Question

A block of data is stored in memory location 4500 H. The length of block is stored in memory location 44FFH. Write Assembly Language Program that searches for the first occurrence of data D9H in given block. Store the address of this occurrence in H.L. pair. If the number is not found then HL. pair should contain 5000 H.

Answer 1

Label	Mnemonics	Comments
	LXI H, 44FFH	; Set H-L pointer to 44FFH
	MOV C, M	; Set count = [44FF]
	MVI A, D9H	; Set [Acc.] = D9 H
Loop :	INX H	; [H-L] = [H-L] + 1
	CMP M	; Is [M-L] = D9H ?
	JZ escape	; escape, if [M-L] = D9 H
	DCR C	; count = count - 1
	JNZ Loop	; repeat, if count  0
	LXI H, 5000 H	; Set H-L pair to 5000 if number is not found
escape :	RST 1.0	; Restart