The serial port object (System.IO.Ports.SerialPort) is multithreaded. Just
use as many instances as you need, and each will read, effectively,
simultaneously.
Dick
--
Richard Grier, MVP
Hard & Software
Author of Visual Basic Programmer's Guide to Serial Communications, Fourth
Edition,
ISBN 1-890422-28-2 (391 pages, includes CD-ROM). July 2004, Revised March
2006.
See www.hardandsoftware.net for details and contact information.