'This is a small change to the fantastic Space Invaders Game by Les.
		'I have just built my own Proton Development Board and used this program to test it.
		
		'The change is simply to add a high score to the game.
		'It only stores the score and as yet no name can be stored.
		
		'I am using the on board eeprom for storage, the first 4 bytes are to hold the Dword value
		'of the high score and the fifth byte is used to check if the program has been run
		'before by testing the value is 255, if it is the high score is set to zero.
		'The next time the chip is switched on the value in the fifth byte is zero so the high score
		'is not set to zero as it should hold the latest high score value generated at the game over
		'routine. 

		'----------------------------------------------------------------------------------------
		'add these two lines after the "PORTB_PULLUPS = ON" approx. at line 233 moving the "Cls"
		'down two lines
		
		a=eread 4'check eeprom to see if this is the first time the program has been run
		if a=255 then ewrite 4,[0]:high_score=0:ewrite 0,[high_score]'if so;set eeprom to ignore next time and make high_score=0
		
		'----------------------------------------------------------------------------------------
		
		
		'----------------------------------------------------------------------------------------
		'add this line after the "Print at 4,1,"PRESS FIRE TO START"" approx. line no 1175 moving
		'"While FIRE_BUTTON = 1 : Wend" down one line
		
		gosub check_high_score
		
		
		'----------------------------------------------------------------------------------------
		
		
		'----------------------------------------------------------------------------------------
		'add this routine at approx line 1182 between the "Goto MAIN_PROGRAM_LOOP" and the Font table
		
check_high_score:
				 high_score=eread 0'check last stored high score
				 
				 if score<=high_score then return'if present score is less than high score return to "game over"
				 
				 ewrite 0,[score]'store new high score in eeprom
				 print at 5,0,"      WELL DONE      "'if we have a new high score then print message!
				 print at 6,0,inverse 1,"** NEW HIGH SCORE ** "
				 print at 7,0,inverse 0,"---- ",dec score," Points -------"
				 
				 return
				 
		'----------------------------------------------------------------------------------------
		
		'----------------------------------------------------------------------------------------
		'this line prints the High Score in the "Scoring" screen
		'add it after "Print at 0,7,"Scoring"" line in the "MAIN_PROGRAM_LOOP" routine at approx.
		'line 962
		
		print at 1,0,"HIGH SCORE= ",dec eread 0
		
		'----------------------------------------------------------------------------------------
		
		
		'Also at approx. line 1172 there is a "Cls" command which is commented out('Cls) I have
		'uncommented this as it makes the end screen work better when the high score is used.
		
		'I hope some of you try it as it makes the game more addictive to me!
		
		'must go, got to beat that HIGH SCORE.
		
		'73 de Mark G0EBB