diff --git a/build.sh b/build.sh
index 54028c9..a7b2e56 100755
--- a/build.sh
+++ b/build.sh
@@ -20,5 +20,5 @@ cc -std=c89 -DDEBUG -Wall -Wno-unknown-pragmas -Wpedantic -Wshadow -Wextra -Werr
 # cc uxn.c emulator.c -std=c89 -Os -DNDEBUG -g0 -s -Wall -Wno-unknown-pragmas -L/usr/local/lib -lSDL2 -o bin/emulator
 
 # run
-./bin/assembler examples/gui.shapes.usm bin/boot.rom
+./bin/assembler examples/dev.mouse.usm bin/boot.rom
 ./bin/emulator bin/boot.rom
diff --git a/emulator.c b/emulator.c
index c8e858b..8dc56fe 100644
--- a/emulator.c
+++ b/emulator.c
@@ -253,30 +253,31 @@ init(void)
 }
 
 void
-domouse(SDL_Event *event)
+domouse(Uxn *u, SDL_Event *event)
 {
 	Uint8 flag = 0x00;
+	Uint16 addr = 0xff50; /* TODO: get dynamically */
 	Uint16 x = clamp(event->motion.x / ZOOM - PAD * 8, 0, HOR * 8 - 1);
 	Uint16 y = clamp(event->motion.y / ZOOM - PAD * 8, 0, VER * 8 - 1);
-	devmouse->mem[0] = (x >> 8) & 0xff;
-	devmouse->mem[1] = x & 0xff;
-	devmouse->mem[2] = (y >> 8) & 0xff;
-	devmouse->mem[3] = y & 0xff;
-	devmouse->mem[5] = 0x00;
+	u->ram.dat[addr + 0] = (x >> 8) & 0xff;
+	u->ram.dat[addr + 1] = x & 0xff;
+	u->ram.dat[addr + 2] = (y >> 8) & 0xff;
+	u->ram.dat[addr + 3] = y & 0xff;
+	u->ram.dat[addr + 5] = 0x00;
 	switch(event->button.button) {
 	case SDL_BUTTON_LEFT: flag = 0x01; break;
 	case SDL_BUTTON_RIGHT: flag = 0x10; break;
 	}
 	switch(event->type) {
 	case SDL_MOUSEBUTTONUP:
-		setflag(&devmouse->mem[4], flag, 0);
+		setflag(&u->ram.dat[addr + 4], flag, 0);
 		break;
 	case SDL_MOUSEBUTTONDOWN:
-		setflag(&devmouse->mem[4], flag, 1);
-		if(flag == 0x01 && getflag(&devmouse->mem[4], 0x10))
-			devmouse->mem[5] = 0x01;
-		if(flag == 0x10 && getflag(&devmouse->mem[4], 0x01))
-			devmouse->mem[5] = 0x10;
+		setflag(&u->ram.dat[addr + 4], flag, 1);
+		if(flag == 0x01 && getflag(&u->ram.dat[addr + 4], 0x10))
+			u->ram.dat[addr + 5] = 0x01;
+		if(flag == 0x10 && getflag(&u->ram.dat[addr + 4], 0x01))
+			u->ram.dat[addr + 5] = 0x10;
 		break;
 	}
 }
@@ -325,19 +326,23 @@ doctrl(SDL_Event *event, int z)
 #pragma mark - Devices
 
 Uint8
-console_poke(Uint8 *m, Uint8 b0, Uint8 b1)
+console_poke(Uint8 *m, Uint16 ptr, Uint8 b0, Uint8 b1)
 {
 	printf("%c", b1);
 	fflush(stdout);
+	(void)m;
+	(void)ptr;
+	(void)b0;
 	return b1;
 }
 
 Uint8
-screen_poke(Uint8 *m, Uint8 b0, Uint8 b1)
+screen_poke(Uint8 *m, Uint16 ptr, Uint8 b0, Uint8 b1)
 {
-	if(b0 == 0x04) {
-		Uint16 x = (*(m + 2) << 8) + *(m + 3);
-		Uint16 y = (*m << 8) + *(m + 1);
+	ptr += 8;
+	if(b0 == 0x0c) {
+		Uint16 x = (m[ptr] << 8) + m[ptr + 1];
+		Uint16 y = (m[ptr + 2] << 8) + m[ptr + 3];
 		paintpixel(b1 >> 4 & 0xf ? screen.fg : screen.bg, x, y, b1 & 0xf);
 		screen.reqdraw = 1;
 	}
@@ -345,16 +350,30 @@ screen_poke(Uint8 *m, Uint8 b0, Uint8 b1)
 }
 
