|
|
MINDPRIDE Computer Services |
| Home | About Us | Our Services | Contact Information | Tutorials, Articles & Dictionaries | Site Map |
|
|
History of Data Storage
Data Recovery History History of Data Storage History of Hard Drive Technologies Magnetic Storage Technologies Optical Storage Technologies Electronic Storage Technology Media Conversion Technologies
Data Recovery History Data recovery is a broad term that relates to the many ways to extract data from a damaged or inaccessible magnetic medium. Technology varies greatly, and there are no standards yet set for this type of service. The demand for data recovery is increasing steadily and throughout time numerous devices have been invented that have aided the data recovery process. The origins of data recovery can be traced back to the discoveries of Charles Babbage and Ada Lovelace. In 1833, Babbage began working on the creation of the first computer. This invention, later known as the Analytical Engine, was based on the components of the modern computer we use today. Babbage worked on plans for the engine for 11 years until he reported his developments at a seminar in Italy in the autumn of 1841. An Italian named Menabrea wrote a summary of this seminar and published the article in French. In 1843, Ada Lovelace translated this article and suggested to Babbage that she add her own notes. These notes turned out to be 3 times the length of the original article, and Ada and Babbage combined ideas to finish the creation of the Analytical Engine. Programs for the engine were punched on Jacquard cards; as a result the machine was known as the 'punch-card system'. However, before long Babbage and Lovelace ran into a problem: one of the punch cards was damaged extensively by Babbage in the handling process . Retrieving the lost data from the corrupted punch card turned out to be an extremely difficult task, one in fact that neither Babbage nor Lovelace could do. A more advanced data storage system was needed in order to correctly retrieve lost information. This was the first known instance of the need for data recovery technology. Over the years since the Analytical Engine was developed, the computer field (and consequently the data recovery field) has developed at an overwhelmingly rapid pace. As a result, the demand for new data recovery solutions has advanced at the same rate. An extensive array of new ideas and concepts have surfaced as technology has advanced. One of the major accomplishments in the computer field was the ENIAC in the 1940's. The ENIAC (Electrical Numerical Integrator and Computer) was the first multipurpose computer. Within the next decade computers began to be used commercially, largely due to the incredible accomplishments of the ENIAC. Not only were multipurpose computers able to store more information, but with the invention of the ENIAC, computer use became more common. Consequently, there was more room to store data and more people were using computers to store information. Another major advance in the industry was IBM's first magnetic tape drive vacuum column for data storage in 1952. This discovery further increased storage and processing capabilities of the computer. Before the column was introduced, weak magnetic tape was used to store data. The fragile magnetic tape was a reasonable means for storage but the frequency of breakage and sudden starts and stops was high. With the IBM vacuum column, the tape was held down by a vacuum during movement. The decrease in breakage resulted in a less occurrence of data loss and made data easier to retrieve when there was a problem. In 1962, the Logic probe was introduced. The Logic probe is used on electronic logic circuits to look into failed chips. While the Logic probe only indicates state changes, it helps to identify the basic reason a chip may be failing. In recent years, data recovery has continued to become a vital industry as computers become increasingly important in our everyday lives. MindPride is on the forefront of this rapidly changing field and is dedicated to retrieving the data important to you.
History of Data Storage
1832-1952
Sir Charles Wheatstone uses paper tape to store data. This technique for data storage was similar to punch cards, except that the tape was made to be fed continually through the machine.
Herman Hollerith, was looking for a faster way to conduct the U.S. census. He used cards to store data information which he fed into a machine that compiled the results mechanically. Hollerith, with his new machine, founded the Tabulating Machine Company which later became International Business Machines (IBM).
1952-1970
IBM created the first magnetic tape unit for data storage. Magnetic tape was much faster than punch cards.
IBM introduced the 305 RAMAC. The RAMAC could store five million characters (five megabytes) on fifty disks, each 24 inches in diameter. Its recording head could go directly to any location on a disk surface without reading all the information in between. This made it possible to use computers for airline reservations, automated banking, medical diagnosis and space flights.
With the introduction of the first storage unit with removable disks, the end of the punch card era was hastened. Each disk pack could hold two million characters (2 megabytes) or as much and 25,000 punched cards.
Reducing the distance between head and disk made it possible to nearly double recording density-writing information smaller and more packed together.
The floppy disk was invented, which ushered in the era of data portability and desktop computing.
1971-1980
The introduction of the 3340 Winchester drive set the industry standard for the next decade. It featured two spindles with a storage capacity of 30 million characters each.
