import "io"

let slow() be
{ while true do
  { for i = 1 to 15 do
      assembly
      { pause }
    outch('.') } }

let set_timer(t) be
{ assembly
  { load  r1, [<t>]
    setsr r1, $timer } }

let timer_gone() be
{ out("\nBoo!\n");
  set_timer(1000000);
  ireturn; }

let key_pressed() be
{ let c;
  devctl(dc_terminc, 1, @c);
  out("You pressed the '%c' key\n", c);
  ireturn }

let start() be
{ let iv = vec(14);

  for i = 0 to 13 do
    iv ! i := nil;
  iv ! 7 := timer_gone;
  iv ! 9 := key_pressed;
  assembly
  { load r1, [<iv>]
    setsr r1, $intvec
    load r1, 0
    setfl r1, $ip }
  set_timer(1000000);

  slow() }