diff --git a/doc/notes.txt b/doc/notes.txt
index 0ea3b65f..212e59b8 100644
--- a/doc/notes.txt
+++ b/doc/notes.txt
@@ -85,6 +85,7 @@ TODO:
 - live coding URL
 - memory viewer: ROM/RAM/VRAM/etc
 - resize memory browser when split resize
+- preroll the emulator so optimizer does its thing before loading rom
 
 
 WEB WORKER FORMAT
diff --git a/presets/astrocade/cosmic.c b/presets/astrocade/cosmic.c
index 55804765..3133a28c 100644
--- a/presets/astrocade/cosmic.c
+++ b/presets/astrocade/cosmic.c
@@ -165,24 +165,24 @@ void draw_bcd_word(word bcd, byte x, byte y, byte op) {
 }
 
 // add two 16-bit BCD values
-word bcd_add(word a, word b) {
+word bcd_add(word a, word b) __naked {
   a; b; // to avoid warning
 __asm
-        ld      hl,#4
-        add     hl,sp
-        ld      iy,#2
-        add     iy,sp
-        ld      a,0 (iy)
-        add     a, (hl)
-        daa
-        ld      c,a
-        ld      a,1 (iy)
-        inc     hl
-        adc     a, (hl)
-        daa
-        ld      b,a
-        ld      l, c
-        ld      h, b
+ 	push	ix
+ 	ld	ix,#0
+	add	ix,sp
+ 	ld	a,4 (ix)
+ 	add	a, 6 (ix)
+	daa
+	ld	c,a
+ 	ld	a,5 (ix)
+ 	adc	a, 7 (ix)
+	daa
+ 	ld	b,a
+ 	ld	l, c
+ 	ld	h, b
+	pop	ix
+ 	ret
 __endasm;
 }
 
diff --git a/presets/coleco/common.c b/presets/coleco/common.c
index 23068866..f4d787b1 100644
--- a/presets/coleco/common.c
+++ b/presets/coleco/common.c
@@ -87,24 +87,24 @@ void draw_bcd_word(byte x, byte y, word bcd) {
 }
 
 // add two 16-bit BCD values
-word bcd_add(word a, word b) {
+word bcd_add(word a, word b) __naked {
   a; b; // to avoid warning
 __asm
-        ld      hl,#4
-        add     hl,sp
-        ld      iy,#2
-        add     iy,sp
-        ld      a,0 (iy)
-        add     a, (hl)
-        daa
-        ld      c,a
-        ld      a,1 (iy)
-        inc     hl
-        adc     a, (hl)
-        daa
-        ld      b,a
-        ld      l, c
-        ld      h, b
+ 	push	ix
+ 	ld	ix,#0
+	add	ix,sp
+ 	ld	a,4 (ix)
+ 	add	a, 6 (ix)
+	daa
+	ld	c,a
+ 	ld	a,5 (ix)
+ 	adc	a, 7 (ix)
+	daa
+ 	ld	b,a
+ 	ld	l, c
+ 	ld	h, b
+	pop	ix
+ 	ret
 __endasm;
 }
 
diff --git a/presets/galaxian-scramble/shoot2.c b/presets/galaxian-scramble/shoot2.c
index 9ec2ed39..6502e4bc 100644
--- a/presets/galaxian-scramble/shoot2.c
+++ b/presets/galaxian-scramble/shoot2.c
@@ -185,24 +185,24 @@ void draw_bcd_word(byte x, byte y, word bcd) {
 }
 
 // add two 16-bit BCD values
-word bcd_add(word a, word b) {
+word bcd_add(word a, word b) __naked {
   a; b; // to avoid warning
 __asm
-        ld      hl,#4
-        add     hl,sp
-        ld      iy,#2
-        add     iy,sp
-        ld      a,0 (iy)
-        add     a, (hl)
-        daa
-        ld      c,a
-        ld      a,1 (iy)
-        inc     hl
-        adc     a, (hl)
-        daa
-        ld      b,a
-        ld      l, c
-        ld      h, b
+ 	push	ix
+ 	ld	ix,#0
+	add	ix,sp
+ 	ld	a,4 (ix)
+ 	add	a, 6 (ix)
+	daa
+	ld	c,a
+ 	ld	a,5 (ix)
+ 	adc	a, 7 (ix)
+	daa
+ 	ld	b,a
+ 	ld	l, c
+ 	ld	h, b
+	pop	ix
+ 	ret
 __endasm;
 }
 
diff --git a/presets/mw8080bw/game2.c b/presets/mw8080bw/game2.c
index def85add..d004d657 100644
--- a/presets/mw8080bw/game2.c
+++ b/presets/mw8080bw/game2.c
@@ -181,24 +181,24 @@ void draw_bcd_word(word bcd, byte x, byte y) {
 }
 
 // add two 16-bit BCD values
-word bcd_add(word a, word b) {
+word bcd_add(word a, word b) __naked {
   a; b; // to avoid warning
 __asm
-        ld      hl,#4
-        add     hl,sp
-        ld      iy,#2
-        add     iy,sp
-        ld      a,0 (iy)
-        add     a, (hl)
-        daa
-        ld      c,a
-        ld      a,1 (iy)
-        inc     hl
-        adc     a, (hl)
-        daa
-        ld      b,a
-        ld      l, c
-        ld      h, b
+ 	push	ix
+ 	ld	ix,#0
+	add	ix,sp
+ 	ld	a,4 (ix)
+ 	add	a, 6 (ix)
+	daa
+	ld	c,a
+ 	ld	a,5 (ix)
+ 	adc	a, 7 (ix)
+	daa
+ 	ld	b,a
+ 	ld	l, c
+ 	ld	h, b
+	pop	ix
+ 	ret
 __endasm;
 }