Question

A block of data is stored in memory locations starting from 3001 H. The length of the block is at 3000 H. Write an Assembly Language Program that searches for the first occurrence of data AO H in given block. Store the address of this occurrence in H-L pair. If the number is not fou nd then H-L pair should contain 0000 H.

Answer 1

Label	Opcode Operand	Comments
UP:	LDA 3000 H	; Copy block length into accumulator
	MOV C, A	; Copy block length from accumulator to Reg C
	LXI H, 3001 H	; Load H – L pair with starting address
	MVI A, AOH	; Initialise search element (AO) in register A
	CMP M	; Compare number in memory to the number AOH
		in accumulator
end:	JZ end	; Number in memory is AO? Yes, jump to end.
	INX H	; Increment H - L pair
	DCR C	; Decrement contents of block length counter Reg C
	JNZ UP	; Repeat all steps until all locations are checked
	LXI H, 0000 H	; Load H – L pair with address 0000 H
	RST 1	; Restart