Computer architecture and organization focus on the internal workings and structural implementation of a computer system. Architecture refers to the external attributes visible to the programmer, while organization pertains to the practical implementation that realizes these architectural specifications. Understanding these concepts is essential for designing efficient computer systems, with architecture dealing with high-level design and organization with low-level design.

1. Concept of Computer Architecture and
Organization
Computer Organization and Architecture is the study of internal
working, structuring and implementation of a computer system.
• Architecture :- in computer system, same as anywhere else, refers to
the externally visual attributes of the system. Externally visual
attributes, here in computer science, mean the way a system is visible
to the logic of programs (not the human eyes!). In more general
language, Architecture of computer system can be considered as a
catalog of tools available for any operator using the system
• Organization:- of computer system is the way of practical
implementation which results in realization of architectural
specifications of a computer system. Simply Organization will be the
way the system is structured so that all those cataloged tools can be
used, and that in an efficient fashion.

3. Architecture Vs. Organization
Computer Architecture Computer Organization
It refers to those attributes of a system
visible to the programmer
It refers to the Implementation of these
features is mostly not known to the
user
Instruction set, Number of bits used for
data representation, Addressing
Modes etc. form the computer
architecture
Control signal, interface, memory
technology etc. form the part of
computer organization
e.g. there is multiple instruction e.g. there is dedicated hardware to
multiply
All Intel 80x86 microprocessors share
same basic architecture
All Intel 80x86 microprocessors differ
in their organization

4. Architecture Vs. Organization
Computer Architecture Computer Organization
Computer Architecture is concerned with the
way hardware components are connected
together to form a computer system.
Computer Organization is concerned with the
structure and behaviour of a computer system
as seen by the user.
It acts as the interface between hardware and
software.
It deals with the components of a connection in
a system.
Computer Architecture helps us to understand
the functionalities of a system.
Computer Organization tells us how exactly all
the units in the system are arranged and
interconnected.
A programmer can view architecture in terms of
instructions, addressing modes and registers.
Whereas Organization expresses the realization
of architecture.
While designing a computer system architecture
is considered first.
An organization is done on the basis of
architecture.
Computer Architecture deals with high-level
design issues.
Computer Organization deals with low-level
design issues.
Architecture involves Logic (Instruction sets,
Addressing modes, Data types, Cache
optimization)
Organization involves Physical Components
(Circuit design, Adders, Signals, Peripherals)

5. Fundamental Units of Computer

7. Input Devices:- This devices are used to enter the
data raw material needed for the processing to give output .

8. Input Devices

11. Output Devices:- This are the devices used to display or give output
which is processed by computer. The processing is on the data provided
by input devices by CPU or microprocessor.

12. Output Devices

13. Functional Units of Computer
Stucture and Function
Registers
CPU

14. Central Processing Unit (Microprocessor 8085)

19. Control Unit
• The control unit (CU) is a component of a computer's
central processing unit (CPU) that directs the operation of
the processor. It tells the computer's memory, arithmetic
and logic unit and input and output devices how to respond
to the instructions that have been sent to the processor.
• Control unit generates timing and control signals for the
operations of the computer. The control unit communicates
with ALU and main memory. It also controls the
transmission between processor, memory and the various
peripherals. It also instructs the ALU which operation has to
be performed on data.

21. Registers
• Registers:- are a type of computer memory
used to quickly accept, store, and transfer data.
• Types of Registers:-
– Accumulator (8bit)
– General Purpose registers (B,C,D,E,H,L) (8bit)
– Program Counter (PC)(16bit)
– Stack Pointer (SP) (16bit)
– Instruction Register/ Temporary Reg.

23. Computer Interconnection

24. LDA 2500H