Question

A block of fifteen memory locations begins D200 H. Write an assembly language program to convert each data in the block into its 1's complement. Store the result at locations beginning D300 H.

Answer 1

Label	Mnemonics code	Comments
	LXI D, D300 H	; Load D300H in DE pair
	LXI H D200 H	; Load D200H in HL pair
	MVI B, 0F H	; Move of in B immd
Back:	MOV A, M	; Copy M into A
	CMA	; Complement ACI's
	STAX D	; Store A into memory via DE
	INX H	; Increment HL pair by 1
	INX D	; Increment DE pair by 1
	DCR B	; decrement B by 1
	JNZ Back	; Jump on no zero
	HLT	; Halt the process