a4-1.asm

汇编语言的设计

STACK SEGMENT STACK
	DW 64 DUP(?)
STACK ENDS

CODE SEGMENT
	ASSUME CS:CODE

START:	MOV CX,0010H
	MOV SI,3100H
	MOV DI,3200H
 	CMP SI,DI
	JA A2
	ADD SI,CX
	ADD DI,CX
	DEC SI
	DEC DI
A1:	MOV AL,[SI]
	MOV [DI],AL
	DEC SI
	DEC DI
	DEC CX
	JNE A1
	JMP A3
A2:	MOV AL,[SI]
	MOV [DI],AL
	INC SI
	INC DI
	DEC CX
	JNE A2
A3:	JMP A3
CODE ENDS
     END START