Microprocessor 8085 program to find Largest number

In the third year of the B.Sc. Physics practical program under TANSCHE, it's crucial to grasp how microprocessors work. A significant part of this involves the Microprocessor 8085, which is a popular 8-bit processor. In this experiment, students get to practice basic arithmetic operations.

This blog post will highlight the experiment on finding the the larger number between two numbers / largest number in a data array using the Microprocessor 8085. This hands-on activity helps students dive into the essential features of the 8085 microprocessor, including programming logic and memory functions. By completing this task, you'll develop a clear understanding of how the 8085 processes data and performs arithmetic operations, laying a strong groundwork in microprocessor systems.

Microprocessor 8085 program to find Largest number

Aim:

Write an assembly language program to find the larger number between two numbers / largest number in a data array using microprocessor 8085.

Apparatus required:

Microprocessor 8085 kit, power supply etc

Program:

Larger number between two numbers

Memory address	Machine code	Mnemonics	Operands	Comments
8000	21	LXI	8501H	Address of the first number in memory location
8001	01
8002	85
8003	7E	MOV	A, M	Move the number to the accumulator
8004	23	INX	H	Address of the second number in memory location
8005	BE	CMP	M	Compare the numbers
8006	D2	JNC	800AH	Is it the smallest number in the accumulator? Go to 800A
8007	0A
8008	80
8009	7E	MOV	A, M	Move the number to the accumulator
800A	32	STA	8503H	Store the number in accumulator to 8503H
800B	03
800C	85
800D	76	HLT		Stop the program

Example:

2’s complement of 8-bit number

First input location 8501H - 15H

Second input location 8502H - 25H

Result location 8503H - 25H

Youtube demo:

Largest number in a data array

Memory address	Machine code	Mnemonics	Operands	Comments
8000	21	LXI	8501H	Address of the LSB of the number
8001	01
8002	85
8003	4E	MOV	C, M	Count register
8004	23	INX	H	Address of the first number in memory location
8005	7E	MOV	A, M	Move the number to the accumulator
8006	0D	DCR	C	Decrement the count register
8007	23	INX	H	Address of the next number in memory location
8008	BE	CMP	M	Compare this number with the previous number
8009	D2	JNC	800DH	Is it the smallest number in the accumulator? Go to 800D
800A	0D
800B	80
800C	7E	MOV	A, M	Move the number to the accumulator
800D	0D	DCR	C	Decrement the count register
800E	C2	JNZ	8007H	Is C non-zero? Go to 8007H
800F	07
8010	80
8011	32	STA	8450H	Store the result in 8450H
8012	50
8013	84
8014	76	HLT		Stop the program

Example:

2’s complement of 16-bit number

        Number of data in a array 8500H - 06

First input location 8501H - 15H

Second input location 8502H - 24H

Third input location 8503H - 36H

Fourth input location 8504H - 17H

Fifth input location 8505H - 10H

Sixth input location 8506H - 02H

Result location 8450H - 36H

Youtube demo:

Result: 

The assembly programmes for microprocessor 8085 for finding the larger number between two numbers / largest number in a data array were written and executed using the microprocessor 8085 kit.

Click here for Smallest number

For further reading:
External site