PUBLIC _invert
.MODEL SMALL
.CODE

_invert PROC
	PUSH BP
	MOV BP,SP
	PUSH SI
	PUSH DI
	MOV AX,DS
	MOV ES,AX
	MOV DI,WORD PTR[BP+4]
	MOV SI,DI
	XOR AX,AX
	MOV CX,0FFFFH
	REPNE SCASB
	SUB DI,2
	NOT CX
	DEC CX
	SHR CX,1
CICLO:  MOV AH,[SI]
	XCHG AH,[DI]
	MOV [SI],AH
	INC SI
	DEC DI
	LOOP CICLO
	MOV AX,WORD PTR[BP+4]
	POP DI
	POP SI
	POP BP
	RET
_invert ENDP
END