Commodore VIC-20 Programmer's Reference Manual page 46

4. Insert mode ^^
The spaces created by using the insert ■■■ key have some of
the same characteristics as quote mode. The cursor controls and
color controls show up as reversed characters. The only difference
is in the BB a=-d WjA BB, which performs its normal function
even in quote modeT now creates the T] . And ^m, which created
a special character in quote modeT inserts spaces normally.
Because of this, it is possible to create a PRINT statement
containing DELetes, which cannot be PRINTed in quote mode.
Here is an example of how this is done:
10 PRirsTTHELLO"
which displays as
10 PRINT'HELLO[T][t]P"
When the above line is RUN, the word displayed will be HELP,
because the last two letters are deleted and the P is put in their
place.
WARNING: The DELetes will work when LISTing as well as
PRINTing. so editing a line with these characters will be difficult.
The "insert mode" condition is ended when the RETURN (or
SHIFT RETURN) key is hit, or when as many characters have been
typed as spaces were inserted.
5. Other special characters
There are some other characters that can be PRINTed for
special functions, although they are not easily available from the
keyboard. In order to get these into quotes, you must leave empty
spaces forthem in the line, hit RETURN or SHIFT RETURN, and go
back to the spaces with the cursor controls. Now you must hit CTRL
RVS ON, to start typing reversed characters, and type the keys
shown below:
Function Type
SHIFT
switch
switch
disable
enable
RETURN
to tower case
to upper case
case-switching
case-switching
keys
keys
SHIFT
N
SHIFT
H
I
M
N
The SHIFT RETURN will work in the LISTing as well as
PRINTing, so editing will be almost impossible if this character is
used. The LISTing will also look very strange.
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