 Uint8
-peek1(Uint8 *m, Uint8 b0, Uint8 b1)
+sprite_poke(Uint8 *m, Uint16 ptr, Uint8 b0, Uint8 b1)
 {
-	printf("PEEK! %02x\n", b1);
+	ptr += 8;
+	if(b0 == 0x0e) {
+		Uint16 x = (m[ptr] << 8) + m[ptr + 1];
+		Uint16 y = (m[ptr + 2] << 8) + m[ptr + 3];
+		Uint16 a = (m[ptr + 4] << 8) + m[ptr + 5];
+		Uint8 source = (b1 >> 4) & 0xf;
+		Uint8 *layer = source % 2 ? screen.fg : screen.bg;
+		if(source / 2)
+			paintchr(layer, x, y, &m[a]);
+		else
+			painticn(layer, x, y, &m[a], b1 & 0xf);
+		screen.reqdraw = 1;
+	}
 	return b1;
 }
 
 Uint8
-poke1(Uint8 *m, Uint8 b0, Uint8 b1)
+ppnil(Uint8 *m, Uint16 ptr, Uint8 b0, Uint8 b1)
 {
-	printf("POKE! %02x\n", b1);
+	(void)m;
+	(void)ptr;
+	(void)b0;
 	return b1;
 }
 
@@ -376,37 +395,6 @@ consolew(Device *d, Memory *m, Uint8 b)
 	return 0;
 }
 
-Uint8
-screenr(Device *d, Memory *m, Uint8 b)
-{
-	loadtheme(m->dat + 0xfff0);
-	switch(b) {
-	case 0: return (HOR * 8 >> 8) & 0xff;
-	case 1: return HOR * 8 & 0xff;
-	case 2: return (VER * 8 >> 8) & 0xff;
-	case 3: return VER * 8 & 0xff;
-	}
-	(void)m;
-	return d->mem[b];
-}
-
-Uint8
-screenw(Device *d, Memory *m, Uint8 b)
-{
-	d->mem[d->ptr++] = b;
-	if(d->ptr > 4) {
-		Uint16 x = (d->mem[2] << 8) + d->mem[3];
-		Uint16 y = (d->mem[0] << 8) + d->mem[1];
-		Uint8 clr = d->mem[4] & 0xf;
-		Uint8 layer = d->mem[4] >> 4 & 0xf;
-		paintpixel(layer ? screen.fg : screen.bg, x, y, clr);
-		screen.reqdraw = 1;
-		d->ptr = 0;
-	}
-	(void)m;
-	return 0;
-}
-
 Uint8
 spritew(Device *d, Memory *m, Uint8 b)
 {
@@ -449,7 +437,7 @@ start(Uxn *u)
 			case SDL_QUIT: quit(); break;
 			case SDL_MOUSEBUTTONUP:
 			case SDL_MOUSEBUTTONDOWN:
-			case SDL_MOUSEMOTION: domouse(&event); break;
+			case SDL_MOUSEMOTION: domouse(u, &event); break;
 			case SDL_TEXTINPUT: dotext(&event); break;
 			case SDL_KEYDOWN: doctrl(&event, 1); break;
 			case SDL_KEYUP: doctrl(&event, 0); break;
@@ -479,12 +467,17 @@ main(int argc, char **argv)
 	if(!init())
 		return error("Init", "Failed");
 