The first two speed tape unit is used, raising streaming speeds to 160kb per second.
RAID (Redundant Arrays of Independent Disks) was first introduced. RAID employs two or more drives in combination for fault tolerance and performance. They are used frequently on servers but are not generally necessary for personal computers.
Hierarchal Storage Manager (HSM) provides system delivered migration of inactive data from the disk to a less expensive storage media.
1981-1990
Thin film head technology enabled the introduction of the first commercial disk drive capable of reading and writing three million characters per second. It offered 6000 times more storage per square inch that the original RAMAC disk drive.
The first use of data compaction occurs, thus saving computer users time and money.
The Data Facility Storage Management Subsystem (DFSMS) is the first full function, automatic environment for management of storage systems.
The first magneto resistant head enables one gigabyte per square inch recording.
1991-Present
The first one-gigabyte 3.5 inch disk drive is invented.
The first one inch high one-gigabyte disk drive which stores 354 million bits per square inch is made.
Highly parallel processing, multi-level cache, RAID 5, and redundant components allow outstanding new levels of mainframe storage.
Three billion bits per
square inch of magnetic recording is achieved-a new world record.
History of Hard Drive Technologies 1956 1961 1963 1970 1973 1980 Phillips introduces the first optical laser drive. 1986 The SCSI specification is completed. It is a bus which controls the flow of data between the processor and its peripherals. It can handle up to eight devices such as hard disks, CD-ROM drives, printers, scanners, etc. Throughout the years SCSI has evolved (examples below).
Level 0 provides
'data striping' (spreading out blocks of each file across multiple disks) but no
redundancy. This improves performance but does not deliver fault tolerance. The
collection of drives in a RAID Level 0 array has data laid down in such a way
that it is organized in stripes across the multiple drives, enabling data to be
accessed from multiple drives in parallel. 1992 1993 1997 1999
Magnetic Storage Technologies Magnetic storage is a storage medium commonly used for large
volumes of data (e.g., video, image, or remote sensing data). Magnetic tape
drives use magnetic tape to store the data. Large amounts of data are stored
through tape drives because the capacity on the drives is huge - three billion
(or three gigabits) of data per square inch can fit on a single magnetic disk. History of Magnetic Storage Technologies
Optical storage technologies Optical disk - a storage medium from which data is read and to which data is written by lasers. Optical disks can store much more data (up to six gigabytes) than most portable magnetic media. There are three basic types of optical disks: CD-ROM-Like audio CDs, CD-ROMs come with data already encoded onto them. The data is permanent and can be read any number of times, but CD-ROMs cannot be modified. The CD-ROM drive's nominal speed is the same as its transfer rate. Single-speed drives have a 150KBps transfer rate while the rate for 12X drives is 1.8 Mbps. It is expected in the future that manufacturers are likely to shift from CLV (constant linear velocity) to CAV (constant angular velocity). While CLV rotates at varying speeds, CAV moves the disk at one constant speed. While this may not sound like much of a change to most, the difference is that this method is easier on the spindle motor because it does not require the drive to change motor speed as often, resulting in an improvement in performance. WORM-Stands for write-once, read-many. With a WORM disk drive, the disk can be read and reread but once it is recorded it cannot be changed. After that, the WORM disk behaves just like a CD-ROM. The WORM drive is a high-capacity storage device and is best for storing archives and other large amounts of unchanging information. Erasable-Optical disks- can be erased and loaded with new data, just like magnetic disks. These are often referred to as EO (erasable optical) disks. These technologies are not compatible with each other. Each requires a different type of disk and drive. An optical disk drive reads and writes data onto the disk. The disk is read by means of laser, then a magnetic field in addition to the laser is employed to write data onto the optical disk. The disk is exposed to a magnet on the label side and to the laser on the other side. A laser is used for two primary reasons: to allow a tiny one-micron diameter spot to be heated by an optical lens and the laser has enough energy to instantaneously reach Curie temperature (Curie temperature is 300 degrees Celsius, the level at which the magnetic domain loses its characteristic as a magnet). Construction of the optical disk - The optical disk is
mostly made of polycarbonate. The poly-carbonate plate should always allow the
laser beam to transmit completely through the disk without a problem. Resin is
applied to the disk substrate to ensure that the disk is not harmed in any way
during the process (including heat damage, damage by impact, etc.). On the
poly-carbonate resin substrate are seven types of film. Reflective film improves
the read process. Protective film protects recording film. Both first and
Electronic Storage Technology Electronic storage technology includes what is commonly called RAM (Random Access Memory) . RAM is used to hold the operating system, data and application programs currently needed to complete tasks, enabling the computer's Central Processing System (CPU) to access information stored in memory quickly. When a command is entered from the keyboard, the CPU interprets the command and instructs the hard drive to load the command into RAM, where it is more accessible. RAM is faster to write to and read from than any other type of storage in a computer (including the floppy disk, hard disk, and CD-ROM). RAM is called "random access" because any storage location on the computer can be accessed directly. It is organized in a way that enables information to be stored and accessed directly to specific locations. RAM is small in size and in the amount of data it can hold. It can be compared to short-term memory, focusing on the work at hand. When there is not enough room in memory for all the data needed by the CPU, the computer has to create a virtual memory file. This is the equivalent of simulating additional RAM, a process called "swapping". On average, the CPU is 60,000 times slower in accessing the hard drive than in accessing RAM. Generally, the more memory a computer system has, the better
its performance. A typical computer could come with 32 million bytes of RAM and
a hard drive than can hold around 4 billion bytes. Most computers are designed
to allow for additional RAM to be added. The more memory your computer has the
faster applications run, and the easier it is to run several programs at once.
