Classification of Computers, Purpose, Type, Efficiency, General purpose computers, Special purpose computer, Analogy Computers, Digital computers, hybrid computers, Micro computer, Mini computer, main frame computer, super computer

1. Classification of
Computer
By
Dr. I. Uma Maheswari,
Email id: iuma_maheswari@yahoo.co.in

2. Computers are classified according to the
 Purpose.
 Type.
 Efficiency

3. Classification according to the purpose.
 General Purpose Computers
 Special Purpose Computers

4. General Purpose Computers are
ordinary computers, which can be
used by everyone.
The user can choose the software he
wanted and use the computer for any
job.
Ordinary digital computers fall into this
category.

5. Classification of Computers according to their types:
 Analog Computers.
 Digital Computers
 Hybrid Computers.

6. Analog Computers
A computer that operates by measuring
continuously varying quantities like voltage
current is called an analog computer.
The computers are simple in their construction
and can be used to solve complex, time
dependent problems.

7.  In analog computers, the variable is electrical signal
system.
 Arithmetic operations are carried out electrical using
signal amplifier blocks.
 Graphical results are easily, directly and fastly taken
here.
 It has very limited memory.

8. Digital computer
A digital computer is an assembly of
electronic circuits that process data.
It has very high accuracy than an analog
computer.
It deals with discrete signals.
It is faster and can process alphanumeric
data.

9. Hybrid Computer
 A computer, which has the features of
both analog and digital computers, is
known as a hybrid computer.
 It can accept continuous changes of
physical quantities and converts them
digital information.
 They are very useful in space research.

10. Classification of computers according to their
efficiency
 Micro Computer
 Mini Computer
 Main Frame computer
 Super Computer.

11. Microcomputers
Microcomputers are the product of
latest development in
It makes use of the Large Scale
Integrated Circuit Technology (LSIC).

12.  A microcomputer is a small computer that is
built around microprocessors for processing.
 A processor that is built on an integrated
circuit (silicon chip) and which can function
as a Central Processing Unit (CPU) is known
as a microprocessor.
 It was first introduced in 1971 by Intel
Corporation and named as Intel 4004.

13. The various input, output devices and
memories are connected to the
microprocessor making it as a
microcomputer.
The speed of a microcomputer is in the
order of 100 Kilo instructions per
second (kips).

14. Microcomputers are of different types. They
are
 Personal Computers
 LAP TOP Computers
 Note Book Computers.

15. Mini Computers:
Only one person can use a PC at a
time but many persons can use Mini
computer.
The Mini computer has only one CPU
but has many terminals (VDUs) and
keyboards.

16.  If it has 20 terminals then 20 persons can use the
computer at a time.
 Mini computers are faster than microcomputers.
 Their memory capacity is around 32MB.
 They have Hard disks as Auxiliary memory
storage of capacity 10GB.

17. Main Frame Computers:
 Main Frame computers are machines with 32-
48-bit or 64-bit microprocessors with memory
capacity ranging from 32MB to 16GB.
 Several people can operate on it
 They have a speed of 10 million instructions per
second.
 Some examples are DEC-20, CDC-CYBER 170.

18. Super Computers:
Super computers are the most
sophisticated computers and cost in
crores of rupees.
They use 64-bit CPU chips and have a
speed of several billion operations per
second.

19.  Their memory capacities are several Giga bytes.
 They are used for weather forecasting,
crystallographic calculations, complex molecular
structural calculations and designing of supersonic
aircraft.
 CRAY, SUPERCRAY, CYBER 205 and SUPER SX I are
some super computers.