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Hard Disk Drives
In a personal computer, a hard disk drive controls the positioning, reading, and writing of the hard disk, where data is stored.
4,496 Questions
There are many disadvantages of magnetic tape.
1. Mag tape is in physical contact with the recording heads, causing friction and wear.
2. Magnetic tape is an analog medium, even when digital data is being stored.
3. Tape can stretch or break, or lose its magnetic data due to age, heat or the Earth's magnetic field.
What is difference between ide sata and scsi hard disk?
For years the parallel interface has been widely used in storage systems. The need for increased bandwidth and flexibility in storage systems made the SCSI and ATA standards an inefficient option. A parallel interface is a channel capable of transferring date in parallel mode - that is transmitting multiple bits simultaneously. Almost all personal computers come with at least one parallel interface. Common parallel interfaces include SCSI and ATA. SCSI
(sku4zē) Short for small computer system interface, a parallel interface standard used by Apple Macintosh computers, PCs and many UNIX systems for attaching peripheral devices to computers. Nearly all Apple Macintosh computers, excluding only the earliest Macs and the recent iMac, come with a SCSI port for attaching devices such as disk drives and printers. SCSI interfaces provide for data transmission rates (up to 80 megabytes per second). In addition, you can attach multiple devices to a single SCSI port, so that SCSI is really an I/O bus rather than simply an interface. ATA
(Also known as IDE) is a disk drive implementation that integrates the controller on the disk drive itself. ATA is used to connect hard disk drives, CD-ROM drives and similar peripherals and supports 8/16-bit interface that transfer up to 8.3MB/s for ATA-2 and up to 100MB/s (ATA-6). So, what do parallel interfaces have to do with SAS (Serial Attached SCSI) and SATA (Serial ATA)? A lot, actually. It is the architectural limitations of the parallel interfaces that serial technologies like SAS and SATA address. In contrast to multiple parallel data stream, data is transmitted serially, that is in a single steam, by wrapping multiple bits into packets and it is able to move that single stream faster than parallel technology. Serial Attached SCSI (SAS)
Abbreviated as SAS, Serial Attached SCSI, an evolution of parallel SCSI into a point-to-point serial peripheral interface in which controllers are linked directly to disk drives. SAS is a performance improvement over traditional SCSI because SAS enables multiple devices (up to 128) of different sizes and types to be connected simultaneously with thinner and longer cables; its full-duplex signal transmission supports 3.0Gb/s. In addition, SAS drives can be hot-plugged. Serial ATA (SATA) Often abbreviated as SATA, Serial ATA is an evolution of the Parallel ATA physical storage interface. Serial ATA is a serial link - a single cable with a minimum of four wires creates a point-to-point connection between devices. Transfer rates for Serial ATA begin at 150MB/s. Starting with SATA, it extends the capabilities of ATA and offers transfer rates starting at 150MB/s and, after years of development, has moved to the mainstream of disk interfaces. The successor the SCSI interface is SAS at speeds of up to 3Gb/s. Additionally, it also addresses parallel interface issues such as drive addressability and limitations on the number of device per port connection. SAS devices can communicate with both SATA and SCSI devices (the backplanes of SAS devices are identical to SATA devices). A key difference between SCSI and SAS devices is the addition in SAS devices of two data ports, each of which resides in a different SAS domain. This enables complete failover redundancy. If one path fails, there is still communication along a separate and independent path. Cables & Connectors Another big advantage of SATA over ATA is the cabling and connectors. The serial interface reduces the amount of wires needed to transmit data, making for much smaller cable size and making it easier to route and install SATA devices. The IDE cables used in parallel ATA systems are bulkier than Serial ATA cables and can only extend to 40cm long, while Serial ATA cables can extend up to one meter. In addition to the cabling, a new design of connectors is also used that reduces the amount of crosstalk between the wires, and the connector design also provides easier routing and better air flow. The Benefits of SAS & SATA in Storage Serial interfaces offer an improvement over older parallel SCSI (with a serial version) in storage applications and environments. These benefits include better performance, better scalability, and also better reliability as the parallel interfaces are at their limits of speed with reliable data transfers. SAS and SATA drives can also operate in the same environment while SCSI and ATA cannot. For example, using faster SAS drives for primary storage and offloading older data to cheaper SATA disks in the same subsystem, something that could not be achieved with SCSI and ATA.