Main RAM includes dynamic and static RAM. Dynamic RAM (DRAM) is the least expensive type of RAM and requires frequent power refreshing after each read in order to keep the charge that holds its content in place. DRAM includes: Fast Page Mode DRAM, Enhanced DRAM, Extended Data Output RAM or DRAM, Double Data Rate SDRAM, Direct Rambus DRAM, Burst Extended Data Output DRAM, Synchronous DRAM, Nonvolatile RAM, Enhanced SDRAM, Ferroelectric RAM, PC100 SDRAM, and JEDEC SDRAM. Static RAM (SRAM) is more expensive but does not need to be refreshed after each read, so it is quicker to access. However, SRAM requires four times more space than DRAM. Burst SRAM is synchronized with the system clock to make it more easily synchronized with anything that accesses it, in order to speed up waiting time. Video RAM is basically just all RAM used to store image information for the display monitor. All kinds of video RAM are arrangements of dynamic RAM. Images are first read by the processor and then written to video RAM. From here, the data is converted by a RAM digital-to-analog converter into signals that are sent to the display presentation mechanism. Video RAM consists of RAMDAC (Random Access Memory digital-to-analog converter), Window RAM, Rambus Dynamic RAM, Synchronous Graphics RAM, Multibank Dynamic RAM, and Video RAM (the most common type). Flash memory (also called flash RAM) is a type of
memory that can be deleted and reprogrammed into units of memory called blocks.
While flash memory is not as useful as random access memory, it can be helpful
in holding control codes in order to make them easier to update and change. The
name "flash memory" is used because on the microchip, a section of memory cells
are erased in a "flash". Flash memory is used not only in computers, but in
digital cameras, cellular phones, and other devices.
Media Conversion Technologies Data conversion is the process of changing data from one format to another, or migrating data to and from various formats. Conversion is used to change data to the correct format to work with the system and software specified by the customer, or to convert data from an original application format to a more accessible form . The process of Media Conversion varies according to the situation. Different conversion methods are utilized according to cost and data accuracy. There are various types of Media Conversion, including word processor conversion, file conversion, image conversion, data base conversion, and computer systems conversion. Word processor conversion may be necessary when developing an application that needs to read and/or write various file formats. Word processor file formats are very complex and new formats are constantly being introduced, so the demand for conversion is high. File conversion is just converting files to a different format. It may be necessary in order to view multiple file types without the related application. For instance, instead of having to buy ten different types of word-processing software to view ten different files, the files can be converted to fit one word processing system. Image conversion may be used to gain access to the various image processing methods from your favorite application development environment. Some popular image formats are JPEG, Photo CD, PNG, PDF, and GIF. It may be necessary to convert an image to a different format in order to resize, sharpen, change color, or add certain special effects to meet your standards. Data base conversion is needed to change any files saved in an out-of-date database to a more modern data base program. More modern databases are generally more convenient and dependable so the advantage of data base conversion is obvious. Basically, there are two very general methods of conversion:
data and media. In general, Media Conversion is extracting the files off of the
source media, followed by backing up the files to the destination media. Two
types of Media Conversion are media transfer and media migration. The reasons
for media transfer may be to transfer archived data into a more convenient
format or to save on cost of equipment, and media migration may be utilized for
a greater storage capacity, a more reliable media type, less expensive media
cost per GB or flexibility of media. However, a full Media Conversion can be
much more |
Web Page Designed By
ADAM |
US
