Как узнать адрес LPT-порта?

Code:

function GetPortAddress(PortNo: integer): word; assembler; stdcall;

asm

push es

push ebx

mov ebx, PortNo

shl ebx,1

mov ax,40h // Dos segment adress

mov es,ax

mov ax,ES:[ebx+6] // get port adress in 16Bit way :)

pop ebx

pop es

end;