IBM was formed from a merger of three (at the time) major companies:
- the Tabulating Machine Company, founded by Herman Hollerith and based in Washington D.C.
- the International Time Recording Company, was a forming of a merger between 2 unknown comanies and Bundy Manufacturing Company. Founded by Harlow Bundy in Auburn, NY.
- the Computing Scale Corporation, founded by Edward Canby and Orange Ozias in Dayton, OH.
These three companies were merged to form the Computing Tabulating Recording Corporation. They were based in Endicott, NY. The name was changed by CTR President Thomas J. Watson I in 1924 to the International Business Machine company (IBM).
Today IBM is headquartered @ Armonk, NY. In 2009 they reported almost 104 billion dollars in revenue and employ almost 400,000 employees.
The best one is definitely a reinstall.
You can how ever try booting a operating system from DVD to access your files.
A few repairs can also be done by booting a Windows 7 DVD. Read up on "bootrec".
Which letter is assigned to the primary hard drive?
In Windows, it is called "C:" (without quotes).
In Linux, it is called "/" (also without quotes).
I don't know about Mac, sorry.
What is the difference between floppy disc and hard drive?
A hard disk (HD for short) and floppy disk (FD for short) both work in the same manner, except that on can hold more information. Both are a type of magnetic media which can have information written and erased many many times. A lot better than paper when you write something and erase many times, that paper gets thin, then GAME OVER! I am including a link to better explain this from "howstuffworks". I really love that site. I could spend all day on there reading about anything! About their differences. the most common floppy disks only hold about 3.14MB of data. Where an electric HD can hold almost any amount up to several terabytes today!! That is huge. The FD uses a mechanical motor to move the read/write armature that hovers over the FD material (most comparable to cassette tape material). This is where it changes the magnetic properties of the tape material, and bingo, last night's report is saved! The HD works in a similar fashion. HD's have dense metallic disks inside that can spin at thousands of RPM's (rounds per minute). As the disks spin a similar Armature that is is surrounded by some really powerful magnets changes the magnetic properties of the dense metallic disks and Bingo, last night's report, music, and the whole operating system is spinning virtually forever. That is the basics. Hopefully that sums things up in a nutshell. Visit that site at howstuffworks to really see a more in depth look at floppy disks & hard drives!
How do you boot up acer aspire 5630 without hdd password?
There are only 2 ways to delete an Acer Aspire HDD password and the first is to contact Acer Support for a HDD master password.
The other is by using commercial software.
It's called disk defragmenter. Windows has an in built disk defragmenter which I haven't found to be that good. Lot of times you would find that it starts from 0%. Primarily it is due to other programs running and accessing the disk.
So a better tool that I've used and I'm quite satisfied is Piriforms Defraggler (http://www.piriform.com/defraggler) Try it out once and I'm sure you'd also like it.
How do you reprogram a hard drive?
Unless you are a computer programmer, "reprogramming" is not what you want to do to your laptop. Look at the Related links below, for information on how to format your hard drive and install Windows.
Does A hard disk provides much less storage capacity than a floppy disk or zip disk?
Zip disks can hold 100 megabytes. Today's hard drives usually hold 250 gigabytes, smaller ones are around 100 gigabytes, and large ones are upwards of 500 gigabytes. One gigabyte is 1000 megabytes, so the typical hard drive can hold 2,500 times more than a zip disk.
To answer the question in one word, no.
hard
Can a hard disk read and write at the same time?
Not really.
A standard plate based hard disk (as opposed to SSD) can't read and write simultaneously. However, when for example you're copying a file within the same disk, it may seem that it's being done at the same time. In reality, your HDD first loads the copied file (or part of it) into RAM and then writes it but you see only one progress bar so you may think it's simultaneous.
Sometimes you can actually spot this. If the file to be copied has been loaded into RAM before, you'll see the progress bar moving very fast and slowing down later.
What are the two major technologies that are used for hard drives in todays computers?
A hard disk drive (HDD) is a non-volatile, random access device for digital data. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the platters.
