The document outlines the evolution of computer hardware from the first generation of vacuum tubes (1946-1956) to the fourth generation of very large-scale integrated circuits (1980-present). It details the technological advancements and characteristics of each generation, including improvements in speed, memory capacity, and processing capabilities. Additionally, the text categorizes contemporary computers based on size and processing speed into mainframes, minicomputers, personal computers, workstations, and supercomputers.

1. Reporter: LOLITA D. DE LEON
THE EVOLUTION OF COMPUTER
HARDWARE

2. GENERATIONS OF COMPUTER
HARDWARE
The first and second
generations of computer
hardware were based on vacuum
tube and transistor technology.
The third and fourth generations
were based on semiconductor
technology

3. First Generation: Vacuum Tube
Technology, 1946-1956
Relied on vacuum
tubes to store and
process information
Consumed a great
deal of power, were
short-lived, and
generated a great
deal of heat

4. Extremely limited memory and processing
capability and were used for very limited
scientific and engineering work.
Maximum main memory size was
approximately 2000 bytes (2 kilobytes), with
a speed of 10 kilo instructions per second.
Rotating magnetic drums were used for
internal storage and punched cards for
external storage.

5. Second Generation: Transistors,
1957-1963
Transistors replaced
vacuum tubes as the
devices for storing
and processing
information.
Much more stable
and reliable than
vacuum tubes, they
generated less
heat, and they
consumed less power.

7. • Each transistor had to be individually
made and wired into a printed circuit
board – a slow, tedious process.
• Magnetic core memory was the primary
storage technology of this period.
• This system had to be assembled by hand
and, therefore, was very expensive.
• 32 kilobytes of RAM memory and speeds
reaching 200,000 to 300,000 instructions
per second.

8. Third Generation: Integrated Circuit,
1964-1979

9. Relied on integrated
circuits, which were made
by printing hundreds and
later thousands of tiny
transistors on small silicon
chips – semiconductors.
Memories expanded to 2
megabytes of RAM
memory, and speeds
accelerated to 5 MIPS.

10. FOURTH GENERATION: VERY LARGE-
SCALE INTEGRATED CIRCUITS,
1980-PRESENT
Use very large-scale integrated circuits (VLSIC),
which are packed with hundreds of thousands
and even millions of circuits per chip.

11. Costs have fallen to the point where desktop
computers are inexpensive and widely
available for use in business and everyday
life.
Computer memory sizes have mushroomed
to over 2 gigabytes in large commercial
machines; processing speeds have
exceeded 200 MIPS.
VLSIC technology has fueled a growing
movement toward microminiaturization – the
proliferation of computers that are so small,
fast, and cheap that they have become
ubiquitous.

13. What is a Microprocessor?
What is a Chip?
Very large-scale integrated circuit
technology, with hundreds of
thousands (or even millions) of
transistors on a single chip,
integrates the computer’s
memory, logic and control on a
single chip; hence the name
microprocessor, or computer on a
chip.

14. Chips are measured in several ways:
1. Word length – the number of bits can
be processed at one time by a
computer.
An 8-bit chip can process 8 bits, or 1
byte, of information in a single
machine cycle. A 32-bit chip can
process 32 bits or 4 bytes in a single
cycle. The larger the word length, the
greater the speed of the computer.

15. 2. A second factor affecting chip speed
is cycle speed.
Megahertz – a measure of cycle speed,
or the pacing of events in a computer;
one megahertz (MHz) equals one
million cycles per second.
3. A third factor affecting speed is the
data bus width – the number of bits
that can be moved at one time
between the CPU, primary storage,
and the other devices of a computer.

16. Obviously, to get a computer to
execute more instructions per
second and work through
programs or handle users
expeditiously, it is necessary to
increase the word length of the
processor, the data bus width, or
the cycle speed – or all three.

17. Reduced Instruction Set Computing
(RISC) – technology used to enhance
the speed of microprocessors by
embedding only the most frequently
used instructions on a chip.
Reduced instruction set (RISC)
computers have only the most
frequently used instructions embedded
in them. A RISC CPU can execute
most instructions in a single machine
cycle and sometimes multiple
instructions at the same most time.

18. RISC is most appropriate for scientific
and workstation computing, in which
repetitive arithmetic and logical
operations on data or applications
calling for three-dimensional image
rendering occur.
Programs written for conventional
processors cannot automatically be
transferred to RISC machines; new
software is required.

19. CATEGORIES OF
COMPUTER
We can use size and
processing speed to
categorize
contemporary
computers as
mainframes,
minicomputers, PCs,
workstations, and
supercomputers.

20. MAINFRAME – is the largest
computer, a powerhouse with
massive memory and extremely
rapid processing power. It is used
for very large business, scientific, or
military applications in which a
computer must handle massive
amounts of data or many
complicated processes.

22. MINIFRAME – is a mid-range computer,
about the size of an office desk, often
used in universities, factories, or
research laboratories.
PERSONAL COMPUTER (PC) – sometimes
referred to as a microcomputer, is one
that can be placed on a desktop or
carried from room to room. PCs are
used for personal and business
applications.

23. WORKSTATION – also fits on a
desktop but has more powerful
mathematical and graphics
processing capability than a PC
and can perform more
complicated tasks at the same
time than a PC. Workstations are
used for scientific, engineering,
and design work that requires
powerful graphics or
computational capabilities.

24. SUPERCOMPUTER –is a highly
sophisticated and powerful machine
used for tasks requiring extremely rapid
and complex calculations with
hundreds of thousands of variable
factors.
Supercomputer have traditionally
been used in scientific and military
work, but they are also starting to be
used in business.

26. Problem with this classification scheme:
A PC today has the computing power of a
mainframe from the 1980s or the
minicomputer of a few years ago.
Powerful PCs have sophisticated graphics and
processing capabilities similar to workstations.
PCs still cannot performs as many tasks at
once as mainframes, minicomputers or
workstations; nor can they be used by as
many people simultaneously as these larger
machines.
In another decade, some PCs might have the
power and processing speed of today’s
supercomputers.

27. SERVER COMPUTERS –
are specifically
optimized for
network use, with
large memory and
disk storage
capacity, high-
speed
communications
capabilities, and
powerful CPUs.

28. Distributed Processing – the
distribution of computer
processing work among multiple
computers linked by a
communication network.
Centralized Processing – processing
that is accomplished by one large
central computer.

29. DOWNSIZING – the process of
transferring applications from
large computers to smaller ones.
Cooperative Processing – type of
processing that divides the
processing work for transaction –
based applications among
mainframes and PCs.

30. MAINFRAME TASKS PC TASKS
File input/output User interface/screen
presentation
 Help screens
Editing data fields
Cross-field editing
Error processing
Calculations
COOPERATIVE PROCESSING

31. PARALLEL PROCESSING – type of
processing in which more than one
instruction can be processed at a time
by breaking down problems into
smaller parts and processing them
simultaneously with multiple
processors.
SEQUENTIAL PROCESSING – each task is
assigned to one CPU that processes
one instruction at a time.

32. SEQUENTIAL PARALLEL PROCESSING
PROCESSING
Program
Program
Task 1
CPU
CPU CPU CPU CPU CPU
Result Task 1 Task 2 Task 3 Task 4 Task 5
Program
Task 2 RESULT
CPU
Result