A9-UNDERSTANDING SOFTWARE -1

 By  Pragyansharma  Polavarapu

(1)

 Decades back I often  felt  perplexed  to understand  how the simple commands  typed on the key board of a computer , a silent machine here on earth  , can  initiate  truly big actions in  faraway orbiting satellites.

The computer is  not a big roaring   machine  like a tractor or bulldozer but can  in fraction of a second  make  faraway  giant machines , through a coded  wireless signal, to  start some big actions . The  little computer on the table in front of  the engineer  has connection to  the computerized sensors of the faraway giant machines.  It is perhaps a  yes/no type technical session that goes on between them checking many  aspects of the faraway machine.

The  silent computer here before the engineer  can  give commands for  launching rockets ,  for building  a sky scrapper, for guiding an airplane in the sky, for helping detect  radiations from an atomic reactor , for accurately guiding the blasting of rocks while building  dams and  underwater power stations  etc. There are computerized sensors on the distant machines . Both  are interlinked through Client- Server type computer connections or through LAN  type networks.

 There  is also  a  networking joke  . The connection from X’s  phone to  the phone of a neighbor Y in the same  lane is suddenly broken. Then in an instant a new connection is  established by TCP/IP  through Japan-China-Singapore –Kolkata  digital  network  or even through  Antarctica .   

On to the screen of our  innocent looking desktop/laptop come old  Hindi and other  classic  cinemas,  videos  of   old tennis and cricket classic matches via the Internet . Soon the room becomes full of music and human voices when a video starts playing.  We see a  thrilling live session  of a cricket match  now being played . There are loud sounds and cheers. All this magic is done by the  algebra  like group of software instructions guiding the CPU  of the computer. The rules for writing perfect software programs  can be  created by senior  engineers and university professors.

(2)

The computer  seems  like a magician’s tool. Just as ,when  a  magician writes some words on a piece of paper and utters a “manthra”, a  magic action starts---   a mountain moves a few meters or  day changes into night or vivce versa. The computer’s ways are  similar to the ways of the magician .But the computers  are scientific things breathing mathematics (like humans  breathing oxygen ). They process  billions of 0s and 1s --- unending streams of digital strings like  0101010101 .

Every modern computer ---be it a desktop, laptop, tablet ,i-Pad or a  cell phone,digital camera  or a computer chip  based  modern machine like mixie/ washing machine /air-conditioner/ car /motorbike ---all these have  a intelligent micro-processor chip inside.  The  silicon chips have come to very wide use in such modern machines .We are quite in the  computer age .

The real  thing   is the “software”—a magic formula which makes computers thinking in digital way imitating human logic and self-driving  automatically .Hundreds or thousands of standardized “Logic circuits” devised by great electronic engineers and scientists decades ago exist in  a computer’s electronic  digital brain.

The  “electronic  logic circuits” are so fast and powerful that they can solve a million mathematical problems like ( 3x2),(3+2),(3-2),(3/2) etc  in millionth of a second!   The  transistor triodes create millions of electrical oscillationsin a second. Such oscillations divide a second into “millionth of second” units of time. The computer’s CPU  can create hundreds of  “time slices”  . In each such “time slice”  a separate computer  programme( like song, photo , English novel)can be processed . This giant capacity of modern computer is called “time sharing”. There are many such programming techniques.

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In old technology of transmitting photo and  sound signals by radio waves--- ( that created  commercial radio/commercial television/telephone networking)-- analogue signals were used .  The corresponding electrical wave for sound/picture signals was like an endless zig-zag line like the long  outline of an endless mountain range with highs and lows.

But in modern computer technology , the analog data signals  (whether of printed text/picture/sound and  audio/video files) are converted into  countless digital strings like 01010101 strings—with countless billions of 0s and 1s. Such data strings look  like a  train of billions of  wagons of rectangular shape and same height. Only such digitalized waves of  text/picture/sound can be processed by computer networking technologies like TCP/IP . The great wonder is that all are combined into a single digital stream . The speed of digital wave is 300,000 kilometers persecond. The triode creates millions of oscillations per second. And a second’s time is cut into a million pieces to create several perfect “time slices”. All so wonderful like a magician’s work.

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The  computer’s logic circuits are low voltage electric(electronic) circuits. They use the speed of  flow of electrons( the speed of flow of electric impulse) to solve mathematics-based  computer logic in millionth of second.

