Introduction to Computers and Programming. History of computers What is a computer system? What is a software? What is programming? Different languages Compiled vs. interpreted. History of Computers.
History of computers
What is a computer system?
What is a software?
What is programming?
Compiled vs. interpreted
Computers are programmable. The first calculators were not programmable, hence not considered computers.
Although many calculators today are programmable, we still distinguish them from computers. A better distinction between them might be the generality of their function – a computer is more a more general computing machine than a calculator.
However, where to draw the line is difficult. For our purposes, we will continue to use the (archaic) description that calculators are not programmable.
Babbage’s difference engine
Device to subtract adjacent valuesin a column of numbers. Created for engineers in charge of creating tables of logarithms and trigonometric functions.
‘Zsszbj zs 9599’ would be
‘Attack at 0600’
CPU + memory
1) Machine language – also
called binary language. Sequence
of 0’s and 1’s.
2) Assembly language – each line of code produces a single machine instruction (add, subtract…), see bottom of page 11.
3) High-level language – slightly closer to spoken languages.
a= a + b + c;
This line does the same as the two above.
The Internet is a set of computers which communicate using a set of communication protocols, or agreements, to achieve the desired goals.
Examples of Internet protocols (application layer):
The WWW is just one of many means of using the Internet