From CDOT Wiki
Draws the text area and then starts the editing from the fist line.<br />
The whole text should scroll to left, write, up or down instead, if the cursor tries to pass the edges of the text area.<br />
When Enter key is hit, if in insertmode, a new line is inserted after the current line and any text after the cursor in
that line should be moved into it.<br />
When Backspace key is hit at the beginning of the line, the content of the current line should be moved to the previous line, the and current line should be deleted. The cursor in this case should stand in front of the copied data. <br />
:''Note that this will not happen if the sum of the length of the current and previous lines are more than FW_MAX_LINE_CHARS''