 We may note that computer treats all actions as so much mathematics processed in 01010101 language . Computer divides a file (say an English essay) into standard sized DATA PACKETS  with a destination address code—just like a sealed railway parcel with destination address. TCP/IP  does not care about meaning and content and treats every file transmitted on digital network as a set of sealed DATA PACKETS  with  destination address labels.

Roughly speaking, a data packets in TCP/IP contains digital data equal to a page of 500 to 1500 “computer words” called “bytes”. Each byte has eight or ten binary digits (0s and 1s)

Even the music/ moving picture (audio/video signals ) are converted into digital data packets. All these data packets  with destination address codes  created in millionth of a second  are pushed into the computer highways of internet .

(3)

 Simple people  not familiar with the inner working of the computer machine  feel awed and confused . They do not know   how computer gets such power with simple typing of a “software program” --(a set of coded  working steps just as in an algebra problem )-- on the key board of computer or  by  clicking the  icon in the active window  with  mouse button    .

In  one word we can say the power comes to computer when we give commands  to its digital brain through “SOFTWARE INSTRUCTIONS “ in a “SOFTWARE PROGRAM”.

What  really is a SOFTWARE PROGRAM? The way of thinking in computer’s brain closely resembles human thinking. This is not surprising because it is only human engineers who created rules for computer’s  thinking processes.

 (a) In the beginning computer was developed purely as a mathematical calculating machine. .  The  first electronic  calculators like ENIAC and EDVAC --(which  even 70-80 years ago could do tough mathematical calculations  in millionth of second  )---were  giant size  machines requiring a big air conditioned hall . The currents used were however only of low voltages like 2v,3v,5v,8v  as the diodes and triodes  would not function well at high voltages.

(b) In the ancient giant size computers/calculators  of 1940s , the  communication with  the giant’s   digital brain   was only  of one way type . Human engineer sent in numerical data to the giant calculator’s digital brain (CPU).

(3) The communication was only by switching circuits as in a big electrical switching unit . There was no interactive conversation with the machine . The computer’s reactions were indicated by  blinking of low illumination light bulbs and readings in the voltmeters and ammeters and some beep-beep sounds. 

(4)Though big  mathematical problems  were solved in  millionth of second , the  answers  to come out on paper tape   required  one or two days of waiting!  The hundred customers who brought their bundles of program cards had to wait for hours to load their data in stages through smaller electric typewriters/ photo-electric machines etc . The answers too came out in serial order. Thus “BATCH PROCESSING” was  a silent process. The  computer was  a silent moody giant not permitting anybody to come near except senior most engineers  to operate  its logic circuits. Decades passed like this.

(4)

Then truly a technical wonder happened,of course taking  a few decades  more to take concrete shape and become useful. It happened mainly in technical universities of US  and Europe about 70-80 years ago. The sand grain- sized   “crystal diode” and  the “transistor  triode” were  invented  and almost entirely replaced the 10,000 -15,000 hot glass bulbs (thermionic tubes) of  the giant  calculators.

Slowly the entire size of computer-calculator became reduced and a  new computer was born. After much experimentation and research these machines were standardized by engineers and scientists at universities.

Here we have to clearly realize  some basic rules of  computer. These rules apply  even to   most modern computers  of the 2020s and also to the  “digital phones” which technically come under category of networked computers.  

(a)Any electronic computer/calculator  is  an electrical machine  based mainly on mathematical logic .

(b) The radio technology/ telephone technology/ car technology/ airplane technology /medical technology /art technology etc—all such technologies of the  different computer-based machines are coveyed to the central controlling computer (the SERVER) through sensors.

(5)

 “Software program” closely resemble  the working steps of a  tough algebra problem  and comprises of several  perfectly constructed  “software instructions”. They are  just like the working steps of algebra problem .  Each “software instruction”  contains  one or two  “RESERVED WORDS”. 

 The RESERVED WORDS  are actually a powerful combination of several electric/electronic switches . When typed  on the computer keyboard these “RESERVED WORDS” activate   complicated electric/electronic circuits( of very low voltage electricity).They can start movement of vast data. The actions of RESERVED WORDS  are  like  actions of big trucks carrying heavy parcels from/to a parcel office . Some actions of RESERVED WORDS  are as follows.

