Reserve Stars COUNT : 
	Reserves memory for COUNT "STAR" definitions.
	It also computes in advance the address of the start of every line.
	This is done for more speed when displaying the 'STARS'.
	You can calculate the amount of memory needed with this formula:
	COUNT*8+Heigth of screen*2
	At this point you can reserve memory for 4000 'STARS'...
	So with 4000 'STARS' in a 320 by 250 screen, 32500 bytes are
	reserved.

Define Star NR,X,Y,X SPEED,Y SPEED :
	Defines 'STAR' NR.  X and Y are the initial coordinates of the 'STAR'.
	X SPEED and Y SPEED define the speed of the 'STAR'.
	So your 'STARS' can fly in any direction !

Display Stars :
	Displays the 'STARS' onto the screen and computes the next position
	of the 'STARS' depending on the X- and Y SPEEDS.
	I use only 1 bitplane (the first one), so only  1 coloured 'STARS'
	are possible... But you can change the colour of them with the
	Palette or Colour instructions ! This also counts for the F Stars
	command.
	I use the main processor (the MC68000) for displaying the 'STARS'.
	So people who have an A3000 or accelerator boards can display
	many more...
	Limits on a 68000 system (7.14 Mhz) only 'STARS' displayed :
		If you use only a X SPEED (Y SPEED = 0), then 670 'STARS'
		can be displayed in 1 VBL.
		If you use only a Y SPEED (X SPEED = 0), then 660 'STARS'
		can be displayed in 1 VBL.
		But if you use both speeds (X- and Y SPEED <> 0), then 540
		'STARS' can be displayed in 1 VBL. 
!!!	Allways be sure that you are displaying the 'STARS' on the screen
	where you reserved them. This is because I store the start-
	offsets of every line from the current screen when reserved.
	This technique gives more speed when the 'STARS' are displayed !!!

Stars Speed START To END,X SPEED,Y SPEED :
	Changes the speed of 'STARS' START To 'STAR' END with the values
	X SPEED and Y SPEED.

F Stars :
	Displays the 'STARS' onto the screen without computing the next
	'STAR' position. So your 'STARS' can be freezed without changing
	the SPEED of them !
!!!	Allways be sure that you are displaying the 'STARS' on the screen
	where you reserved them. This is because I store the start-
	offsets of every line from the current screen when reserved.
	This technique gives more speed when the 'STARS' are displayed !!!

Stars Compute START To END :
	Computes the next position of the 'STARS' START To END without
	displaying them on the screen.

Stars Erase :
	Gives back to the system the memory used by the Reserve Stars
	command.
	The Stars are now automatically erased from memory if you
	do a default or if you are leaving AMOS !

Stars Clip X,Y,X1,Y1 :
	The Stars Clip instruction limits all 'STARS' to a rectangular
	region of the screen.
	X,Y represent the coordinates of the top left corner of the
	rectangle, and X1,Y1 hold the coordinates of the bottom right
	corner.
	This instruction works fine now as it is, but is not really
	finished yet...somethimes you don't get what you want !

Stars Int On CLEAR :
	This command adds a new interrupt server to the VBLANK server
	chain which will do the same thing as the Display Stars command !
	So the Display Stars command is now executed every Vbl and is
	running totally independent of your AMOS PROGRAM !
	If CLEAR <> 0 the display will be cleared before displaying the
	'STARS'. This is the 'AUTOMATIC CLEAR MODE'.
	Only the 'STARFIELD PLANE' is cleared, this is the first bitplane.
!!!	Allways be sure that the SCREEN where you have reserved the 'STARS'
	remains open when the 'STARS INTERRUPT' is on. Otherwise a crash
	will be certain...I store the SCREEN ADRESS of the screen where
	the Reserve Stars command was executed. So the 'STARS' will 
	only be displayed in that particular screen.			!!!	

	Advantages : 
		     Time is saved for your AMOS PROGRAMS.
		     You don't have to wait for the Vbl to synchronize
		     the display of the stars with your screen display.

	Disadvantages :
		     Only the X-speed is changed (for more speed).
		     Can't be used with Double Buffered screens even
		     if Autoback is set to 0 (zero). I'll try to fix 
		     this in the future.
	
Stars Int Off :
	Turn off the 'STARS' interrupt.