Introduced by IBM in 1956, hard disk drives have fallen in cost and physical size over the years while dramatically increasing in capacity. Hard disk drives have been the dominant device for secondary storage of data in general purpose computers since the early 1960s, They have maintained this position because advances in their areal recording density have kept pace with the requirements for secondary storage. Today's HDDs operate on high-speed serial interfaces; i.e., serial ATA (SATA) or serial attached SCSI (SAS).
What are the advantages of using database system instead of file system?
1. Redundency of data means some information may be duplicated in several places in file processing s/y .this can also be refined through DBMS.
2. Accessing of data is difficult in file processing s/y .to access the different data
we requried different program many times in other word for different type application requried different application program .
3. Multiple user can access the same data in DBMS.
4.Security also provided by DBA(Database adminstraror).
How is a microprocessors speed measured?
Typically, microprocessors (like the ones found in computers), measure their speed in hertz. A hertz is the measurement of a cycle in a second. So, 10 hertz means 10 cycles per second.
In computing, a cycle (or, more specifically, a clock cycle) is the basic unit of measurement that the CPU uses to carry out instructions given to it by software. Therefore, in a CPU running at 900MHz, 900 million clock cycles will occur per second.
Software sends commands to the processor called, instructions. These commands are the basis for how all programs run on a computer and are handled by the computer in a very complicated manner.
However, a computer running at 3GHz, for example, is not performing 3 billion instructions per second. Some instructions take multiple cycles to complete and some can even have other instructions in the same cycle simultaneously.
To complicate matters further, it is not accurate to say that a higher speed processor is better than another one at a lower speed. Certain AMD processors, for example, run at lower speeds than comparable Intel processors of their family but, because they use different architecture, perform at the same (and, sometimes, higher) performance levels than CPU's with high clock speeds.
Also, processors with some sort of Hyper-Threading technology or, better yet, multiple cores (like Intel Core 2 Duo processors) will be rated at lowered speeds than other CPU's in their price range but, because of more than one (virtual) processor is running parallel to the others, more instructions are performed per clock cycle.
There are also a few more factors to consider but this is the gist of it.
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What is difference between external hard drive and external backup drive?
An external drive is the same as an internal drive just not installed inside the case. Meaning you can use it in exactly the same way as an internal drive.
A backup drive is usually a zip drive designed to back up you hard drive and isn't used as a hard drive itself. It is usually in the form simalar to a floppy disk that the backup information is copied to. You can then use the backup disk and drive to reinstall all of your information from your original hard drive back to the hard drive in case of a virus or manually removing something that was needed for the system to run.
Command to load sector sixth c drive?
Loads a file or the contents of specific disk sectors into memory. Used without parameters, the l subcommand loads the file you specified on the debug command line into memory, beginning at address CS:100. Debug.exe also sets the BX and CX registers to the number of bytes loaded. If you did not specify a file on the debug command line, the file loaded is the one you most recently specified by using the n (name) subcommand.
Syntaxl [address]l [address] [Drive] [FirstSector] [number]
Your external hard drive appears on your computer all right but you cannot access it?
I would try to connect the device to another computer to make sure its not just your computer. If both computers cannot see the data there is most likely damage to the FAT (file allocation table) and/or boot record or the transport hardware in the external enclosure is going bad. If you can physically remove the harddrive from the enclosure and directly connect to a motherboard, that may be another alternative. If all this fails, you may have to contact a data recovery company or try recovering data with a freeware data recovery program (or buy one)
Why do computer have hard disk?
Hard Disks (or hard drives) are mainly used for Primary Storage. Typically most of the data on the computer, and the operating system, are stored on the harddrive. Without a hard drive or similar long-term storage, you would have to store data in RAM. RAM is volatile (temporary) memory which clears when the computer is turned off. Whereas hard drives will store data reliably without power, provided the hard drive and computer are functioning correctly.
Hard drives may also be utilized as overflow space if the computer runs out of RAM. Which harddrives are much slower (typically 50-100 MB/s) than RAM (1,600-8,000 MB/s) it is also far, far larger. Most harddrives are from 80 GB to 2,500 GB these days. This allows virtually limitless space for RAM to overflow to, and allow the system to keep functioning in the event of a RAM shortage. Computers typically only have 4 to 32 GB of RAM.
