The main window contains:
- command button to exit the application
- fields to display information about the inbound line-21 data.
The Raw Input field contains inbound raw data, comprised of readable text and other control bytes that have been translated into readable data, representing the control bytes as colored alphabetic characters.
The Chars Rec'd field simply counts inbound data, again giving feedback that data is flowing into the system. You may notice the Chars Rec'd field incrementing when no new data is accumulating in the History fields. This is normal for line-21: there may be null characters received, and these are not visually represented in MoPix-21 to save space in the History fields. When null bytes are received, a message displays in the status bar at the bottom of the window.
These fields will periodically purge themselves so as not to accumulate too much data, and not to waste memory. They're really just there as a confirmation that data is flowing.