I am trying to extend a Delphi 4 component for serial port handling to
use higher port numbers than 9 but I fail at this. :-(

The function that is used inside the component is the API call
CreateFile and the parameter passed as lpFileName for com ports 1-9 is
COM1, COM2 etc. When I try to extend this above 9 for example setting
the name to COM12 then CreateFile returns with an error code (cannot
find file specified) and the port is not opened.

Since I am no Win32 programming expert I need some pointer to what I
am doing wrong here. Or maybe CreateFile cannot be used for the higher
numbered com ports? (I do have comports 9-12 available for example
from Hyper terminal).

TIA

Bo Berglund
Software developer in Sweden
bo.bergl...@telia.com

PGP: My public key is available at the following locations:
Idap://certserver.pgp.com
http://pgpkeys.mit.edu:11371

Use a name like \\.\COM10.  The \\.\ part is optional for ports 1-9,
required for ports 10 and up.

--
"The privileged being which we call human is distinguished from other
animals only by certain double-edged manifestations which in charity we
can only call 'inhuman.'" -- Epiktistes

Im Artikel <392ee914.1739670...@nntpserver.swip.net>, bo.bergl...@telia.com (Bo
Berglund) schreibt:

Look into the system properties to find out the names of the excess ports?

DoDi

On 28 May 2000 01:13:49 GMT, vb...@aol.com (VBDis) wrote:

Not really,
as was pointed out by David Rifkind the proper com port names should
be \\.\COM<number>, only for ports 1-9 is one allowed to use the
shorter syntax. Probably because of backwards compatibility issues.
The correct naming system works for ALL ports so I have changed the
string generation in the component accordingly and it now works as it
should.
Thanks David!

Bo Berglund
Software developer in Sweden
bo.bergl...@telia.com

PGP: My public key is available at the following locations:
Idap://certserver.pgp.com
http://pgpkeys.mit.edu:11371