T12 GROUP 4

Earliest Forms of External Data Storage
Punched Hole Method

The first form of external data storage was technically the punch card. The punch card is a piece of stiff paper that has digital information represented by the presence or absence of holes in certain position. Early computers used these punch cards for both computer programs and data storage. The first real patent for this kind of data storage was patented in 23 Sep 1884 by Herman Hollerith. IBM originally obtained the rights to this technology. The 80 column Hollerith card became the main medium used for data storage and programming. The most common use originally was only to store the settings for different computers. UNIVAC then developed a 90 hole punch card which IBM also required the rights for. The amount of data for each card was extremely limited though.

As the first minicomputers began to surface punched cards were replaced by punched tape to increase the amount of data capable of being stored. Even with punched tape, data that was more than a few dozen kilobytes could not be stored because of the length of tape that would be required to store that data. Punched tape also had the problem of needing to be rewound after every use and the larger the dataset the harder it was to rewind without damage.

Magnetic Storage Techniques

Sometime in the 1950’s the first steps to magnetic data storage were taken when magnetic tape was first introduced by IBM to store data. One roll of the early magnetic tape could store as much data as 10 000 punch cards so it easily began to replace the punched hole method of storage and it became the most popular way of storing computer data until the mid 1980s. Initially magnetic tape for data storage was wound on 10.5 in reels and fed through floor standing tape drives. Early tape had 7 parallel tracks of data along the length of the tape allowing six-bit characters plus one bit for error detecting. This form of tape had a max of about 5mb of data storage. When IBM released its new computer that used 8-bit coding in 1964 a 9 track tape was developed. This new tape could store a max of 140mb. In the mid 1970’s tape cartridges and cassettes began to become available and were commonly used with small computer systems.

Floppy Disks
The first floppy disk was introduced in 1969. The first floppy disk was 8 inches and could store 80kb. By 1973 the same size disk could store 256kb of data and was readable and writable. The trend of smaller disks with more storage continued until the last generally adopted floppy disk was developed in 1987. This disk was 3.5in and could store 1.44mb. More attempts were made to improve on this further but the floppy disk had began to become obsolete to the newer forms of external data storage.

Pros: Paved the way for more advanced disk storage systems such as the CD, DVD, HD-DVD and Blu-Ray,

Cons: very small storage capacity, could be ruined by exposure to magnetic fields because it is a magnetic storage device, there were compatibility issues because if you didn’t have the right size drive the disk didn’t fit, in the beginning they were expensive as were the drives that they fit into.

CD
In 1979, Sony and Philips Consumer Electronics set up a joint project to design a new digital audio disc. The project progressed the research into laser technology and optical discs that had been started by Philips in 1997. The Compact Disk (CD) developed from this research which offers longer playing time and a high resilience against disc defects such as scratches and fingerprints. According the Philips, the Compact Disc was thus “invented collectively by a large group of people working as a team.”

CD disk’s was popular in the 90’s with the increase of computer usage. They were first mainly used by the music industry for media use; they developed a SACD (Super Audio CD) which could maximize the capabilities of high end audio devices during the time period. CD’s were also popular for computer software, and not just data storage. The CD’s were adapted into the console system known as the Play Station.

With the problems of compact disks not being fully used, if they were they would cause errors or quality would be reduced there was a force of advancement. Specifications such as the SACD were developed but weren’t used by the common consumer to pick up. Developments such as rewrite were largely used, and thus dual layered compact disks were developed by 5 different music companies at once, which features an audio layer on one side and a standard DVD layer on the other. This new type of compact disk offered more security to the information on it to lessen the piracy and to provide more to the people, but the advantages of the original compact disk were given up for this.

Pros: They are inexpensive and easily obtained, They are relatively light and easily portable, they are available in a rewritable version

Cons: They are not able to store quite as much as a blu-ray, they are fragile and scratching the surface of the disk can cause damage to the data on the disk, they have a fairly small ability to store data

Blue-Ray
Philips and Sony started two projects applying ultra density optical and DVR blue with Pioneer, this format of rewriteable discs would be eventually known as Blue-ray Disk which its main uses are for high definition video and data storage. It has the same physical features as the DVDs and CDs but because of the shorter wavelengths of the blue laser it can substantially hold more data.



Pros: Very large storage capability compared to DVD, improved graphics when used for movies, the players are able to play DVD and CD

Cons: More expensive than CD, the Blue Ray reading devices still remain expensive, only Blue Ray players are able to read Blue Rays meaning people who want to have Blue-Ray technology need to buy a new player

DVD
In 1993 two high-density optical storage formats were being developed; one was the MultiMedia Compact Disk (MMCD) by Philips and Sony, and the other was Super Density(SD) by Toshiba, Time Warner, Matsushita Electric, Hitachi, Mitsubishi Electric, Pioneer, Thomson, and JVC. They eventually combined their efforts and decided on the name of Digital Video Disk (DVD). It was first introduced in 1996 in Japan, 1997 United States, 1998 Europe, and 1999 Australia.

DVD's main uses are for data and video storage, but also have variations that are properly formated the type of storage such as DVD-Audio or DVD-Video. With the dimensions as compact disks, but store more than six times as much data they are becoming more popular.

Pros: accessible and affordable players for most people, they are able to store more information than CD, in the movie business as opposed to vhs they are more reliable because they are less easily damaged

Cons: with the popularity of Blue-Ray growing DVD are becoming more and more obsolete,

External hard drives
Pros: they are able to store massive amounts of information, they offer a more affordable option to people who need more storage space on their computer but don’t want to buy a new one, they are a better way to transport large amounts of information as opposed to moving a whole computer or putting it on many dvd or cd, they are compatible with most computers because to read it you don’t have to have a special drive or player

Cons: because they are a magnetic storage device as opposed to solid state they are susceptible to damage caused by bumps and jolts to the system as well as damage by other strong magnets

USB storage
Universal Serial Bus(USB) are originally developed for a single standardized interface socket which allowed hot swamping between many peripherals.USB is not intended to be a primary bus for a computer’s internal storage, but will appear as another internal drive.

The Ranges of a USB Mass Storage device typically can hold 1GB to 32GB in retail markets.

Pros: they are a quick way to move smaller amounts of information (up to ~32GB), they physically small, they are compatible with most computer systems because usb is a very common port in most computers, they are rewritable

Cons: for storing large amounts of information this is not a viable solution, the per GB cost is rather high

IPOD
IPod is an external data storage device that has been modified to play music, designed by Apple Inc. and it was first established on October 23, 2001. The idea started when the company began designing software for the growing market of personal digital devices. The IPod was developed in less than a year and has many adaptations to meet the demand for larger storage capacity and the ability to play media.

Memory Card
Memory card is a device that is small and thin plus it doesn’t need any power and easy to record or transmit information for one device to another. So is commonly used on must electronic devices like: computers, digital cameras and video games. It’s becoming the most well-used memory saving storage in nowadays



『CF』- Compact Flash, 『MD』- Micro Drive, 『SD』- Secure Digital & SDHC(SD2.0）、SD1.1、SD1.0、mini SD、Micro SD, 『SDHC』--Secure Digital High Capacity, SD 2.0, 『MMC RS-MMC』--- Multi Media Card, 『MS』- Memory Stick(MS → MS PRO → MS PRO DUO → MS Micro M2), 『XD』--XD-Picture Card, 『SM』--Smart Media