Directs the computer’s hardware to perform work.

Distinguished from hardware by its conceptual rather than physical nature.

Consists of instructions communicated electronically to the hardware.

Consists of physical components.

1. Computers do not directly understand human language & software is needed to translate instructions created in human language into machine language.

Machine level computers can understand only binary numbers, not English or any other human language.

2. Packaged or stored software is needed to create their own software every time they needed to use the computer.

Writing software instructions (PROGRAMMING) is extremely difficult, time consuming, and for most people, tedious. It is much more practical and economical for one highly skilled person or programming team to develop programs that many other people can buy and use to do common tasks.

Software is supplied as organized instruction sets called “PROGRAMS” or more typically as a set of related programs called a “PACKAGE” make the computer an economical work tool.

Augusta Ada Byron, (1816-1852), a mathematician and co-researcher with Charles Babbage (1791-1871) first described the concept of a stored computer program.

Charles Babbage invented (but never built) a device that he named the “analytical machine”

Babbage’s son finally built his machine in 1910 but was never able to make it work reliably.

The concept of a machine that could perform mathematical functions stimulated the thinking of other scientists and mathematicians about how to build such a machine and how instructions could be communicated to the machine.

Countess Lovelace theorized the use of automatic repetitious arithmetic steps that the analytical engine would follow to solve a problem namely the “loop concept”. This concept gave her the title of the “first programmer” in computer history.

Robert Von Newmann (1888-1976) who proposed that both data and instructions could be stored in the computer and that the instructions could be automatically carried out.

Invention of a weaver from France, Joseph Jacquard.

Used blocks of wood with holes drilled in such a way that the threads to be woven into cloth could form a “program” or set of machine instructions to the loom.

In 1881, Herman Hollerith (1860-1929) used Jacquard’s idea but developed a machine that could read punched cards and tabulate the results.

In 1884, Hollerith patented his machine and punched card system. He’s ideas were successful that he formed a company called Tabulating Machine. Eventually after several changes of ownership and name changes the company became International Business Machine popularly known as IBM.

The punched card method of entering programs (software) and data into computers continued to exist until the late 1960s.

Some punched card use continued until around 1980.

After that time, keypunch machines and punch card readers were withdrawn from computer centers.

Born in New York in 1906. Obtained a degree of

mathematics and physics, Phi Beta Kappa from Vassar in 1928 and her PhD in mathematics in 1934.

In 1941, she offered her services to her country by enlisting in the U.S. Naval Reserve.

She was assigned to the Bureau of Ordinance Computation at Harvard University where she worked with the first digital computer, the Mark I, and its successor, the Mark II.

Rear Admiral Grace Murray Hopper

A remarkable woman known as “The Mother of

Computing”

Was perhaps the world’s most expert programmer of early computers.

In 1946, the navy returned Hopper to inactive duty, but recalled her to active duty in 1967 during the Vietnam War.

Her brilliance with computers was considered irreplaceable by the military and continued to serve her country until she retired the second time in 1986 at the age of 79.

Throughout her career she developed many concepts and mathematical foundations of computer programming science.

A major activity in program testing is debugging, which means checking the program to ensure that it is free of error. This term was coined by Grace Hopper.

In 1945, when working at Harvard on the Mark II computer her program crashed. She discovered that a moth caught in the machine had caused the crash. To correct the problem and get system working again she “debugged” the computer.

Admiral Hopper was widely known for her accomplishments in computer programming language and development and also for her extraordinary vision and wit.

Her work on programming languages in the early 1950s formed the foundation for the first truly English-like language, the Common Business-Oriented Language (COBOL).

COBOL was considered the first “universal” programming language and still used in business applications.

When the focus was on bigger rather than on more friendly computers, she quipped

“In pioneer days they used oxen for heavy pulling, and one ox couldn’t budge a log, they didn’t try to grow a larger ox.”

We shouldn’t be trying for bigger computer , but for more systems of computers.

She recognized that a better approach would be to have many computers working independently and together so that more work could be accomplished.

Today, the internet, network of networks, might be viewed as the realization of Grace Hopper’s early vision of computing.

“Life was simple before World War II. After that, we had systems.”