It's not the case for serial comms. Excerpt from Win API help:

"The file input and output (I/O) functions (CreateFile, CloseHandle,=20
ReadFile, ReadFileEx, WriteFile, and WriteFileEx) provide the basic=20
interface for opening and closing a communications resource handle and
for performing read and write operations. The Microsoft=AE Win32=AE=20
application programming interface (API) also includes a set of=20
communications functions that provide access to communications
resources."
Including NT family.

It's true for directly read or write a hardware port (for example
reading
or writing directly from/to LPT, in assembler).=20

Cosmin Buhu
Easy Control/Rack Designer
http://www.easyvitools.com
Now talks serial and TCP/IP


Mitch Miller wrote:
> Gary,
>=20
> Programs which used to do direct hardware manipulation which would work=
 in
> Windows 95, 98 and ME probably will not work in XP.  The reason is that=
 XP
> is a derivative of the Windows NT / 2000 product lines which abstract
> hardware from the O/S, and do not permit direct HW manipulation from us=
er
> space.  In order to do HW manipulation under the NT/2k/XP products, you
> have to write a kernel device driver and install it.
...........................
>=20
> -- Mitch

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