CP/M/CPM_CDROM.iso/mbug/mbug130.arc/JOYSTICK.INC

Text File | 1979-12-31 | 896b | 31 lines

{ JOYSTICK.INC - routines for using joystick
  Written by Keith Wood             15/04/89 }

var    joy_avail : boolean;    { joystick present ? }

procedure init_joystick;       { initialise PIO }
begin
  port[1] := 255;
  port[1] := 255
end;

function joystick : byte;      { read joystick setting,
                                 bit 0 - up, bit 1 - down,
                                 bit 3 - left, bit 4 - right,
                                 bit 7 - fire }
var    j: byte;
begin
  j := 0;
  if joy_avail then j := not port[0] and $8F;
  if j>0 then delay(100);
  joystick := j
end;

procedure check_joy;           { check joystick present,
                                 sets joy_avail accordingly }
begin
  init_joystick;
  joy_avail := true;
  joy_avail := joystick<>$8F;
end;