 (a)Data is moved from/to  MAIN MEMORY/REGISTERS /ALU etc  

 ( b) Action may be taken to open/close/edit /delete FILES

(c) Bring data into computer or take out data from computer to the monitor screen/magnetic tape( in some old computers)as per commands of CPU.

 Thus RESERVED WORDS  are like heavy duty trucks of a parcel office in some of their data moving actions.

(6)

The logic/reasoning inside computer’s electronic brain  resembles  human logic—the human thinking in every day life. The “IAS model” of computer,the world’s standard model architecture for a digital computer ,proves this. (The computer works on  very low voltages of less than 10 volts like 2v,3v,5v,8v etc).

We have  concept of  “files” and “folders”. These are contained in the  “SECONDARY MEMORY”  ( in the  Data Drives like D,E,F drives ) .  The “files” and “folders” are similar to  the paper note books  we use for writing or the printed books which are “read only” type. The colossal data  (text/photo/music/ audio/video) is stored  in digital form i.e. billions of 0s and 1s  in the  disc drives . The data  can be brought on to computer screen and can be subjected to operations like READ/ WRITE /EDIT . 

Only after tiny TRANSISTORS ( one millimeter dimension “doped  semiconductor crystals” )came into wide use,  the high precision technologies of  transistor memory ,printed circuit boards, integrated circuits ,SSI,LSI , VLSI were developed.

Prior to that ,during the period 1950s to 1970s,in the  old computers, the “MEMORY”( i.e. recording area) was created with very small magnetized metal rings. The metal rings were fixed in a grid like system of horizontal and vertical hair thin  metal wire connections. Even big super computers used magnetic memories .   The  rings were  interlinked with hair thin metal lines and arranged in rows and columns to record data.

After  the most advanced and wonderful VLSI  technology appeared ,  tens of millions of   “transistors” were created in a single silicon crystals of the size of a shirt button! Such VLSI silicon  wafers were  created  by a  costly computer-controlled process .

 Microprocessor circuits were (to say in a simple words )etched inside the silicon wafer  by  computer controlled physical and chemical processes.  These tiny chips can  contain colossal quantities of data . For example, the  bulky Tolstoy novel “War and Peace” can be recorded in the small silicon chip!

(7)

 In the IAS type organization of electronic computer ,there are  small sized  memory  units  called REGISTERS. They are like  highly skilled office assistants  with special skills which can do their work (data manipulation ) in  millionth –of- second time units.  They handle both incoming data and outgoing data. In them data is detained for a brief millionth of second and sent to next REGISTER /ALU( mathematics  processor) /MAIN MEMORY.

The inner data processing and mathematical logic  parts inside  computer  are all controlled by CPU the electronic commander-in –chief inside  computer .The CPU  in turn is controlled by the human operator outside .

The  part called “MAIN MEMORY”   is exactly  like a class room black board where the teacher writes all working steps  to solve an algebra problem.  SOFTWARE INSTRUCTIONS of a  SOFTWARE PROGRAM  are  typed on the “MAIN MEMORY” BOARD just as   working steps of an algebra problem  are written by teacher on the black board.

(8)

In a systematic classical way ,after a software program is created on paper ,a   FLOW CHART and  the ALGORITHM( accurately constructed software instructions )  are prepared .

Flow chart is like an engineering  diagram and algorithm is the actual software program written on paper with most accurately constructed software instructions. The software program  snould be  written only in a IEEE approved   SOFTWARE LANGUAGE. 

  The software program should be typed  most accurately  on the key board . Even if there is slightest mistake like an extra comma the CPU  generates an automatic ERROR MESSAGE  and the computer stops working.

 

The software program is directly typed on keyboard of computer. Inside the computer the software program is converted by a TRANSLATOR SOFTWARE  to the 01010101 machine code instantly! The CPU and other logic parts(thinking parts) inside computer can understand only the 01010101 code. 

Some   model software programs are kept loaded within computer by manufacturers  as “LIBRARY FUNCTIONS” to help do the work at extreme speed.

Nowadays GUI  type  procedures are also loaded by manufacturers . They are created by a new type of software languages.  little pictures called ICONS operated through the COMPUTER MOUSE guide the actions of human operator.

We may note that (1) the logic processes  in a  computer are just like the common sense daily thinking processes in human society(2) it  is only the  software program that orders the CPU  to solve a problem.