Computer Literacy and
Generations of Computers
Artificial Intelligence
Section 1
Mr. Sciame
What is a computer?
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Definition
Types
Programs/Programmers
Hardware
Computer Organization
• All computers may be envisioned as being
divided into 6 logical units:
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Input Unit
Output Unit
Memory Unit
Arithmetic/Logic Unit
Central Processing Unit
Secondary Storage
Historical Perspectives:
Early Mechanical Devices
• The Abacus, also called a counting frame, is a
calculating tool used primarily in parts of Asia for
performing arithmetic processes.
Historical Perspectives:
Early Mechanical Devices
Blaise Pascal was a 17th century philosopher,
mathematician, and inventor
The Pascal Adder
Blaise Pascal
The Difference Engine
• Created by Charles
Babbage, beginning in
1822.
• Ada Byron, the
“Countess of
Lovelace” aided him
by writing the
instructions (program)
for it
Charles Babbage and Ada Byron
The Hollerith Tabulating
Machine
• Hollerith’s Tabulating Machine was inspired by
Jacquard’s Loom Machine and Train Ticket
Punchers.
– The 1880 census took 7 years to complete. A contest
was held to find a better method. Hollerith’s Tabulating
Machine won the contest. The 1890 census took 6
months to complete.
– In 1890, Hollerith founded the Tabulating Machine
Company (TMC). In 1911, it merged with Computing
Scale Co. and International Time Recording to become
Computer Tabulating Recording Co (CTR). In 1924,
CTR became IBM.
Hollerith and His Machine
Early Electronic Computers
• Howard Aiken and Grace Hopper designed the
MARK series of computers at Harvard University.
• The MARK series of computers began with the
Mark I in 1944.
• Used by the US Navy for gunnery and ballistic
calculations, the Mark I was in operation until
1959.
Howard Aiken
• He was an electrical
engineer and physicist
who first conceived of the
Mark I in 1937. It was
completed in 1944.
• IBM funded his research.
Aiken headed a team of
three engineers including
Grace Hopper.
Grace Hopper
• Grace Hopper studied at
Vassar College and Yale
and then joined the Naval
Reserve in 1943
• She invented the language
APT and verified the
language COBOL.
– Grace Hopper was the first
computer science "Man of the
Year" in 1969.
• In 1991, Grace Hopper
received the National Medal
of Technology.
Notable Quotes
• Howard Aiken loved computers, but even he had
no idea of their eventual widespread appeal. "Only
six electronic digital computers would be required
to satisfy the computing needs of the entire United
States," he said in 1947.
• Grace Hopper is responsible for the term 'bug' for
a computer fault. The original 'bug' was a moth,
which caused a hardware fault in the Mark I.
Hopper was the first person to 'debug' a computer.
Historical Perspectives
• Early Mechanical Devices
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The Abacus
The Pascal Adder
The Difference Engine
The Hollerith Tabulating Machine
• Early Electronic Computers
– Mark I
– ABC
– ENIAC
The First Generation
• 1951-58
• Characteristics
– The UNIVAC
– Vacuum Tubes
– Binary (Machine Code)
Second Generation
• 1958-64
• Characteristics:
– Transistor replaces vacuum tube
– Introduction of Programming Languages
– Split between Business and Scientific Usage
Third Generation
• 1964-70
• Characteristics
– Integrated Circuits (Chips)
– Proliferation of Languages
Fourth Generation
• 1970 - 95
• Characteristics:
– PC
– Packaged Programs
Fifth Generation
• Today
• Characteristics:
– Internet
– Multimedia
– CD usage
Evolution of Operating Systems
1. Batch Processing
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One job at a time, a single program at a time,
processing data in groups or batches
2. Multiprogramming
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Sharing computers resources (efficiency)
“simultaneous” operation of many jobs. Computer
shares resources vying for attention.
3. Timesharing
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Computer accessed through terminals. Computer goes
from user to user, appearing to be simultaneous.
Evolution of Operating Systems
4. Personal Computing
– Standalone
5. Local Area Networks
– Computer networks linking pc’s to the
network
6. Distributed Computing
– Computing is no longer at one site, but
distributed elsewhere