because Java is in a sandbox, direct routines that would allow such spiffy hacks as "multiple simultaneous keypresses" would have to be written, possibly with low-level assembler routines, which just aren't available in standard Processing.

A better way to do this is to use an array [] of keys and toggle them realtime as they are pressed with a multi-threaded solution.  then in the software, reference the keys.  that's the sort of 'hot keyboard' effect achieved by most videogames released since Mode-X in 1990.

You need to keep track of the key presses and releases yourself if you want ot chek on multiple keys.

This is a simple example for the two specific keys. You can extend on this to have any number you want...

Code:

boolean[] keys;

void setup()
{
  size(200, 200);
  framerate(5);
  keys=new boolean[2];
  keys[0]=false;
  keys[1]=false;
}
void draw() 
{
  if( keys[0]) 
  {  
    print("1");
  }
  if( keys[1]) 
  {
    print("2");
  }
}

void keyPressed()
{
  if(key=='a')
    keys[0]=true;
  if(key=='s')
    keys[1]=true;
}

void keyReleased()
{
  if(key=='a')
    keys[0]=false;
  if(key=='s')
    keys[1]=false;
}