Today we are living in digital society. Due to rise of digital technology basic fabric of society is almost changed. For example, in India twenty years back, cellular phones were bulky and were a status symbol. Users seldom revealed their cell phone numbers, as incoming calls were also metered or charged. Now sleek cell phones are the norm and each Indian possesses a cell phone. The word “Privacy” is unknown to Indians earlier, now they practice it. Thus digital technology has started shaping the society. Earlier posts like tribal, agrarian and industrial society discussed length and breadth of technology-society association. In this post emphasis will on the digital technology.
Technology has so advanced that by click of a button we get any information we want. Is this means we are far superior than our ancestors? The answer is Yes and No. Internet has become giant virtual library. Internet contains lot of text information and videos which are structured, static and suited for one way communication (author to reader or viewers). We have honed our skills to surf and sift information from Internet. By this reason, yes is the answer. We lack the ability to communicate, leave alone extracting information from fellow humans. This is because human to human interaction is much unstructured, dynamic and two way (author to listener, and listener to author). Communication is complex and lot of training is required to excel [1]. We had fishermen, who observed the cloud and predicted the weather and other vital information required for fishing. In agrarian society humans acted as an information repository.
Today society banks more on man-machine interaction rather than human-human interaction. This may result in assorted individuals (Man, woman, boy and girl) instead of a family (Father, mother, son and daughter) staying in a house. Thus our challenge is to make the digital devices to assist us in improving human-human interaction.
Digital Devices
We come across devices like digital clock, mp3 player, audio compact disc player, Video Compact Disc (VCD) player, Digital Video Disc (DVD) player, computer, cellular phone, Tablet and so on. These diverse devices can be brought under umbrella of digital devices. Analog devices operate on analog signals which are continuous in time as well as in value. Digital signals are discrete in time and can hold only two values i.e. ones and zeros. Dominance of digital devices over analog counter parts is due to the axis of IC fabrication, Computer and Internet.
Benefits of digitalization are listed out;
- Instant and economical transport of digital data across the globe
- Compact storage – 100s of books can be stored in a single DVD
- Error free duplication – In analog domain while copying, addition of small amount of noise is inevitable. But in digital domain 100 % noise free duplication is possible.
- Error detection and correction – While transmitting or storage and retrieval error may creep in. But digital signals can be made immune by adding parity bits.
A digital device is expected to have following components.
- Computing machine – It may contain of any one of the following; microprocessor, microcontroller, Field Programmable Gate Arrays (FPGA), Digital Signal Processor (DSP) chips else combinations of above (for ex. microprocessor and DSP).
- Interface unit – It helps to connect it with the external analog world. For example, input to display devices (LCD or LED screen) are digital and output is analog. Input to cell phone is analog and output is digital coded data from vocoders (voice coders). Thus either analog-to-digital (A-to-D) or D-to-A is a necessity for digital devices
- Storage unit – Semiconductor memory ex. Flash memory is employed.
Metamorphosis of computers
Earlier day’s computers were designed to crunch numbers or data. These supercomputers were used for scientific and engineering research. In 1960s big corporation used mainframe computers, which were good at transaction processing. Examples for mainframe computers were IBM System/360, Digital Equipment Corporation's (DEC) PDP-8, PDP-10 and PDP-11 series. It used software like COBOL, DB2. Both (supercomputer and mainframe) were very costly and quantity produced was very less. Very few programmers were required to control the machines and they were professionals. In 1980s Intel introduced microprocessor '4004.' It started the Personal Computer (PC) or microcomputer era. Every tech savvy person dreamt to own one PC. This created a huge market for PC. As semiconductor especially silicon substrate was amenable to mass production and technological improvements, industries pumped billions of dollars in fabrication research and able to make complex IC with lesser cost. This resulted in fall of PC’s price and became affordable to most of the PC enthusiasts. Thus within a decade powerful PCs were in market with a nominal price tag.
Computer manufacturers understood that to maintain “PC buying spree,” they have make the computer more user friendly. They introduced office suite, video games and worked seriously on Graphical User Interface (GUI). Apple Mac pioneered in GUI, later Microsoft followed it. Computers become a glorified electronic typewriters and game consoles. Later frills were added and multimedia PC born. It had sound card, graphics card, and audio and video player software. Thus scientific elite data crunching machine become a commoner’s machine.
