The document provides an overview of computers, including their definition, generations, history, applications, characteristics, limitations, and classifications. It discusses how computers have evolved from early machines using vacuum tubes to today's microprocessors. Computers are electronic devices that can process and store information, and are classified based on their purpose, type of data handled, and processing capacity.

1. LECTURE 1 - Fundamentals of Computer
Computer Defined
 An electronic device designated to manipulate useful information
 An electronic device, operating under the control of instructions stored in its own memory
unit, that can accept data, process data arithmetically and logically, produce output from the
processing, and store the results for future use
Generations of Computers
First Generation (1952 – 1958)
 Awesome in size
 Controlled by thousands of vacuum tubes or valves
 Consumes great amount of power that often resulted in overheating and failure
 The operators cannot recognize whether the breakdown was in the programming or in the
machine
 Information were stored on punched cards as well as on magnetic tapes
The language level used was machine language which used numbers
Second Generation Computer (1959-1964)
 Development of assembly or symbolic language
 Development of high level language such as Fortran (1954) and Cobol (1959) allowed
programmers to give more attention to solving problems
 Uses transistors (used less power and did not get so hot quickly)
Third Generation Computers (1965-1970)
 Uses Integrated Circuit, commonly known as the silicon chip, which revolutionized
electronic
 If later progressed to Large Scale Integration (LSI), where few chips could replace several
hundred thousands of transistors
Fourth Generation Computer (1971-present)
 Uses microprocessor, a chip which contains all the main electronic components of a
compound

2.  If made possible to build computers to enormous logical capacity and reliability, more
cheaply and in a very small space
 Very Large Space Integration (VLSI) was achieved
 Microprocessors led to the development of microcomputers
History of Computers
 500 BC – the Chinese invented the Abacus, considered to be the first computer device,
which can perform simple addition and subtraction operations.
 1617 – John Napier, a Scottish mathematician, invented the NAPIER’S Bone – a table of
logarithms made of ivory
 1630 – William Oughtred, an English mathematician, invented the SLIDE RULE, a device
made of wood with movable scales arrange to slide opposite each other
 1642 – Blaise Pascal, a French mathematician, invented the PASCALINE – the first
mechanical calculating machine
 1694 – Gottfried Wilhelm von Leibniz, a German mathematician. His machine, the LEIBNIZ
MACHINE, considered of a stepped cylinder that could perform the four fundamental
operations and square root.
 1801 – Joseph Marie Jacquard, a French weaver and designer, devised the JACQUARD LOOM
which used hole-punched cards. This machine wove variety of patterns
 1822 – Charles Babbage, an English mathematician and is known to be the “Father of
Modern Computer”, invented the DIFFERENCE MACHINE. This machine was capable of
computing mathematical tables and solves polynomial equation
 1833 – Charles Babbage also invented the ANALYTICAL MACHINE designed to perform
complex mathematical calculations. This was considered to be the first general purpose
computer
 1887 – Herman Hollerith, an American statistician and founder of Tabulating Machine
Company (now called International Business Machine or IBM) invented the CENSUS
MACHINE
 1892 – William Seward Burrough, an American inventor, designed a key-driven machine
that produced a hardcopy. This was called ADDING/CALCULATING MACHINE.
 1944 – Burrough invented the MARK 1 or ASCC (Automatic Sequence Controlled Calculator)
machine that contains more than 15,000 vacuum tubes some of which are 3 feet tall

3.  1945 – John Presper Eckert, Jr. and William Mauchly from the University of Pennsylvania
invented the ENIAC (Electronic Numerical Integrator and Computer) that had the capacity
of 5,000 computations per second
 1948 – The IBM developed a more different design than the ENIAC – the SSEC (Selective
Sequence Electronic Calculator)
 1950 – Eckert Jr. and Mauchly again developed a machine The UNIVAC 1 (Universal
Automatic Computer)which could perform 10,000 computations per second. The IBM again
developed a machine that could perform 100,000 computations per second and can store
data internally. The machine was the IBM 704
 1963 – Digital Equipment Corp. introduced the PDP-8, regarded as the first successful
minicomputer
 1977 – Two young computer enthusiasts, Steven Jobs and Steve Wozniak, collaborated to
create and build their Apple II computer on a makeshift production line in Job’s garage
 1981 – IBM introduced its hat into the personal computer ring with the announcement of
the IBM PC. It sold 35,000 on its first year of release.
Applications of Computers
 In the scientific and engineering fields, it provides inexpensive and accurate computation
for better designs of devices or machines and more discoveries made in less time
 In the business world, it is used in the preparation of payrolls, in recording accounts
receivables, in keeping tracks or inventions
 In banks, insurance companies, hospitals, and government offices, records are
computerized
 Large firms and offices such as PLDT, Meralco and MWSS prepare invoices with computers
 Provide instantaneous and accurate data for airlines, hotels and check-out counters in the
department stores
 Now becoming an everyday tool not only in the offices but in homes as well
Characteristics of Computer
It is a machine – can only do things for it was designed
It is electronic – runs on electrical energy through its electronic components
It is automatic – runs continuously once started
It can manipulate data – following specified instructions, it can perform arithmetic functions
and can compare data

4. It has memory – the ability to read instructions and store these
It has logic functions – can produce results after instructions were fed into it
Computer Limitations
 Dependence on prepared instructions
 Inability to derive meanings from objects
 Inability to generate information
 It cannot correct wrong instructions
Why Computers Sometimes Fail
 GIGO (Garbage In Garbage Out). Computer error may result from erroneously entered input.
 Programs contain errors or “bugs” that do not become evident until a specific set of
circumstances arises.
 “Users” do not understand each other’s needs or have not communicated successfully.
 Improper controls can lead to sabotage the company and invasion of privacy
 Lack of standard results in problems when an organization obtains new equipment, hires
new computer professionals, and attempts to provide some consistent set of procedures to
be adopted by its computing staff
 Manufacturer fails to supply needed spare parts, trained technicians, or that particular
machine model is no longer in production
Classification of Computers
Classification by purpose
 General-Purpose Computers - A computer that has the ability to store different programs of
instructions and thus to perform a variety of operations.
 Special-Purpose Computers - A computer designed to perform one specific task
Classification by Type of Data Handled
• Digital Computers – a machine that specialize in counting of items that are distinct from one
another, e.g. Text, integers, morse code
• Analog Computer – machine that deals with quantities that are continuous variable. This
means that no individual elements can be identified from any other element, e.g. Light,
voice, and video

5. • Hybrid Computers – machine that combines the measuring capabilities of the analog
computer and the logical and control capabilities of the digital computer
Classification of Computers Acc. to Capacity
 Microcomputers –capable of handling small, single-business applications such as sales
analysis, inventory, billing and payroll.
 Minicomputers – They can do operation like airline reservations
 Medium-size Computers – They can serve the needs of a university.
 Large Computers –They can be used in government agencies and in the development of
space technology
 Supercomputers – machines that have capabilities far beyond even the traditional large-
scale systems. They are essential for applications ranging from nuclear weapon
development to accurate weather forecasting.