The output of ECHO commands is not shown if the terminal window needs to scroll to show it. The entire line disappears.

To reproduce:

• open a cmd.exe window
• set the screen buffer size larger than window size (so the window can scroll).
• Type "echo A". You should see output similar to this:

  C:\Users\SkyLined>echo A
  A
  
  C:\Users\SkyLined>
  

• Repeat that command until you reach the bottom of the window and the window starts scrolling. You should no longer see the output of echo:

  C:\Users\SkyLined>echo A
  A
  
  C:\Users\SkyLined>echo A
  
  C:\Users\SkyLined>
  

Scrolling the window does not change this; the output has disappeared permanently.