Which disk is flexible to work

Although they cannot store as much data as convential disks and the data cannot be retrieved as easily, floppy disks have become extremely popular in situations where flexibility, low cost, and easy use are important. Today, the floppy disk has become an indispensable tool for people working with personal computers and word processors.

The principle of magnetic recording is fairly simple. The magnetic recording writing and playback reading are carried out by a computer's disk drive, whose function corresponds broadly to that of an audio record player.

Data transferred from the computer to the floppy disk is relayed in the form of a binary code and received in the form of magnetic pulses, while the disk in turn conveys magnetic patterns that the computer receives as a binary code. This code uses only l's and 0's, which the disk represents as single magnetic pulses and the absences of pulses, respectively.

Binary code is used because it most effectively utilizes the natural two-state characteristics of electricity and magnetism. To record information on a disk, a magnetic head contacts the disk's recording surface and magnetically imprints data onto it, translating the computer's binary codes into the disk's magnetic pulses.

Once a magnetic pattern consisting of many pulses and absences has been recorded, the disk retains the encoded information just like a permanent magnet. Retrieving info from the disk involves the opposite process. The magnetic head senses the magnetic pattern on the disk's recorded surface and converts it back into an electronic binary code. The computer then "reads" this information, using it to perform calculations or translating it into letters and figures for display on the monitor.

Floppy disks are currently offered in three sizes: an 8-inch The hub is a stainless steel piece that accurately centers the disk on the drive shaft. The shutter, also stainless steel, protects the recording media. The storage capacities on an 8-inch disk range from kilobytes roughly , characters to 1.

Each type of floppy disk is further identified according to its recording density. A single-sided disk can store data on one side only, while a double-sided disk can store data on both sides.

Double density disks can store twice as much data as single density disks, and high density disks have a special coating that enables them to store even more data. The jacket is made of a vinyl polymer, polyvinyl chloride PVC , to protect the media against physical damage that might be caused by handling and storage. Inside the jacket, the liner consists of a special-purpose, non-woven, anti-static fabric that is laminated to the PVC during manufacture.

The liner continually cleans the disk by removing debris from the surface of the media. The recording media is a pliable layer of Mylar—a polyester film that is a trademark of the Du Pont Corporation—that is only 0. It is enclosed in a hard plastic cartridge that protects it from physical damage. The hub, which accurately centers the disk on the drive shaft, is made of stainless steel and attached to the media with an adhesive ring. The button that separates the two sides of the shell so the media can move freely inside is made of high-density plastic.

The write protect tab, which prevents data from being mistakenly recorded or erased, is plastic. The wiper tab, also plastic, puts pressure on the liner to allow uniform and continuous cleaning.

The spring-loaded shutter, which protects the media, is made of stainless steel. Hyperscale Data Center 3. Cloud Computing 1. Government Data Protection 6. Scale-out NAS 3. Appliance Optimized Storage 4. HPC, Data Center 8. Business Intelligence 6. Object Storage 3. Data Warehousing, Archiving 2. Backup Storage, Cold Storage 2. Content Repositories 6.

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Punched cards and punched tapes Punched cards, which we know as a way of storing and transmitting information for computers in the s, go back to pre-computer time. Namely, in , when perforated paper was used to control a loom. He used perforated paper in a roll so that the machine reproduced the pattern on the fabric. Bouchon's colleague, Jean-Baptist Falcon, replaced the paper tape with perforated cards fastened together. Own loom for coarse fabrics he created in Perforated cards allowed in automatic mode, almost without the participation of the master, to carry out a certain alternation of raising and lowering the warp threads in order to display a given pattern on the fabric.

Perforated cards in the Jacquard loom. The result of the Jacquard loom. In the weaving business, the Jacquard looms, improved and automated, are still used. But punch cards still work. Below you see an example of a punch card from the home economics site for the Brother machine - with a motorcyclist for a children's sweater. Card for modern knitting machine Brother Charles Babbage in built the first model of his difference machine, which consisted of rollers and gears rotated with a special lever.

Then he asked the British government to finance his future work. In the process, he faced many problems, so after nine years the work got up. Although partially the machine functioned and performed calculations. He later returned to work in Babbage even designed a printer for this huge calculator, which in was launched at the London Museum of Science. Punch cards were used to enter data into the memory: one mechanism with punch cards set the operations of the mill, the second controlled the transfer of data between the mill and the warehouse.

The output device, that is, the printer, could reproduce the result in one or two copies in the form of a print or punch it on punch cards. Punches for Babbage Analytical Machine In those same years, in the first half of the 19th century, the Russian inventor Semyon Korsakov worked on mechanical intelligent machines. He became one of the pioneers in the use of perforated cards in computer science.

In , he created his first device, operating on the basis of perforated tables and designed for the tasks of information retrieval and classification. It was a homeoscope with fixed parts. Each line of the homeoscope corresponds to a certain symptom - a symptom of the disease. In the vertical column was a set of signs - pathological symptoms, of which one or more characterized the disease.

The bottom line contained the solution to the problem - a medicine that will help with the disease. The homeoscope itself was a cylinder with pins. The operator selected symptoms from the first column — for example, a cough and a runny nose — and pushed pins. Then he led the cylinder to the right along the table: when the cells were perforated in the right places, the homeoscope stopped, and information on the treatment of the disease could be read in the bottom line.

It was a kind of Excel spreadsheet before spreadsheets , tailored to the needs of a doctor. Homeoscope with Fixed Parts The U. Census in took eight years, and the census took just a year. This difference is due to the introduction of a counting machine working on punch cards.