8085 program to find 1's and 2's complement of 8-bit number

In this program we will see how to find 1's complement and 2's complement of an 8-bit number.

Problem Statement

Write 8085 Assembly language program to find 1's complement and 2's complement of a number stored in 8000H.

Discussion

8085 has an instruction CMA. This instruction complements the content of Accumulator. For 1's complement CMA instruction is sufficient, and for 2's complement we have to increase the number by 1 after complementing.

We are taking the number from 8000H and storing the 1's complement at location 8050H, and 2's complement to 8051H.

Input

Address	Data
. . .	. . .
8000	AB
. . .	. . .

Flow Diagram

Program

Address	HEX Codes	Mnemonics	Comments
F000	3A, 00, 80	LDA 8000H	Load the number from memory
F003	2F	CMA	Complement the accumulator
F004	32, 50, 80	STA 8050H	Store the 1's complemented result
F007	3C	INR A	Increase A by 1
F008	32, 51, 80	STA 8051H	Store the 2's complemented result
F00B	76	HLT	Terminate the program