diff --git a/graphics/hgr/tiny_triangles/mod9.s b/graphics/hgr/tiny_triangles/mod9.s
index c27ceeea..1337ee1d 100644
--- a/graphics/hgr/tiny_triangles/mod9.s
+++ b/graphics/hgr/tiny_triangles/mod9.s
@@ -1,3 +1,8 @@
+; Sort of plotting (X^Y) % 9
+; but in hires
+
+; by Vince `deater` Weaver <vince@deater.net>
+
 GBASL		= $26
 GBASH		= $27
 HGRPAGE		= $E6
@@ -7,46 +12,55 @@ HGR_Y		= $E2
 HGR_COLOR	= $E4
 HGR_HORIZ	= $E5
 
+OUR_MASK	= $FB
+YY		= $FC
 SAVEX		= $FD
 TEMP		= $FE
 OLD		= $FF
 
-PAGE0	= $C054
-PAGE1	= $C055
+PAGE0		= $C054
+PAGE1		= $C055
 
-COLORTBL	=	$F6F6
+COLORTBL	= $F6F6
 
-HGR	= $F3E2
-HGR2	= $F3D8
-HCLR	= $F3F2
-HPOSN	= $F411
-HPLOT0  = $F457                 ;; plot at (Y,X), (A)
-HPLOT1	= $F45A
-COLOR_SHIFT = $F47E
+HGR2		= $F3D8
+HGR		= $F3E2
+HCLR		= $F3F2
+HPOSN		= $F411
+HPLOT0  	= $F457		; plot at (Y,X), (A)
+HPLOT1		= $F45A		; skip the HPOSN call
+COLOR_SHIFT	= $F47E		; shift color for odd/even Y (0..7 or 7..13)
+MOVE_RIGHT	= $F48A		; move next plot location one to the right
 
-MOVE_RIGHT = $F48A
-
-HCOLOR1	= $F6F0
-WAIT    = $FCA8                 ;; delay 1/2(26+27A+5A^2) us
+HCOLOR1		= $F6F0		; set HGR_COLOR to value in X
+WAIT		= $FCA8		; delay 1/2(26+27A+5A^2) us
 
 
 mod9_lookup = $1000
 
 
+	;==============================
+	; mod9 start
+	;==============================
 mod9_start:
-	jsr	make_mod9_lookup
+	jsr	make_mod9_lookup	; setup modulo 9 lookup table
+					; could inline it here
 
 	jsr	HGR2		; clear page1
 				; A is 0 after
 
-tiny_yloop:
+	sta	OUR_MASK
+
+mod9_reset:
+	ldy	#0
+	sty	YY
+
+mod9_yloop:
 
 	ldy	#0
 	ldx	#0		; XX = 0
-yy_smc:
-	lda	#0		; Y co-ord
-
-	jsr	HPOSN		; plot at (Y,X), (A)
+	lda	YY		; Y co-ord
+	jsr	HPOSN		; set cursor position to (Y,X), (A)
 
 	ldx	#0
 
@@ -54,30 +68,41 @@ tiny_xloop:
 
 	stx	SAVEX
 
-;	jsr	HPLOT1
-
 ;===============here
 
 	txa
-	eor	yy_smc+1
+	eor	YY
 	tax
 	lda	mod9_lookup,X
 
 
+;=================
 
-blurgh:
-	and	#$1
+	ldx	OUR_MASK
+	bne	weird_pattern
+
+	cmp	#0
+	beq     store_color
+
+        lda     #3
+store_color:
+	jmp	color_ready
 
 
+
+
+weird_pattern:
+
+	and	OUR_MASK
+
+color_ready:
 	tax
 
 	tya
 	lsr			; check even or odd
 	php
 
-;	jsr	HCOLOR1
 	lda	COLORTBL,X
-;	sta	HGR_COLOR
 	sta	HGR_BITS
 
 	plp
@@ -87,33 +112,50 @@ blurgh:
 
 no_shift:
 
-;	beq	store_color
+	jsr	HPLOT1		; plot at current position
 
-;	lda	#$7f
-;store_color:
-;	sta	HGR_COLOR
+	jsr	MOVE_RIGHT	; move current position right (trashes A)
 
+	ldx	SAVEX		; restore X
 
-	jsr	HPLOT1
-	jsr	MOVE_RIGHT	; trashes A
-
-	ldx	SAVEX
+	;==================================
 
 	inx
-	bne	tiny_xloop
+	bne	tiny_xloop	; repeat until X=256
 
-	inc	yy_smc+1
-	ldy	yy_smc+1
+	;==================================
+
+	inc	YY		; repeat until Y=192
+	ldy	YY
 	cpy	#192
-	bne	tiny_yloop
+	bne	mod9_yloop
 
-	inc	blurgh+1
-	ldy	#0
-	sty	yy_smc+1
-	beq	tiny_yloop
+	;==================================
+
+change_pattern:
+	inc	OUR_MASK	; change pattern
+	lda	OUR_MASK
+
+check_4:
+	cmp	#4
+	bne	check_9
+	lda	#8
+	sta	OUR_MASK
+
+check_9:
+	cmp	#9
+	bne	done_check
+	lda	#0
+	sta	OUR_MASK
+
+done_check:
+	jmp	mod9_reset
 
 
 
+	;=============================
+	; setup the mod9 lookup table
+	;=============================
 make_mod9_lookup:
 	ldy	#0
 m9_xreset:
@@ -121,11 +163,14 @@ m9_xreset:
 m9_loop:
 	txa
 	sta	mod9_lookup,Y
+
 	iny
 	beq	m9_done
+
 	inx
 	cpx	#9
 	beq	m9_xreset
 	bne	m9_loop
+
 m9_done:
 	rts