Subject: Detecting F11 and F12

78. *****
 Q: How do I detect if the F11 or F12 key has been pressed?

 A: Here is a sample program
  uses Dos;
  (* Enhanced keyboard ReadKey, no Crt unit needed. Detects also F11
     and F12, and distinguishes between the numeric keypad and the
     gray keys. Lower part of the word returns the first scan code,
     the higher part the second *)
  function RDENKEFN : word;
  var regs     : registers;
      keyboard : byte absolute $40:$96;
  begin
    rdenkefn := 0;
    if ((keyboard shr 4) and 1) = 0 then exit;
    FillChar (regs, SizeOf(regs), 0);
    regs.ah := $10;
    Intr ($16, regs);
    rdenkefn := regs.ax;
  end;  (* rdenkefn *)
  {}
  procedure TEST;
  var key : word;
  begin
    while Lo(key) <> 27 do  { esc exits }
      begin
        key := RDENKEFN;
        if (Lo(key) = 0) and (Hi(key) = 133) then
          writeln ('F11 was pressed');
        if (Lo(key) = 0) and (Hi(key) = 134) then
          writeln ('F12 was pressed');
      end;
  end;
  {}
  begin TEST; end.
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