I had no problem making the changes, I just didn't know if there were any limits in the DLL for maxbaud. I have tested the dll to 1M. I have a USB/serial uart that can talk to a micro at up to 2mbs. The project uses non-standard baud rates with a common divisor. I will test @ 2M later in the project (I really don't need but 1M for the current project I am working on) (Monitoring a HS-CAN network in a car) Here is the changelog and I have attached the modified version of the sample app. The example/sample was a great starting point! I do need to look at the strip lf checkbox, from a quick scan I think the UI is there, but the code is commented out. (I moved on) ;Version 2.1 21th June 2011 ;changes- ;Added $progname variable and utilized in all titles. ;bugfix - version of dll shown as unknown until port setting menu closed. ;changed output window to courier font. Monospaced fonts easier to read if data is lined up in terminal output. ;changed - removed sorting of baud rate in drop down window. Sorting was from left character, not from numeric value. ;changed/added additional "standard baud rates": 300, 230400, 460800, 921600 as well as 1000000 and 2000000 (Tested to 921600) ;bugfix - only display error message box if error exists. ;bugfix - fixed spelling of "quit" from "quite" Thank you again for your work and attention! Mark Cheavens CommgExampleA.au3