DDE is _very_ slow. It is also considered obsolete. You want to use OLE Automation (COM) instead. You should be able to find hundreds of example programs for using COM to drive Excel from VC on the Web. There are also some good examples in Microsoft's MSDN site. Bob Ammerman RAm Systems ----- Original Message ----- From: "John Pearson" To: "pic microcontroller discussion list" Sent: Friday, April 29, 2005 1:58 AM Subject: [OT:] Is DDE that slow? I am trying to incorporate DDE into a MS VC++ MFC program. The program receives serial input, and I want to pass it along to Excel via DDE. As soon as I make the first data poke to Excel, my program slows down so much I can see each serial port character displayed on the screen one by one, instead of a line of data appearing instantly (9600 baud), even while there is no more data being sent to Excel. If I break the DDE connection, the program resumes normal speed again. Is this typical of DDE, or is something wrong somewhere. Or is there some kind of messaging continuing between Excel and my app even while there is no DDE data exchanges occuring? Please suggest I use COM only if you have some well documented stand-alone VC code examples I can incorporate into an MS VC++ MFC app. Thanks John -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist