diff --git a/build.sh b/build.sh
index cbc6e60..f0e845a 100755
--- a/build.sh
+++ b/build.sh
@@ -16,8 +16,8 @@ then
 	clang-format -i src/uxn.c
 	clang-format -i src/devices/screen.h
 	clang-format -i src/devices/screen.c
-	clang-format -i src/devices/apu.h
-	clang-format -i src/devices/apu.c
+	clang-format -i src/devices/audio.h
+	clang-format -i src/devices/audio.c
 	clang-format -i src/devices/file.h
 	clang-format -i src/devices/file.c
 	clang-format -i src/devices/mouse.h
@@ -62,7 +62,7 @@ fi
 
 echo "Building.."
 ${CC} ${CFLAGS} src/uxnasm.c -o bin/uxnasm
-${CC} ${CFLAGS} ${CORE} src/devices/file.c src/devices/mouse.c src/devices/controller.c src/devices/screen.c src/devices/apu.c src/uxnemu.c ${UXNEMU_LDFLAGS} -o bin/uxnemu
+${CC} ${CFLAGS} ${CORE} src/devices/file.c src/devices/mouse.c src/devices/controller.c src/devices/screen.c src/devices/audio.c src/uxnemu.c ${UXNEMU_LDFLAGS} -o bin/uxnemu
 ${CC} ${CFLAGS} ${CORE} src/devices/file.c src/uxncli.c -o bin/uxncli
 
 if [ -d "$HOME/bin" ]
diff --git a/mkfile b/mkfile
index ef30cda..8a010b5 100644
--- a/mkfile
+++ b/mkfile
@@ -6,7 +6,7 @@ ROM=${USM:%.tal=%.rom}
 CFLAGS=$CFLAGS -D__plan9__ -I/sys/include/npe -I/sys/include/npe/SDL2
 HFILES=\
 	/sys/include/npe/stdio.h\
-	src/devices/apu.h\
+	src/devices/audio.h\
 	src/devices/file.h\
 	src/devices/screen.h\
 	src/uxn.h\
@@ -35,13 +35,13 @@ bin/uxncli: file.$O uxncli.$O uxn.$O
 bin/uxnasm: uxnasm.$O
 	$LD $LDFLAGS -o $target $prereq
 
-bin/uxnemu: uxnemu.$O apu.$O file.$O screen.$O uxn.$O
+bin/uxnemu: uxnemu.$O audio.$O file.$O screen.$O uxn.$O
 	$LD $LDFLAGS -o $target $prereq
 
 (uxnasm|uxncli|uxnemu|uxn)\.$O:R: src/\1.c
 	$CC $CFLAGS -Isrc -o $target src/$stem1.c
 
-(apu|file|screen)\.$O:R: src/devices/\1.c
+(audio|file|screen)\.$O:R: src/devices/\1.c
 	$CC $CFLAGS -Isrc -o $target src/devices/$stem1.c
 
 nuke:V: clean
diff --git a/src/devices/apu.c b/src/devices/audio.c
similarity index 89%
rename from src/devices/apu.c
rename to src/devices/audio.c
index 9c55f06..8d71220 100644
--- a/src/devices/apu.c
+++ b/src/devices/audio.c
@@ -1,5 +1,5 @@
 #include "../uxn.h"
-#include "apu.h"
+#include "audio.h"
 
 /*
 Copyright (c) 2021 Devine Lu Linvega
@@ -23,10 +23,12 @@ static Uint32 advances[12] = {
 	0xb504f, 0xbfc88, 0xcb2ff, 0xd7450, 0xe411f, 0xf1a1c
 };
 
+Audio audio[POLYPHONY];
+
 /* clang-format on */
 
 static Sint32
-envelope(Apu *c, Uint32 age)
+envelope(Audio *c, Uint32 age)
 {
 	if(!c->r) return 0x0888;
 	if(age < c->a) return 0x0888 * age / c->a;
@@ -38,7 +40,7 @@ envelope(Apu *c, Uint32 age)
 }
 
 int
-apu_render(Apu *c, Sint16 *sample, Sint16 *end)
+audio_render(Audio *c, Sint16 *sample, Sint16 *end)
 {
 	Sint32 s;
 	if(!c->advance || !c->period) return 0;
@@ -57,12 +59,12 @@ apu_render(Apu *c, Sint16 *sample, Sint16 *end)
 		*sample++ += s * c->volume[0] / 0x180;
 		*sample++ += s * c->volume[1] / 0x180;
 	}
-	if(!c->advance) apu_finished_handler(c);
+	if(!c->advance) audio_finished_handler(c);
 	return 1;
 }
 
 void
-apu_start(Apu *c, Uint16 adsr, Uint8 pitch)
+audio_start(Audio *c, Uint16 adsr, Uint8 pitch)
 {
 	if(pitch < 108 && c->len)
 		c->advance = advances[pitch % 12] >> (8 - pitch / 12);
@@ -83,7 +85,7 @@ apu_start(Apu *c, Uint16 adsr, Uint8 pitch)
 }
 
