8085 program to search a number in an array of n numbers

In this program we will see how to search an element in an array of bytes using 8085.

Problem Statement

Write 8085 Assembly language program to search a key value in an array of data using linear search technique.

Discussion

In this program the data are stored at location 8002H to 8007H. The 8000H is containing the size of the block, and 8001H is holding the key value to search. After executing this program, it will return the address of the data where the item is found and store the address at location 9000H and9001H. If the item is not found, it will return FFFFH.

If the data is present in the memory at FFFFH, then also it will store FFFFH, so it is ambiguous condition. We are assuming that the data are not stored atFFFFH, so we have chosen that value to indicate the data is not present.

Input

Address	Data
...	...
8000	06
8001	55
8002	11
8003	22
8004	33
8005	44
8006	55
8007	66
...	...

Flow Diagram

Program

Address	HEX Codes	Labels	Mnemonics	Comments
F000	21, 00, 80		LXI H,8000H	Point to get array size
F003	4E		MOV C, M	Get the size of array
F004	23		INX H	Point to next location
F005	46		MOV B, M	Get the key value to search
F006	78		MOV A, B	Take the key into acc
F007	23	LOOP	INX H	Point to next location
F008	BE		CMP M	Compare memory element with Acc
F009	CA, 19, F0		JZ FOUND	When Z flag is set, go to FOUND
F00C	0D		DCR C	Decrease C by1
F00D	C2, 07, F0		JNZ LOOP	When Count is not 0, jump to LOOP
F010	21, FF, FF		LXI H, FFFF	Load FFFFHinto HL pair
F013	22, 00, 90		SHLD 9000H	Store at9000H
F016	C3, 1C, F0		JMP DONE	Jump to DONE
F019	22, 00, 90	FOUND	SHLD 9000H	Store at9000H
F01C	76	DONE	HLT	Terminate the program