DIGITAL AUDIOTAPE(DAT)(1975)

STOCKHAM'S SOUND STREAMS, INC.,LEADS THE WAY IN AN ALTERNATIVE RECORDING SYSTEM.

Digital  tape format is a magnetic tape data storage format developed bu Sony. the cassette consist of two real with a helical scan process

Until the 1980 s, most commercial audio recording were made according to analog principles, with the original sound modulated onto another medium, the physical characteristics of which are directly related to the original sound. In contrast, digital recording sees the original sounds converted to digital information and stored as a series of 1s and 0s known as "bits"

Although the principles of digital digital recording were already in place in the late 1930, it was not until 1975 that a usable commercial system was developed, when Dr. Thomas Stockham (1933-2004) established sound stream, Inc., the first dedicated digital recording company. The original audio was passed through an analog digital converter (ADC), converted to 16-bit audio, and stored on a 1 inch(2.54 cm) Honeywell tape deck. To play back the sound, the digital analog converter(DAC). The system offered the highest quality sound without any of the problems a analog recording. Mechanical deficiencies comanly associated with analog equipment were radically improved.

Competing systems, such as those produced by 3M, Sony, and JVC appeared in quick succession, but for the rest of decades it was stockhams system that dominated. From the early 1980 s, the Sony DASH and Mitsubishi ProDigi formats rendered previous systems obsolete. At the same time Sony's DAT cassette format become the de facto standard for making digital stereo recording. All of these format remained in use until the early 1990 s, after which hard disk recording began its gradual domination.

DAT is a standard medium technology for the digital recording of audio on tape at professional level of quality

Microprocessor(1971)

HOFF'S INVENTION BRING COMPUTER TO MASSES.

An integrated circuits that contain all  the function of a central processing unit of a computer is called microprocessor. it is cheap and small in size and easy to use

At the end of the 1960s, Intels Ted Hoff was asked to design several different calculator for a Japanese client. The traditional way would have been to develop several different integrated circuits silicons   chips to do the work. Even though these were small enough to be put into handheld calculator, programmable computer, which could do a variety of jobs, were still huge device.

Combining the small size integrated circuit with a power of programmable computer was an inevitable idea. Hoff decided that he would make a single integrated circuit that could be programmed to do many different things. Joined by fellow engineers Stan Mazor and Federico Faggin , Hoff squeezed an entire computer onto a single silicon chips, pairing it with a small memory to give it its instruction .his range of calculator all used the same chip, but each one had different instructions to instruct it how to behave.

Intel quickly realized that they had, quite literally in the palms of their hands, a programmable, general purpose computer with the power of machines that a decade before had taken up entire rooms. Making a deal with the calculator manufacture, Intel kept the right to sell the chip to other people and released the Intel 4004 processor in 1971.

The 4004, the first commercial microprocessor, was also the first step in the revolution that would sweep the world during the 1970s and 1980s, taking computer from their air conditioned industrial servitude and bringing them to homes, car, and even washing machine.

the controllers based on microprocessor are available in home appliance, such as microwave oven, washing machine etc.it is also used in controlling various parameter like speed, temperature, pressure. these are used with suitable transduction. 

E mail (1971)

TOMLINSON DEVELOPS A PROGRAM ALLOWING COMMUNICATION BETWEEN COMPUTER NETWORK.

Messages that distributed by electronic means from one computer to one or more computer via network. more plainly email is a message that may contain text, images, or other attachment sent through a network to a specified individual or group of individual is called e mail.

In 1969 a company called bolt Barenek and Newman won the contract to develop a communication network called ARPANET that would enable scientists and researchers to use each others computer facilities. During it's development, an engineer named Ray Tomlinson started to experiment with the coding of two program. SNDMSG allowed members of same network to exchange message among one another, whereas CPYNET allowed file transfer to occur between two separate network. It occurred to Tomlinson that by combining the two he could create a system that would make message transfer possible between different user of independent network.

One of most significant decision by Tomlinson was his choice of the symbol to separates the users name from the host network name. It was a fairly logical choice, but one that revived the rather esoteric symbol and saved it from the brink of linguistic extinction.

Unaware of the global significance that the 200 lines of code that made up the email program would have, tomlinson neglected to note what he wrote in the first ever sent (he claims it was something banal like "QWERTYUIOP" or "TESTING  1 2 3 4").

Allegedly, when Tomlinson first demonstrated his program to coworker , latter told him not to show the system to anyone because it was not part of their job description . Tomlinson has since said that even though there was no direct stated objective to create email, the ARPANET project was in fact a giant and worthwhile investigation into the multifarious uses of computer communication

some people use internet based application and some use program on their computer to access and store the email

INTERNET(1969)

ADVANCED RESEARCH PROJECT AGENCY (ARPA) DEVELOPS THE FIRST COMPUTER NETWORK.

A Global computer network providing a variety of communication facilities and information consisting of interconnected network using standardized communication protocols. 

In 1963, the advanced research project agency unit, set up by the U.S defense department, began to build a computer network. Driven by fear of the soviet nuclear threat, it aimed to link computer at different location, so researchers could share data electronically without having fixed route between them, making the system less vulnerable to attack even nuclear ones.

Data was converted into telephone signals using modem, developed at AT&T, in the late 1950s. In the 1960s, key advance were made including "packet switching " the system of packaging, labeling, and routing data that enable it to be delivered across the network, between machines. Paul Baran  proposed this system, which broke each message down into tiny chunks. These would be fired into the network, which would then route the various pieces to the desired destination . so, if chunks of a message were travelling from Seattle to New York via Dallas, but Dallas suddenly went offline, the network would automatically route via Denver instead. Different parts or "packets" of a message would go by different route , before being reassemble back into original message at their destination, even if they arrived in wrong order. Baran published his concept in 1964, and five years later the new network called ARPANET went live.

