B. Pharmacy

Introduction:

Computer is defined as an electronic digital and automatic machine which works on two state of current which is On and Off where on is represented by 1 and off is represented by 0. It takes input from user, process it, store it if necessary and give output in our desire form. It generates information by processing raw data according to the described sequence of instruction given by the user or operator. It is also called a multipurpose, programmable, electronic data processing device.

Evolution of Computer

"Necessity is the mother of invention". The saying is true for computer also because computer were inbuilt as a result of man search for fast and accurate calculating device. It is due to the need and curiosity of man for faster way to calculate has led to develop a computer. Following are the major development in the history of computer from early calculating machine to modern high speed digital computer.

The Mechanical Era (Zeroth Generation)

A mechanical computer is built from mechanical components such as levers and gears, rather than electronic components. The most common examples are adding machines and mechanical counters, which use the turning of gears to increment output displays. More complex examples can carry out multiplication and division, and even differential analysis.

1. ABACUS:

The abacus, also called a counting frame, is a calculating tool used primarily in parts of Asia for performing arithmetic processes during 5000 BC to 3000 BC. Today, abaci are often constructed as a bamboo frame with beads sliding on wires, but originally they were beans or stones moved in grooves in sand or on tablets of wood, stone, or metal. It has two parts, heaven and earth. The heaven consists of two beads, whereas the earth part consists of five beads to each rod. It could perform only addition and subtraction.

2. John Napier and his rods (1550-1617 AD):

The Scottish mathematician John Napier first published the table of logarithms in 1614 AD and it was very useful in simplifying the multiplication of large numbers. He invented some bone rods, uses bones to demonstrate division by subtraction and multiplication by addition, according to principle of logarithm. These rods were made up of strips of bones on which numbers were carved and painted, that device was called Napier bone.

3. William Oughtred and his Slide Rule (1575-1660 AD):

In 1620 AD, the English man William Oughtred invented a rectangular calculating device called slide-rule based on the principles of logarithm. It consists of two graduated scales, one of which slips upon the other. The scales are devised in such a manner that suitable alignment of one scale against the other makes it possible to find products and quotient of any numbers.

4. Blaise Pascal and his calculator (1623-1662 AD):

A French mathematician Blaise Pascal developed mechanical calculating machine to assist his father in his accounting work. In this machine numbers were entered by dialing a series of numbered wheels each wheel having numbers from 0 to 9. For addition the wheel was moved into forward direction and for subtraction into the reverse direction. It could perform addition and subtraction up to 8 digits. This mechanical calculator is called Pascaline.

5. Baron Gottfried Wilhelm Von Leibniz and his Stepped Reckoner (1646-1716):

In 1671 AD, Leibniz modified the Pascaline machine and invented a first calculator Stepped Reckoner, which was able to perform automatic addition, subtraction, multiplication, division and could find out square root. Leibniz's machine used stepped cylinder each with nine teeth of varying lengths instead of wheels. It was called Leibniz-calculator or Stepped Reckoner.

6. Joseph Marie Jacquard and his Jacquard loom and punch cards (1752-1834 AD):

The French textile manufacturer Joseph Marie Jacquard invented a mechanism for automated weaving cloths for the textile industry at Lyon in 1802 AD. This machine was used to automatically control weaving looms to facilitate the production of weaving cloth with complex patterns. This machine was controlled by punch-cards i.e. principle of present and absence of holes.

7. Charles Babbage and his analytical engine (1791-1871 AD):

The English professor and mathematician Charles Babbage invented the Difference Engine at Cambridge University in 1822 AD. Theoretically, it can solve differential equations and calculate various mathematical function, logarithmic tables, polynomial and trigonometric functions. Later Babbage continued working on his difference Engine and developed new idea for constructing general purpose, fully programmable automated machine called Analytical Engine in 1833 AD. He invented the working principle of computers on which the modern computer was based.

8. Lady Augusta Ada Byron Lovelace (1815-1852 AD):

The English woman Lady Augusta created the instruction routines to be fed into the computer and she suggested to Charles Babbage writing a plan for how the engine might calculate using Bernoulli numbers and that plan is now regarded as the first computer program. She wrote the program for Babbage analytical engine so she was considered the first computer programmer and, a software language developed by the US Defense Department was named Ada in her honor in 1979 AD.

