Television

Braun HF 1 television receiver, Germany, 1958

History

In its early stages of development, television employed a combination of optical, mechanical and electronic technologies to capture, transmit and display a visual image. By the late 1920s, however, those employing only optical and electronic technologies were being explored. All modern television systems rely on the latter, although the knowledge gained from the work on electromechanical systems was crucial in the development of fully electronic television.

The first images transmitted electrically were sent by early mechanical fax machines, including the pantelegraph, developed in the late nineteenth century. The concept of electrically powered transmission of television images in motion was first sketched in 1878 as the telephonoscope, shortly after the invention of the telephone. At the time, it was imagined by early science fiction authors, that someday that light could be transmitted over wires, as sounds were.





Satellite

In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellite such as the Moon.

History's first artificial satellite, the Sputnik 1, was launched by the Soviet Union in 1957. Since then, thousands of satellites have been launched into orbit around the Earth; also some satellites, notably space stations, have been launched in parts and assembled in orbit. Artificial satellite originate from more than 50 countries and have used the satellite launching capabilities of ten nations. A few hundred satellites are currently operational, whereas thousands of unused satellites and satellite fragments orbit the Earth as space debris. A few space probes have been placed into orbit around other bodies and become artificial satellites to the Moon, Venus, Mars, Jupiter and Saturn.

Satellites are used for a large number of purposes. Common types include military and civilian Earth observation satellites, communications satellites, navigation satellites, weather satellites, and research satellites. Space stations and human spacecraft in orbit are also satellites. Satellite orbits vary greatly, depending on the purpose of the satellite, and are classified in a number of ways. Well-known (overlapping) classes include low Earth orbit, polar orbit, and geostationary orbit.

Satellites are usually semi-independent computer-controlled systems. Satellite subsystems attend many tasks, such as power generation, thermal control, telemetry, attitude control and orbit control.

Radio

Radio is the transmission of signals by modulation of electromagnetic waves with frequencies below those visible light. Electromagnetic radiation by means of oscillating electromagnetic fields (modulating) some property of the radiated waves, such as
amplitude, frequency, phase, or pulse width. When radio waves pass an electrical conductor, the oscillating fields induce an alternating current in the conductor. This can be detected and transformed into sound or other signals that carry information

Mobile phone



A mobile phone (also called mobile, cellular telephone, cell phone, or hand phone (in Southeast Asian English) is an electronic device used to make mobile telephone calls across a wide geographic area. Mobile phones are different from cordless telephones , which only offer telephone service within a limited range of a fixed land line, for example within a home or an office.
A mobile phone can make and receive telephone calls to and from the public telephone networkwhich includes other mobiles and fixed-line phones across the world. It does this by connecting to a cellular network owned by a mobile network operator. 

 

8-inch, 5¼-inch (full height), and 3½-inch drives

8-inch, 5¼-inch, and 3½-inch floppy disks

History 

The earliest floppy disks, invented at IBM, were 8 inches in diameter. They became commercially available in 1971. Disks in this form factor were produced and improved upon by IBM and other companies such as Memorex, Shugart Associates, and Burroughs Corporation.

In 1976 Shugart Associates introduced the first 5¼-inch FDD and associated media. By 1978 there were more than 10 manufacturers producing 5¼-inch FDDs, in competing disk formats: hard or soft sectored with various encoding schemes such as FM, MFM and GCR. The 5¼-inch formats quickly displaced the 8-inch for most applications, and the 5¼-inch hard-sectored disk format eventually disappeared.

In 1984, IBM introduced the 1.2 megabyte dual sided floppy disk along with its AT model. Although often used as backup storage, the high density floppy was not often used by software manufacturers for interchangeability. In 1986, IBM began to use the 720 kB double density 3.5" microfloppy disk on its Convertible laptop computer. It introduced the so-called "1.44 MB"high density version with the PS/2 line. These disk drives could be added to existing older model PCs. In 1988 IBM introduced a drive for 2.88 MB "DSED" diskettes in its top-of-the-line PS/2 models; it was a commercial failure.





Playstation (PS)

 

 

 

History

PlayStation was the brainchild of Ken Kutaragi, a Sony executive who had just come out of his hardware engineering division at that time and would later be dubbed as "The Father of the PlayStation".

The console's origins date back to 1986 where it was originally a joint project between Nintendo and Sony to create a CD-ROM for the Super Famicom/SNES console.

The PlayStation made its debut at the Consumer Electronics Show in June 1991 when Sony revealed its console, a Super Famicom/SNES with a built-in CD-ROM drive (that incorporated Green Book technology or CDi). However, a day after the announcement at CES, Nintendo announced that it would be breaking its partnership with Sony, opting to go with Philips instead but using the same technology.

The deal was broken by Nintendo after they were unable to come to an agreement on how revenue would be split between the two companies.

The breaking of the partnership infuriated Sony President Norio Ohga, who responded by appointing Kutaragi with the responsibility of developing of the PlayStation project to rival Nintendo.

At that time, negotiations were still on-going between Nintendo and Sony, with Nintendo offering Sony a "non-gaming role" regarding their new partnership with Philips. This proposal was swiftly rejected by Kutaragi who was facing increasing criticism over his work with regard to entering the video game industry from within Sony. Negotiations officially ended on May 1992 and in order to decide the fate of the PlayStation project, a meeting was held in June 1992, consisting of Sony President Ohga, PlayStation Head Kutaragi and several senior members of Sony's board. At the meeting, Kutaragi unveiled a proprietary CD-ROM-based system he had been working on which involved playing video games with 3D graphics to the board. Eventually, Sony President Ohga decided to retain the project after being reminded by Kutaragi of the humiliation he suffered from Nintendo. Nevertheless, due to strong opposition from a majority present at the meeting as well as widespread internal opposition to the project by the older generation of Sony executives, Kutaragi and his team had to be shifted from Sony's headquarters to Sony Music, a completely separate financial entity owned by Sony, so as to retain the project and maintain relationships with Philips for the MMCD development project (which helped lead to the creation of DVD).

Scientific Calculator

Solar powered scientific calculator

Practical use of calculator

Practical use of calculator

A scientific calculator is a type of electronic calculator, usually but not always handheld, designed to calculate problems in science (especially physics), engineering, and mathematics. They have almost completely replaced slide rules in almost all traditional applications, and are widely used in both education and professional settings.

In certain contexts such as higher education, scientific calculators have been superseded by graphing calculators, which offer a superset of scientific calculator functionality along with the ability to graph input data and write and store programs for the device. There is also some overlap with the financial calculator market

The first scientific calculator that included all of the basic features above was the programmable Hewlett-Packard HP-9100A, released in 1968, though the Wang LOCI-2 and the Mathatronics Mathatron had some features later identified with scientific calculator designs. The HP-9100 series was built entirely from discrete transistor logic with no integrated circuits, and was one of the first uses of the CORDIC algorithm for trigonometric computation in a personal computing device, as well as the first calculator based on reverse Polish notation entry. HP became closely identified with RPN calculators from then on, and even today some of their high-end calculators (particularly the long-lived HP-12C financial calculator and the HP-48 series of graphing calculators) still offer RPN as their default input mode due to having garnered a very large following.

The HP-35, introduced on February 1, 1972, was Hewlett-Packard's first pocket calculator and the world's first handheld scientific calculator. Like some of HP's desktop calculators it used reverse Polish notation. Introduced at US$395, the HP-35 was available from 1972 to 1975. HP continues to develop and market high-end scientific calculators, like the HP-35s and HP-49 series, which have been favored by scientists and engineers, in labs, offices, as well as in the field