As the threat of nuclear war receded in the early 1970s, ARPANET was renamed the internet and effectively opened to all users. Since then, the development of email, the creation of the world wide web, and browser technology has enabled the internet to become a rich communication facility.

the internet sometimes called "the net" change the life style of human beings. we can gather any information at any place at any time using internet

BALLOON CATHETER(1969)

FOGARTY INVENTS A NONINVASIVE CLOT BUSTING DEVICE.

A type of catheter incorporating a small ballon which may be introduced into a, duct, canal, blood vessel and inflated in order to clear an obstruction or dilate a narrowed region.

Thomas Fogarty was working as a scrub technician at the good Samaritan hospital, Cincinnati, Ohio, when he noticed the difficulty surgeon had in removing blood clot that formed in arteries and veins. The operation which often took nine to twelve hours to perform, necessitated opening up the entire length of the vessels and often resulted in the patient dying or having their limb amputated.

Fogarty devised a scheme that could be used to overcome the need for invasive surgery. It involved using a urethral catheter, which is flexible and strong enough to be pushed through a blood vessels and penetrate the blood clot.

Working in his, fogarty had the further inspiration to use the fly tying skill he had learned as a fisherman to attach "fingertip" of a latex glove to the catheter, which could then be inflated with saline once it was past the clot. The idea is that the balloon expands to the size of the artery and is then pulled back out, bringing the clot with it.

In 1961, fogarty's balloon Embolectomy catheter named for the clot removal procedure was used for a first time on a human patient. A small incision was made, and the catheter was threaded up through the patients blocked artery. When inflated and pulled back out, it did indeed bring the clot out with it.

Today fogarrtys balloon catheter is the still most widely used technique for blood clot removal. The technology has also been extended for use in angioplasty, where balloon are inflated to widen narrowing in the heart arteries that cause symptoms of angina.

renal denervation, cryoablation, balloon sinuplasty,TAVI (Transcatheter aortic valve implantation), drug delivery, stent delivery, balloon occlusion which are the common application for balloon catheters.

Far ultraviolet camera (1969)

CARRUTHERS ENABLES OBSERVATION OF TGE STARS.

Spectrograph or the the far ultraviolet camera was one of the experiments deployed on the lunar surface by the Apollo 16 Astronauts. it is used to obtain astronomical images and spectra in far ultraviolet region of the electromagnetic spectrum.

ultraviolet light is found beyond the violet end of our visible spectrum of light, toward the X Ray. It is given off by the sun and is harmful to living things, which is why we need to wear sunscreen when we go out in the sun. Fortunately for us, most of it is absorbed by earths atmosphere. 

Ultraviolet light from place other than sun can tell us a great deal about the universe specifically about stars that are between twice and ten times the temperature of the sun. Because earths atmosphere gets in the way, astronomers find it hard to see them. By the mid 1960, however, human were journeying beyond earths atmosphere  

Normal camera pick up only light around the visible spectrum, but on November 11, 1969, astrophysicist Dr. George Carruthers was a granted a patent for an "image converter for detecting electromagnetic radiation especially in short wave lengths". the far ultraviolet camera was a 3 inch(7.62 cm),48.5 pounds, gold plated apparatus that could see stars that are a hundred times fainter than those that can be seen with the human eye. The camera was sent up with Apollo 16 mission in 1972 and placed on The moons surface, allowing researchers to examine earths atmosphere for concentration of pollutants. In record nearly 200 images, giving astronomers data on over 550 stars, nebulae, and galaxies, as well as providing new views of earth. The camera looked into the ionosphere the highest part of our atmosphere and gave us some of our earliest solid data on the concentration of man made pollutants. carruthers was awarded national metal of technology and innovation the nations highest honor for technology acheivement.

CELLULAR MOBILE PHONE(1970)

JOEL OPENS UP A PORTABLE COMMUNICATION SYSTEM.

A cellular mobile phone is a telecommunication devices which uses radio waves over a cell (networked area). it is served through a cell site or base station at a fixed location, enabling the calls to transmit wirelessly over a wide range to fixed the landline or via internet, In 1970, when he was working as an electrical engineer at Bell labs, in Murray hill, New jersey, Amos Joel came up with an idea that worked so well that many of us it today without noticing that anything has happened at all. Joel had invented the idea of the cellular mobile phone.

Cell phone existed prior to 1970, but they had problem. Since each call was made on a single
channel, the number of simultaneous call was limited to the number of available channels. additionally the cell phone could not leave the base station area of coverage in which  the call was initiated or the connection to net work would be lost.

Joel's cellular mobile phone communication system proposed providing phone services to a geographic area by dividing up into many small, low powered base station or "cells." This network of the cell deal a greater number of simultaneous call by allocating a radio channels to a call in one cell and reusing the same radio channel in a number of other cells separated by enough distance to prevent interference. When a user traveled from the service area of one cell to another, the user 's phone call would not be disrupted as each cell would "hand off" to the other, switching cellular base station and radio channels without anyone noticing.

The key ingredient? A microprocessor that could make all the decision, find cellular base station, identify the phone , and control the connection as user moved through the network. Today's cell phone supports a number of additional services ,such as access to internet, messaging, and camera. mobile phone connected to a terrestrial cellular network of base station whereas the satellite phone connected to orbiting satellite.