 Uint8
-apu_get_vu(Apu *c)
+audio_get_vu(Audio *c)
 {
 	int i;
 	Sint32 sum[2] = {0, 0};
diff --git a/src/devices/apu.h b/src/devices/audio.h
similarity index 71%
rename from src/devices/apu.h
rename to src/devices/audio.h
index 019e6e1..288b291 100644
--- a/src/devices/apu.h
+++ b/src/devices/audio.h
@@ -13,6 +13,7 @@ WITH REGARD TO THIS SOFTWARE.
 typedef signed int Sint32;
 
 #define SAMPLE_FREQUENCY 44100
+#define POLYPHONY 4
 
 typedef struct {
 	Uint8 *addr;
@@ -20,9 +21,11 @@ typedef struct {
 	Uint16 i, len;
 	Sint8 volume[2];
 	Uint8 pitch, repeat;
-} Apu;
+} Audio;
 
-int apu_render(Apu *c, Sint16 *sample, Sint16 *end);
-void apu_start(Apu *c, Uint16 adsr, Uint8 pitch);
-Uint8 apu_get_vu(Apu *c);
-void apu_finished_handler(Apu *c);
+extern Audio audio[POLYPHONY];
+
+int audio_render(Audio *c, Sint16 *sample, Sint16 *end);
+void audio_start(Audio *c, Uint16 adsr, Uint8 pitch);
+Uint8 audio_get_vu(Audio *c);
+void audio_finished_handler(Audio *c);
\ No newline at end of file
diff --git a/src/devices/screen.c b/src/devices/screen.c
index bd1e490..0406595 100644
--- a/src/devices/screen.c
+++ b/src/devices/screen.c
@@ -45,8 +45,7 @@ screen_write(Screen *p, Layer *layer, Uint16 x, Uint16 y, Uint8 color)
 {
 	if(x < p->width && y < p->height) {
 		Uint32 i = x + y * p->width;
-		Uint8 prev = layer->pixels[i];
-		if(color != prev) {
+		if(color != layer->pixels[i]) {
 			layer->pixels[i] = color;
 			layer->changed = 1;
 		}
diff --git a/src/uxnemu.c b/src/uxnemu.c
index 3d76674..a852271 100644
--- a/src/uxnemu.c
+++ b/src/uxnemu.c
@@ -9,7 +9,7 @@
 #pragma clang diagnostic ignored "-Wtypedef-redefinition"
 #include <SDL.h>
 #include "devices/screen.h"
-#include "devices/apu.h"
+#include "devices/audio.h"
 #include "devices/file.h"
 #include "devices/controller.h"
 #include "devices/mouse.h"
@@ -30,7 +30,6 @@ WITH REGARD TO THIS SOFTWARE.
 #define WIDTH 64 * 8
 #define HEIGHT 40 * 8
 #define PAD 4
-#define POLYPHONY 4
 #define BENCH 0
 
 static SDL_Window *gWindow;
@@ -41,7 +40,6 @@ static SDL_Rect gRect;
 
 /* devices */
 
-static Apu apu[POLYPHONY];
 static Device *devsystem, *devscreen, *devmouse, *devctrl, *devaudio0, *devconsole;
 static Uint8 zoom = 1;
 static Uint32 stdin_event, audio0_event;
@@ -68,17 +66,17 @@ audio_callback(void *u, Uint8 *stream, int len)
 	Sint16 *samples = (Sint16 *)stream;
 	SDL_memset(stream, 0, len);
 	for(i = 0; i < POLYPHONY; ++i)
-		running += apu_render(&apu[i], samples, samples + len / 2);
+		running += audio_render(&audio[i], samples, samples + len / 2);
 	if(!running)
 		SDL_PauseAudioDevice(audio_id, 1);
 	(void)u;
 }
 
 void
-apu_finished_handler(Apu *c)
+audio_finished_handler(Audio *c)
 {
 	SDL_Event event;
-	event.type = audio0_event + (c - apu);
+	event.type = audio0_event + (c - audio);
 	SDL_PushEvent(&event);
 }
 
@@ -212,10 +210,10 @@ console_deo(Device *d, Uint8 port)
 static Uint8
 audio_dei(Device *d, Uint8 port)
 {
-	Apu *c = &apu[d - devaudio0];
+	Audio *c = &audio[d - devaudio0];
 	if(!audio_id) return d->dat[port];
 	switch(port) {
-	case 0x4: return apu_get_vu(c);
+	case 0x4: return audio_get_vu(c);
 	case 0x2: poke16(d->dat, 0x2, c->i); /* fall through */
 	default: return d->dat[port];
 	}
@@ -224,7 +222,7 @@ audio_dei(Device *d, Uint8 port)
 static void
 audio_deo(Device *d, Uint8 port)
 {
-	Apu *c = &apu[d - devaudio0];
+	Audio *c = &audio[d - devaudio0];
 	if(!audio_id) return;
 	if(port == 0xf) {
 		SDL_LockAudioDevice(audio_id);
@@ -233,7 +231,7 @@ audio_deo(Device *d, Uint8 port)
 		c->volume[0] = d->dat[0xe] >> 4;
 		c->volume[1] = d->dat[0xe] & 0xf;
 		c->repeat = !(d->dat[0xf] & 0x80);
-		apu_start(c, peek16(d->dat, 0x8), d->dat[0xf] & 0x7f);
+		audio_start(c, peek16(d->dat, 0x8), d->dat[0xf] & 0x7f);
 		SDL_UnlockAudioDevice(audio_id);
 		SDL_PauseAudioDevice(audio_id, 0);
 	}