We're in the process of studying the rehosting of an Access 97 application in Access 2000 or XP. Part of this application communicates with several serial devices through a S/W package called Crosstalk which is published by Attachmate. It uses DDE to communicate and is somewhat buggy. I'd like to write the comm pieces in VBA, eliminating the need for a replacement for Crosstalk, but have been unable to find anything out there that talks about how to do it. Since we're a DoD agency, using third party COM addins is possible, but would likely be painful to procure and certify, so I'd like to just do it from scratch. Can anyone point me to a source of info for how to implement serial comm capabilities in VBA?