Description: 80-Column Text Card: Applesoft Control Codes (11/96)
Header: 80-Column Text Card: Applesoft Control Codes (11/96)

 Article Created: 1 January 1986
 Article Reviewed/Updated: 14 November 1996

 TOPIC -----------------------------------------------------------

 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.

 DISCUSSION ------------------------------------------------------

 Table of Control Character Codes:

 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

                  Apple      ASCII
 Control    ASCII  IIe        Decimal        What
 Character  Name   Name       Code    Notes  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     NAK    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.

 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


 Article Change History:
 14 Nov 1996 - Reviewed for technical accuracy, revised formatting.
 Copyright 1986-96, Apple Computer, Inc.
 Keywords: