Topic       : The GFA-Basic Compendium
Author      : GFA Systemtechnik GmbH
Version     : GFABasic.HYP v2.98 (12/31/2023)
Subject     : Documentation/Programming
Nodes       : 899
Index Size  : 28056
HCP-Version : 3
Compiled on : Atari
@charset    : atarist
@lang       : 
@default    : Document not found
@help       : Help
@options    : +g -i -s +z
@width      : 75
@hostname   : STRNGSRV
@hostname   : CAB     
@hostname   : HIGHWIRE
@hostname   : THING   
View Ref-FileKEYTEST n
KEYGET n
KEYLOOK n

n: ivar

KEYTEST is similar to INKEY$ and reads a character from the keyboard. If no key
was pressed since the last input (apart from Alternate, Control, Shift, and
Caps Lock) the returned value is zero, otherwise its value corresponds to the
key in the table shown below for KEYGET.

KEYGET waits for a key to be pressed and then returns a long word value
corresponding to the key. This 32-bit long word is constructed as follows:

    Bits  0- 7: ASCII code
    Bits  8-15: Zero
    Bits 16-23: Scan code
    Bits 24-31: Status of Shift, Control, Alternate, and CapsLock as follows:

    Bit  Key
    0    Right shift
    1    Left shift
    2    Control
    3    Alternate
    4    Caps lock

KEYLOOK allows a character to be read from the keyboard buffer, without
changing the buffers contents, as with KEYGET or INKEY$.

If n is a byte or word variable then an integer conversion takes place
automatically.

Examples:

    PRINT "Please press ESCape"
    REPEAT                            !The program runs through the loop
    UNTIL INKEY$=CHR$(27)             !until the ESCape key is pressed.
    '
    PRINT "Please press ESCaPe again"
    REPEAT                            !Again runs through the loop but
      KEYTEST n|                      !this time checks the keyboard here for
    UNTIL n|=27                       !character number 27.

--> Waits twice for the ESCape key to be pressed. Note that in the second
    example bits 0 to 7 are masked off automatically by using a byte-sized
    (8-bit) variable.

    PRINT "Please press a key"
    key_1|=INP(2)                    !Waits for a key-press.
    PRINT "Press another key please"
    KEYGET key_2|                    !Waits again.
    PRINT "INP(2): ";key_1|          !The ASCII codes of the depressed
    PRINT "KEYGET: ";key_2|          !keys are printed.

--> Waits twice for keys to be pressed, and displays their ASCII codes.

    REPEAT
      KEYLOOK n%
    UNTIL n%
    INPUT "Type in something ";a$

--> Waits in a loop until a key is pressed, then begins the input of a$ without
    losing the initial character.

    DO
      KEYGET a%
      PRINT HEX$(a%,8),BIN$(a%,32),
      OUT 5,a%
      PRINT
    LOOP

--> Waits for a key to be pressed and displays the value returned by KEYGET in
    both hexadecimal and binary.

Note: OUT 5,a% allows the characters associated with control codes 0-32 to
      be displayed.

Cnecin()+ Iorec()+