Commodore Plus 4 - Page 171

Screen Editing 159
same column) when you cursor past the bottom line. Text on the screen does not
move.
To turn normal scrolling back on, issue the ESCape L sequence.
You can make the screen display scroll up or down one line at a time with the
ESCape V and W sequences. ESCape V moves the screen display up one line;
ESCape W moves it down one line. The cursor can be located anywhere on the
screen; it does not have to be at the top or the bottom line. ESCape W always
displays a blank line at the top of the screen as text lines are moved down a line at
a time. ESCape V always displays a blank line at the bottom of the screen as text
lines are moved up a line at a time.
Both ESCape W and ESCape V functions work when scrolling is turned off by
ESCape M. In fact, ESCape V is the only way to scroll the top line off the screen
when normal scrolling is turned off.
Screen Editing
Previous sections in this chapter on screen editing have demonstrated some of the
techniques you can use to correct errors, save typing time, clear the screen (or just
delete some lines from it), and change the screen colors. Besides the features
described in these sections, you can also use the Escape functions to edit the
screen.
1. Inserting and deleting characters and lines on the screen.
2. Changing the screen size.
Insertion/ deletion and changing screen size are especially useful when you are
working on programs.
Automatic Insert Mode
The INSERT key lets you add as many characters as the number of times you
press the INSERT key. We might call this method of character insertion a manual
insert mode. Automatic insert mode, when engaged, lets you insert as many
characters as you like. Automatic insert mode saves time when you want to insert
more than one or two characters.
To turn on automatic insert mode, press the ESCape key and then the A key.
From then until you cancel the mode, all the characters you type are in insert
mode; regular insert mode rules are in effect. The cursor can be located anywhere
on the screen when you turn on automatic insert mode.
When you issue a RUN command while you are still in automatic insert mode
and there is information on the screen beneath the line where you issued RUN,