IBM 3270 User Manual page 42

Let's set some tab stops and the audible
"end of line" signal and see how they work.
I If you don't have an audible-alarm on your display,
I ignore the part of this tutorial that discusses the
"end of line" signal.
Press CHG FMT again to get back into change format mode.
(The scale line appears.)
Press the CLEAR key. (This clears all existing tab stops.)
Refer to the line below with three Xs on it. Move the cursor
along the scale line until it lines up with the first X.
I Press the Tab key. The tab key is the key with the arrow that
I points to the right located above the shift lock key.
The underscore symbol (J appears on the scale line. This indicates
that a tab stop is set at this position on the line.
X X X
Set tab stops at the other two X positions.
If you accidentally set a tab stop at an incorrect position,
place the cursor under it and press the Delete Character key
to clear the tab stop.
We will use these tab stops in a minute.
Move the cursor along the scale line until it lines up about
five positions to the left of the right margin and type the
* symbol. This sets the "end of line" signal at that
position on the line.
We will use the signal in a minute.
To clear the "end of line" signal, place the cursor
r I under it and press the Delete Character key. Type the
I * symbol again to set the "end of line" signal.
Press the CHG FMT key to turn off change format mode.
The scale line disappears.
Now you have margins, tab stops, and an "end of line"
signal set. Let's try them.
Use the spacebar to move the cursor along the following
blank line. The "end of line" signal sounds as the cursor
passes through the signal position on the line.
Return the cursor to the left margin and press the Tab key.
The cursor moves to the next tab stop.
Press the Tab key a few times and see how the cursor moves
from tab stop to tab stop.
Chapter 5. Entry Assist Tutorial 5-5