكر لك اخوي ra3ad على هالمعلومات..

وان شاء الله ماننحرم منك ومن خبرتك :)

تحياتي لك وللاخت زهره السوسن