9. George Boole and his Boolean algebra (1815-1864 AD):

The Irish mathematician George Boole developed a method of reducing statements of logic to algebraic statements, using a simple set of symbols. He interprets that algebraic statements in to Boolean algebra in terms of truth values, called the propositional calculus, form the basis of the digital processes in modern computers. His logic provides the basic idea of presenting the electronic circuits with binary input (0 or 1) and its output.

10. Herman Hollerith and his tabulating machine (1860-1929 AD):

An American inventor Herman Hollerith also applied the Jacquard loom concept in computing and applies for patents for automatic punch-card tabulating machine in 1884 AD. He invented a machine known as tabulating Machine (TM) in 1886 AD. He used cards to store data and each punch on a card represented one number and combinations of punches represented a letter. 80 variables could be stored on a single card. His machine was first used to compute the U.S. census. Later his machine became International Business Machine (IBM). He was founder of IBM and founded in 1924 AD. in USA.

The Electro-Mechanical Era

1. Mark-I:

A professor of Physics Howard H. Aiken designed a general purpose mechanical computer at Harvard University and IBM, while working on his doctorate in physics, in the year 1937 and the machine was called IBM Automatic Sequence Controlled Calculator (IBM ASCC) and later as Harvard Mark-I. It was relay based computer on the based on the concept of Charles Babbage's analytical engine principle. Later he modified Mark-I and made Mark-II by using 19000 valves.

Features of Mark-I

• It used about 18 thousand vacuum tubes as main memory device with seven lakhs 50 thousands parts.
• It is about 51 feet long, 8 feet height and 3 feet wide i.e. bulky in size.
• Technically, it was very complicated machine, consumed huge amount of power and generated lot of heat during the operation.
• The time taken for multiplication was about four seconds and for division was about eleven seconds.
• The results were printed at the rate of one result per five seconds.

2. ABC (Atanasoff Berry Computer):

In 1938 John J. Atanasoff and Clifford Berry designed ABC for solving systems of simultaneous equation. It used 18000 calves and other 45 valves for internal logic and capacitors for storage of electrical charges. It used punched cards as secondary storage.

3. John Von Neumann (1903-1957 AD):

The Hungarian mathematician Jon von Neumann gave the idea of stored program computer in the sense that program is stored internally in the main memory of the computer along with its associated data in 1945. Therefore, he is called father of stored program. Before that, modification of a program was not possible.

The electronic computers Era

1. ENIAC (Electronic Numerical Integrator and Calculator):

In 1946, John W. Mauchly and J. Prosper Eckert developed ENIAC at Pennsylvania, USA. ENIAC was the first-popular general-purpose electronic digital computer. It was very large machine weighing about 30 tons and containing about 17468 vacuum tubes, 70,000 resisters, 5 million soldered joins and it consumed 160 kilowatts. It took 200 microseconds for addition and 3 milliseconds to perform a 10-digit multiplication. It was first and last computer, which used decimal number system instead of binary system.

2. EDSAC (Electronic Delay Storage Automatic Computer):

Maurice Wilkes invented EDSAC in 1949. It also used vacuum tubes. Although started after EDVAC, it was completed before EDVAC. Therefore, it became the first stored program computer.

3. EDVAC (Electronic Discrete Variable Automatic Computer):

It was developed by J.P. Eckert and J. Mauchly in 1952 and used for more school personnel and the Ballistics Research Laboratory of the USA Army, built a computer named EDVAC. John Von Neumann supervised the construction of EDVAC. It also used vacuum tubes and some internal storage.

4. UNIVAC (Universal Automatic Computer):

J.P. Eckert and J. Mauchly developed it in 1961. It was the first computer manufactured for commercial use and general-purpose digital computer. Before this, all the computers were used for either defense or census.

What computers can do and cannot do

Capabilities:

• Computer produces 100% accurate outputs, if correct data and instructions are provided.
• It is faster in calculation than human.
• It can perform complicated and difficult work at a high speed.
• It is capable of permanently storing data and retrieving it whenever required.
• It can perform repeated task with the same speed and accuracy.

