DW CS4 has a new split code view. Use: View > Split Code from the main menu.
You might not have found it because a button was not added to the toolbar with the Code, Split, and Design buttons for the sake of avoiding confusion. The good news is that the markup to add the button was left in the Configuration/Toolbars/toolbars.xml file, but simply “commented out”. So, you can “uncomment” the markup if you’d like that button on your toolbar.
By Randy Edmunds
Comments (4)
Created
January 20, 2009

In split view – how to keep the source code view from moving when the lower scennd/frame is adjusted
HI. I am trying to enable it in CS5, but uncommenting the file is not showing the button… is it still possible to do with this version?
@Mario Be sure that you are editing the file in the correct Configuration folder. Edit the one in the User Configuration folder, which overrides the one in the Application Configuration folder. See this TechNote for more information:
http://help.adobe.com/en_US/dreamweaver/cs/extend/WS5b3ccc516d4fbf351e63e3d117f508c8de-7fdb.html
Thanks! This was quite helpful. I can confirm this works on OSX in CS5, just navigate to Configuration/Toolbars/toolbars.xml in the dreamweaver folder in applications, open the file in dreamweaver and uncomment the first comment you see. Restart your dreamweaver and the button will appear