Puertos

USB
http://www.icsharpcode.net/OpenSource/SharpUSBLib/default.aspx


Open and read COM port data using System.IO.Ports in C# and VB .NET 2.0
http://www.devasp.net/net/articles/display/727.html

Threading
http://bytes.com/topic/c-sharp/answers/248913-threading-system-io-ports

Serial communications
http://www.codeproject.com/KB/cs/serialcommunication.aspx

http://social.msdn.microsoft.com/forums/es-ES/vcses/thread/b95676f5-e07f-478b-b3b1-f0abb0d9e94b/

Puerto Paralelo
http://es.wikipedia.org/wiki/IEEE_1284

http://msmvps.com/blogs/peplluis/archive/2009/01/22/acceso-al-puerto-paralelo-lpt-algo-m-225-s-que-encender-un-led-o-imprimir-un-doc.aspx

http://msmvps.com/blogs/peplluis/archive/2008/09/19/leer-los-ceros-y-unos-de-un-micro-controlador.aspx

http://msmvps.com/blogs/peplluis/archive/2009/01/22/acceso-al-puerto-paralelo-lpt-algo-m-225-s-que-encender-un-led-o-imprimir-un-doc.aspx

Puerto Mapa
http://www.doc.ic.ac.uk/~ih/doc/par/

dll
http://logix4u.net/Legacy_Ports/Parallel_Port/Inpout32.dll_for_Windows_98/2000/NT/XP.html