In 1960s electronic exchanges were introduced. Telecom engineers envisioned end-to-end digital telephone system. This resulted in Integrated Services Digital Network (ISDN). This helped to build digital exchanges and offer few new services (ex. Call diversion etc) to the users. ISDN was not implemented fully. In the mean time Internet started evolving. It helped to connect computers via Ethernet and telephone cables. UNIX system geeks were the first persons to enjoy the benefits of networking. They built Bulletin Board Services (BBS) and File Transfer Protocol (FTP) with anonymous user access facility. This helped to form a virtual community and access documents (mostly computer related) free of cost. Tim Berners Lee from CERN labs, created World Wide Web (WWW). This is the next democratization event after the arrival of PC. Users become “information volunteers” and poured necessary content to Web.
In the scientific field concepts like simulation and virtualization become buzz words. Scientists spent much time in programming than actual laboratory experimentation. This resulted in new fields like Computational Fluid Dynamics (CFD), Finite Element Methods (FEM) etc. Due to industrialization, need for new machine tools and machine was on rise. Machines become very complex, cost of building a prototype become high and time to build got shortened. These issues made use of computers in design of machines a must. Thus use of Computer Aided Design (CAD) and 3D modeling tools were developed. For that extensive graphics routines were developed. Thus lots of graphics stations were produced. Offshoots of computer graphics were given to video games. Lot of game consoles was created and all over the world children and adults are nearly addicted to them. These graphics routines were extensively used to create 3D animation movies.
Thus progress in IC fabrication, metamorphosis of computers and improvement in telephone networks were the pillars for the reign of digital devices.
Digital devices can be broadly classified into Digital Content Producing Devices (DCPD) and Digital Content Consuming Devices (DCCD). Examples for DCCD are VCD players, DVD players, digital cameras, scanners and so on. Huge computer industry helped mass production and cost of IC, hard disk, Compact Disk (CD) become cheaper day by day. Production of DCCD becomes economical and suitable for huge consumer market. Digital content carrier like audio CD and VCD were produced in millions. Arrival of mp3 (MPEG Audio Layer III) format gave a death blow to analog tapes. A 700 MB capacity CD can hold approximately 11 hours of stereo music. Likewise arrival DVD finished video cassette players. DVD had superior picture quality, required less maintenance and occupied less space. High quality scanners (around 600 dots per inch) flooded the market in affordable price. This helped to old documents to be scanned and stored in DVDs. Digital Single Reflex Camera (DSLR) with 10 Mega Pixels arrived in the market. High quality photographs were captured using Digital Camera and stored in DVDs.
Availability of economical hard disk with Terra byte size, powerful computer servers and availability of broadband service started the annihilation of CDs and DVDs. Today broadband enabled computer acts a radio, video on demand, photo album and so on.
All multimedia PC had high resolution colour monitors. Graphic User Interface used lot of True Type Fonts (TTF) similar to traditional printing press. Thus computer screen started acting as a “virtual printed paper.” Computers helped to create, store and distribute scientific journal articles, books and other documents. Thus computer started acting either as DCPD or DCCD.
Advancement in wireless transmission helped to build mobile telephone network. Second generation mobile standards like Global Systems for Mobile (GSM), Interim Standards-95 (IS-95) used digital modulation techniques. It means output of mobile phones were essentially digital data. In cellular phones speech is converted into digital data and fed into vocoder. They process the data and extract information required for speech synthesis at the receiver side. This information is sent at a rate of 13 Kbps. In the receiver speech is reconstructed from the transmitted information. Thus huge amount of digital content is produced and consumed by cell phones. 140 character length Simple Messaging Service (SMS) poured their share into digital world. In a span of 20 years 20 billion messages are distributed through out the world.
Earlier typed formal letters and telegrams were the main sources of official communication. Handwritten letters and telephone conversation were the main sources of personal communication. Digital technology introduced email and SMS and were used for personal as well as for official communication.
Almost all digital devices use some sort of display unit. As long as digital society prevails need for display will be on demand. As long as display devices prevails need for digital image processing will be on the demand. Digital society has very wide ramifications. Bringing in all the relevant details in one article and trying to make the article concise and crisp is a real challenge.
Note
In the earlier post it was stated that in the forthcoming post analog entertainment devices like cassette player, video player will be discussed in detail. Due to unforeseen (?) reasons it did not materialize. Clock has played vital role in rise of civilization. To commemorate Digital clock is displayed as representative digital device.
Source
[1]. Mark Elsom-Cook, Principles of Interactive Multimedia, Tata McGraw-Hill, New Delhi, 2004. (Wonderful book. Please devote some time and read the book.)
