A4-THE IAS COMPUTER-1

 

By pragyansharma polavarapu

 

The  IAS computer -- ( a  model plan for creation of standard working parts inside computer and related software organization inside computer)--was developed in 1952 by the engineers at the Institute of Advanced Studies (IAS) ,Princeton, USA  under supervision of famed mathematics professor Dr Jan von Neumann. This technologically  sophisticated  model  had a  revolutionary impact on the  computer industry and computer researchers and engineers . The IAS  design can be  treated as  one of the greatest advances in computer science that helped create the modern wonder called computer.

 The engineering plan (“the software  and corresponding hadware architecture”) of the  IAS  machine greatly helped in the  development of modern  desktop personal computers(the micros) which are now  sold in hundreds of millions  .This  engineering plan is  famous as “von Neumann  architecture”. Dr Jan von Neumann a Hungarian-American  physicist  is considered as one of the greatest mathematician of 20th century.

It may be noted that  this  model  was developed  in the times when about 15,000 hot cathode glass diodes and triodes were used to create the first electronic calculating machines later called computers . The IAS  architecture was invented  decades before the sand grain size transistors were created out of semiconductor materials.The size of computer was suddenly and surprisingly got greatly reduced.

Later came the  “SILICON CHIP” containing “INTEGRATED CIRCUITS”. To say in simple terms ,most complex computer circuits are etched within a single silicon chip  by a very complex and costly technological process (costing billions of dollars). Inside the silicon chip hundreds of thousands of tiny transistors were linked  logic circuits,mathematical circuits and also data storing memory organizations.

We should remember that it was only a few decades later that transistors entirely replaced the big thermionic tubes inside the standard IAS model. . As already stated the first IAS  model computers were of very large size containing about 15000 large electric bulb size thermionic valves. The thermionic valves also could  switch on/switch off tiny current voltages millions of times per second . The first thermionic tube computers were simple mathematical calculators (of colossal size) which could perform millions of mathematical calculations in millionth of second.

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We should clearly understand the meaning of the term  “software program”. The software program  is nothing but a  group of “working steps”  very much like the working steps we write to solve an algebra problem .  The software program is  the set of very accurate commands to the CPU  the central controlling part of computer. They are written in a strict software language  in a strict mathematical and English code . The instructions are typed by the human programmer outside onto the MAIN MEMORY  through the key board (or equivalent input device).The “software instructions ”  are  like the steps we write to solve a tough  alzebra problem. Each software instruction  also resembles an abrupt  military code.

Inside the computer’s electronic brain a special TRANSLATOR  software  also exists. It instantly translates  each line of the program (each software instruction)  into the computer’s  01010101 machine language. The machine language is like an endless string of millions of only the two symbols 0 and 1. They are not the mathematical 0 and 1 but electrical voltage symbols.

We have to note another thing. The human engineer sitting at the key board is always the commander. Though the CPU is the “commander- in- chief inside the computer” it is only a slave  obeying  the commands of the human engineer . Only the  machine language code appears  on the MAIN MEMORY  which is  almost entirely  for the exclusive use of the CPU.  Only the internationally standardized “SOFTWARE LANGUAGES ” , licensed by the  INTERNATIONAL INSTITUTE OF ELECTRICAL AND ELECTRONIC ENGINEERS (IEEE), are used to compose the “SOFTWARE INSTRUCTIONS” in the software  program.