program extest (input, keyboard, output) ;
  var
    s : string ;
    ch : char ;
    
  begin
    ! andcc #$ef ;
    writeln ;
    writeln ('Enter lines, they will be repeated until you type "stop"') ;
    repeat
      readln (s) ;
      writeln (s)
    until s = 'stop' ;
    writeln ('Enter characters, their hex value will be shown') ;
    writeln ('Terminates when you type a "@"') ;
    repeat
      read (keyboard, ch) ;
      writeln (hex(ch))
    until ch = '@' ;
    writeln ('I will now turn off interrupts and go into an infinate loop') ;
    ! orcc #$10 ;
    repeat until false
  end.