Limitations:

• Computer is non-intelligent (dull) machine. It cannot think and give the right decisions as human being.
• It cannot operate without battery or electricity.
• Failure in devices and wrong information by users make it unreliable.
• It cannot memorize and recall, as needed only store data in secondary memory.
• It requires instructions to perform a task.

IPO Cycle:

During the functioning of a computer, the first stage (things to work upon) is called input stage, the second stage (the actual work being performed) is called process stage and the third stage (the result) is called output stage. Certain input is needed to accomplish a task; a process is carried out on the input to obtain the output.

Every task follows this Input-Process-Output cycle (IPO cycle in short). A computer follows the I-P-O cycle that is; it needs certain input, carries out a process and produces the output.

Generation of computers:

Generation in computer is a step in technology. It provides a framework for the growth of the computer industry. The generations are considered based on architecture, languages, modes of operation etc. There have been great variations in size and cost of computer. Computer system belonging to one particular technological class is said to belong to a particular computer generation.

Generation (Period)	Key hardware technologies	Key software technologies	Key characteristics	Some representative systems
First (1942-1955)	· Vacuum tubes · Electromagnetic relay memory · Punched cards secondary storage	· Machine and assembly languages · Stored program concept · Mostly scientific applications	· Bulky in size · High unreliable · Limited commercial use and costly · Difficult commercial production · Difficult to use	· ENIAC · EDVAC · EDSAC · UNIVAC I · IBM 701
Second (1955-1964)	· Transistors · Magnetic cores memory · Magnetic tapes · Disks for secondary storage	· Batch operating system · High-level programming languages · Scientific and commercial applications	· Faster, smaller, more reliable and easier to program than previous generation systems · Commercial production was still difficult and costly	· Honeywell 400 · IBM 7030 · CDC 1604 · UNIVAC LARC
Third (1964-1975)	· ICs with SSI and MSI technologies · Larger magnetic cores memory · Larger capacity disks and magnetic tapes secondary storage · Minicomputer; upward compatible family of computers	· Timesharing operating system · Standardization of high-level programming languages · Unbundling of software from hardware	· Faster, smaller, more reliable, easier and cheaper to produce · Commercially easier to use and easier to upgrade than previous generation systems · Scientific, commercial and interactive on-line applications	· IBM 360/370 · PDP-8 · PDP-11 · CDC 6600
Fourth (1975-1989)	· ICs and VLSI technology · Microprocessors; semiconductor memory · Larger capacity hard disks as in-build secondary storage · Magnetic tapes and floppy disks as portable storage media · Personal computers · Supercomputers based on parallel vector processing and symmetric multiprocessing technologies · Spread of high speed computer networks	· Operating systems for PCs with GUI and multiple windows on a single terminal screen · Multiprocessing OS with concurrent programming languages · UNIX operating system · C and C++ programming language · PC, Network-based, and supercomputing applications · Object-oriented design and programming	· Small, affordable, reliable and easy to use PCs · More powerful and reliable mainframe systems and supercomputers · Totally general purpose machines · Easier to produce commercially · Easier to upgrade · Rapid software development possible	· IBM PC and its clones · Apple II · TRS-80 · VAX 9000 · CRAY-1 · CRAY-2 · CRAY-X/MP
Fifth (1989-present)	· ICs and ULSI technology · Larger capacity main memory, hard disks with RAID support · Optical disks as portable read-only storage media · Notebooks, powerful desktop PCs and workstations · Powerful servers, supercomputers · Internet · Cluster computing	· World wide web · Multimedia, Internet applications · Micro-kernel, multithreading, multicore OS · JAVA · MPI and PVM libraries for parallel programming	· Portable computers · Powerful, cheaper, reliable and easier to use desktop machines · Very powerful mainframes · High uptime due to hot-pluggable components · General purpose machines · Easier to produce commercially	· IBM notebooks · Pentium PCs · SUN workstations · IBM SP/2 · SGI Origin 2000 · PARAM supercomputers