full list of TIL and KB articles

80-Column Text Card: Applesoft Control Codes

When you write BASIC programs while the 80-Column Text Card is active, there are a number of functions you can use by pressing the CTRL key in conjunction with another key. Functions activated by pressing these two-key combinations are called control character functions. Some control character functions work when you type them in from the keyboard as well as when used within PRINT statements in BASIC programs.
Table of Control Character Codes:
Control Character
ASCII Name
Apple IIe Name
ASCII Decimal Code
Notes
What is Executed
CTRL-G
BEL
bell
7
-
 Produces a 1000 Hz tone for 0.1 second
CTRL-H
BS
backspace
8
-
 Moves cursor position one space to the left; from left edge of window, moves to right end of line above.
CTRL-J
LF
line feed
10
-
 Moves cursor position down to next line in window; scrolls if needed.
CTRL-K
VT
clear EOS
11
1
 Clears from cursor position to the end of the window.
CTRL-L
FF
clear
12
1
 Moves cursor position to upper-left corner of window and clears window.
CTRL-M
CR
return
13
-
 Moves cursor position to left end of next line in window; scrolls if needed.
CTRL-N
SO
normal
14
1,3
 Sets display format normal.
CTRL-O
SI
inverse
15
1,3
 Sets display format inverse.
CTRL-Q
DC1
40-column
17
1,3
 Sets display to 40 columns.
CTRL-R
DC2
80-column
18
1,3
 Sets display to 80 columns.
CTRL-S
DC3
stop list
19
1,2
 Stops sending characters to the display until a key is pressed.
CTRL-U
CTRL-U
quit
21
1,3
 Deactivates 80-column Text Card, homes cursor, and clears screen.
CTRL-V
SYN
scroll
22
1
 Scrolls the display down one line, leaving the cursor in the current position.
CTRL-W
ETB
scroll up
23
1
 Scrolls the display up one line, leaving the cursor in the current position.
CTRL-Y
EM
home
25
1
 Moves cursor position to upper-left corner of window (but doesn't clear).
CTRL-Z
SUB
clear line
26
1
 Clears the line the cursor position is on.
CTRL-\\
FS
forward
28
1
 Moves cursor position one space to the right; from right edge window, moves it to left end of line below.
CTRL-]
GS
clear EOL
29
1
 Clear line from cursor position to the right edge of the window.
CTRL-^
RS
gotoXY
30
1,4
 Using the next two characters, minus 32, as one-byte X and Y values, moves the cursor postion to CH=X, CV=Y.
Key to Notes codes:

1 - Only available when 80-Column Text Card is active
2 - Only works from the keyboard, not in a program
3 - Only works in a program, doesn't work from the keyboard
4 - Not supported under BASIC

The Apple 80-Column Card in an Enhanced IIe has some additional features documented in the Programmer's Guide to the Enhanced IIe.


Important Information About CTRL-U
==================================

A "CHR$(21)" response (Control-U) to a "GET A$" input statement in a BASIC program may disable the 80-column card on an Apple IIGS, Apple IIe, Apple IIc, and Laser 128 (but not an Apple II Plus with Applied Engineering's Viewmaster 80).

To halt the CONTROL-U function, the CONTROL-U keystroke needs to be trapped on input. Using the "GET A$" method:

10 GET A$
20 IF A$ = CHR$(21) THEN A$ = "" :REM traps the CONTROL-U, sets it to blank
30 PRINT A$;
40 GOTO 10
Published Date: Feb 19, 2012