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16
STEP
14: Press the CRSR UP/DOWN key several times. You will observe that the text you
typed at the bottom of the screen will move up toward the top of the display.
The screen only scrolls from the bottom up. Prove this by pressing CLR/HOME
to move the cursor to the top of the screen.
Try
scrolling the screen down by
holding the SlfiFT key down and press the CRSR UP/DOWN key repeatedly.
Notice that this does not affect the screen.
THE. I'" THE BCtTTOI'l.
CURSOR CONTROL MODES
There are two modes of cursor control:
• direct, and
• programmed control
While under direct control, the cursor can be moved or editor function altered as soon as a
key
is
depressed. While under programmed control, cursor movement can be programmed to
occur during the execution of a program.
Programmed control is achieved by either of two means: insert mode or quote mode.
Typing an odd number of quotation marks before the cursor places the screen editor into
quote mode. While in quote mode, all cursor control keys with the exception of RETURN
and DELETE keys will print a reverse field character when keyed. Limited editing can still
be performed with the DELETE key. Exit from quote mode is accomplished by typing
another quote or pressing the RETURN key. The ESC key, if activated on your computer,
will also allow an exit back to direct cursor control from either quote or insert mode.
Entry to insert mode is gained by keying INST one or more times. No editing functions are
available for direct control while in insert mode and the number of characters that can be
inserted are limited to the number of times INST was keyed. Exit from insert mode is
accomplished by pressing either the RETURN or ESC key.
Twenty control keys and eleven control functions in screen editor provide a powerful
instruction set that allows the user to perform editing techniques such as:
• changing the limits of the scrolling window
• deleting entire lines
• ringing a carriage return bell at the end of a line
• using programmed cursor movement to create graphic figures on the screen
• modifying programs by simply typing over the listed line
and more.
NOTES
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