diff --git a/interlace_demo/Makefile b/interlace_demo/Makefile
index e67a2262..b8547425 100644
--- a/interlace_demo/Makefile
+++ b/interlace_demo/Makefile
@@ -43,7 +43,7 @@ SPRITES:	sprites.o
 	ld65 -o SPRITES sprites.o -C ../linker_scripts/apple2_1000.inc
 
 sprites.o:	sprites.s gr_copy.s \
-	sprites_screen.s sprites_table.s movement_table.s earth.inc
+	sprites_screen.s sprites_table.s movement_table.s earth.inc asteroid.inc
 	ca65 -o sprites.o sprites.s -l sprites.lst
 
 
diff --git a/interlace_demo/asteroid.inc b/interlace_demo/asteroid.inc
new file mode 100644
index 00000000..52172478
--- /dev/null
+++ b/interlace_demo/asteroid.inc
@@ -0,0 +1,21 @@
+; all hard-coded 3x2
+
+asteroid_p1:
+.byte	$50,$85,$80
+.byte	$05,$88,$08
+
+explode0_p1:
+.byte	$50,$85,$80
+.byte	$05,$88,$08
+
+explode1_p1:
+.byte	$50,$85,$80
+.byte	$05,$88,$08
+
+explode2_p1:
+.byte	$50,$85,$80
+.byte	$05,$88,$08
+
+void_p1:
+.byte	$00,$00,$00
+.byte	$00,$00,$00
diff --git a/interlace_demo/gr_putsprite.s b/interlace_demo/gr_putsprite.s
index 10c09bc3..11d73ba9 100644
--- a/interlace_demo/gr_putsprite.s
+++ b/interlace_demo/gr_putsprite.s
@@ -2,37 +2,32 @@
 	; put_sprite
 	;=============================================
 	; Sprite to display in INH,INL
+	; Assumes sprite size is 3x2
 	; Location is SPRITE_XPOS,SPRITE_YPOS
 	; Note, only works if SPRITE_YPOS is multiple of two
 
 	; NO TRANSPARENCY
 
-	; 28+ Y*(34+17+X*(18+13) + 5
-	; 33 + Y*(51+31*X)
+	; 13+ Y*(33+17+X*(18+13) + 5
+	; 18 + Y*(50+31*X)
 
-	; so if 3*2 = 321 cycles??
+	; so if 3*2 = 304 cycles??
 
 put_sprite:
-
-	ldy	#0		; byte 0 is xsize			; 2
-	lda	(INL),Y							; 5
-	sta	CH		; xsize is in CH			; 3
-	iny								; 2
-
-	lda	(INL),Y		; byte 1 is ysize			; 5
+	ldy	#0							; 2
+	lda	#2		; ysize is 2				; 2
 	sta	CV		; ysize is in CV			; 3
-	iny								; 2
 
-	lda	SPRITE_YPOS		; make a copy of ypos			; 3
+	lda	SPRITE_YPOS	; make a copy of ypos			; 3
 	sta	TEMPY		; as we modify it			; 3
 								;===========
-								;	28
+								;	13
 put_sprite_loop:
 	sty	TEMP		; save sprite pointer			; 3
 	ldy	TEMPY							; 3
 	lda	gr_offsets,Y	; lookup low-res memory address		; 4
 	clc								; 2
-	adc	SPRITE_XPOS		; add in xpos				; 3
+	adc	SPRITE_XPOS		; add in xpos			; 3
 	sta	OUTL		; store out low byte of addy		; 3
 	lda	gr_offsets+1,Y	; look up high byte			; 4
 	adc	DRAW_PAGE	;					; 3
@@ -41,9 +36,9 @@ put_sprite_loop:
 
 				; OUTH:OUTL now points at right place
 
-	ldx	CH		; load xsize into x			; 3
+	ldx	#3		; load xsize into x			; 2
 								;===========
-								;	34
+								;	33
 put_sprite_pixel:
 	lda	(INL),Y			; get sprite colors		; 5
 	iny				; increment sprite pointer	; 2
diff --git a/interlace_demo/sprites.s b/interlace_demo/sprites.s
index 8098d8e6..b18da715 100644
--- a/interlace_demo/sprites.s
+++ b/interlace_demo/sprites.s
@@ -232,11 +232,12 @@ display_loop:
 	;  -31	-- move ship
 	;  -17  -- move fire
 	; -436	-- draw fire
+	; -335	-- draw asteroid
 	;  -61  -- keypress
 	;  -33	-- handle fire press
 	;   -8  -- loop
 	;=======
-	; 1147
+	; 812
 
 	;================
 	; erase old ship
@@ -589,6 +590,28 @@ no_draw_fire:
 
 done_draw_fire:
 
+
+	;=====================
+	; draw the asteroid
+
+	lda	#$0			; 2
+	sta	DRAW_PAGE		; 3
+
+	lda	#<asteroid_p1		; 2
+	sta	INL			; 3
+	lda	#>asteroid_p1		; 2
+	sta	INH			; 3
+	lda	#30			; 2
+	sta	SPRITE_XPOS		; 3
+	lda	#12			; 2
+	sta	SPRITE_YPOS		; 3
+	jsr	put_sprite		; 6+304
+					;======
+					; 335
+
+
+
+
 pad_time:
 
 
@@ -610,13 +633,12 @@ pad_time:
 
 wait_loop:
 
-	; Try X=37 Y=6 cycles=1147
-
+	; Try X=161 Y=1 cycles=812
 ;	nop
 ;	nop
 
-	ldy	#6							; 2
-loop1:	ldx	#37							; 2
+	ldy	#1							; 2
+loop1:	ldx	#161							; 2
 loop2:	dex								; 2
 	bne	loop2							; 2nt/3
 	dey								; 2
@@ -1060,3 +1082,5 @@ ship_sprite:
 	; l13:
 	.byte	$00,$00,$00,$ff,$ff,$77,$ff
 
+
+.include	"asteroid.inc"