-	devconsole = portuxn(&u, "console", defaultrw, consolew, peek1, console_poke);
-	devscreen = portuxn(&u, "screen", screenr, screenw, peek1, screen_poke);
-	devsprite = portuxn(&u, "sprite", screenr, spritew, peek1, poke1);
-	devcontroller = portuxn(&u, "controller", defaultrw, defaultrw, peek1, poke1);
-	devkey = portuxn(&u, "key", defaultrw, consolew, peek1, poke1);
-	devmouse = portuxn(&u, "mouse", defaultrw, defaultrw, peek1, poke1);
+	devconsole = portuxn(&u, "console", defaultrw, consolew, ppnil, console_poke);
+	devscreen = portuxn(&u, "screen", defaultrw, defaultrw, ppnil, screen_poke);
+	devsprite = portuxn(&u, "sprite", defaultrw, spritew, ppnil, sprite_poke);
+	devcontroller = portuxn(&u, "controller", defaultrw, defaultrw, ppnil, ppnil);
+	devkey = portuxn(&u, "key", defaultrw, consolew, ppnil, ppnil);
+	devmouse = portuxn(&u, "mouse", defaultrw, defaultrw, ppnil, ppnil);
+
+	u.ram.dat[0xff10] = (HOR * 8 >> 8) & 0xff;
+	u.ram.dat[0xff11] = HOR * 8 & 0xff;
+	u.ram.dat[0xff12] = (VER * 8 >> 8) & 0xff;
+	u.ram.dat[0xff13] = VER * 8 & 0xff;
 
 	start(&u);
 	quit();
diff --git a/examples/blank.usm b/examples/blank.usm
index 7d679c2..98d5540 100644
--- a/examples/blank.usm
+++ b/examples/blank.usm
@@ -1,11 +1,18 @@
 ( blank )
 
-:dev/r fff8 ( std read port )
-:dev/w fff9 ( std write port )
+&Console { pad 8 stdio 1 }
+&Screen  { width 2 height 2 pad 4 y 2 x 2 color 1 }
+&Sprite  { pad 8 y 2 x 2 addr 2 color 1 }
+&Mouse   { x 2 y 2 state 1 chord 1 }
 
 |0100 @RESET BRK
 |c000 @FRAME BRK 
 |d000 @ERROR BRK 
 
+|FF00 ;dev/console Console
+|FF10 ;dev/screen  Screen
+|FF20 ;dev/sprite  Sprite
+|FF50 ;dev/mouse   Mouse
+
 |FFF0 [ f2ac 35bb 2b53 ] ( palette )
 |FFFA .RESET .FRAME .ERROR
diff --git a/examples/devchord.usm b/examples/dev.chord.usm
similarity index 100%
rename from examples/devchord.usm
rename to examples/dev.chord.usm
diff --git a/examples/devconsole.usm b/examples/dev.console.usm
similarity index 91%
rename from examples/devconsole.usm
rename to examples/dev.console.usm
index 675c1ce..cc057b7 100644
--- a/examples/devconsole.usm
+++ b/examples/dev.console.usm
@@ -1,6 +1,6 @@
 ( hello world )
 
-&Console { stdio 1 }
+&Console { pad 8 stdio 1 }
 
 |0100 @RESET 
 	
diff --git a/examples/devmouse.usm b/examples/dev.mouse.usm
similarity index 83%
rename from examples/devmouse.usm
rename to examples/dev.mouse.usm
index ed77f3b..ded4cad 100644
--- a/examples/devmouse.usm
+++ b/examples/dev.mouse.usm
@@ -1,45 +1,37 @@
 ( mouse )
 
-:dev/r fff8 ( std read port )
-:dev/w fff9 ( std write port )
+&Screen { width 2 height 2 pad 4 y 2 x 2 color 1 }
+&Sprite { pad 8 y 2 x 2 addr 2 color 1 }
+&Mouse  { x 2 y 2 state 1 chord 1 }
 
 &Point2d { x 2 y 2 }
 
-;mouse Point2d
-;cat Point2d
+;cat Point2d ;mouse Point2d
 
-;state 1 ;timer 1
+;timer 1
 
 |0100 @RESET 
-	
-	#01 =dev/r ( set dev/read screen )
 
 	( position cat )
-	#00 IOR2 #0002 DIV2 =cat.x 
-	#02 IOR2 #0038 SUB2 =cat.y
-
-	#05 =dev/r ( set dev/read mouse )
-	#02 =dev/w ( set dev/write to sprite ) 
-	
+	~dev/screen.width #0002 DIV2 =cat.x 
+	~dev/screen.height #0038 SUB2 =cat.y
 	( draw polycat )
 	,draw-polycat JSR
 
 BRK
 
 |c000 @FRAME
-
+	
 	( clear last cursor )
 	#10 ,clear_icn ~mouse.x ~mouse.y ,draw-sprite JSR
 	( record mouse positions )
-	#00 IOR2 =mouse.x #02 IOR2 =mouse.y
-	( record mouse state )
-	#04 IOR #11 ADD =state
+	~dev/mouse.x =mouse.x ~dev/mouse.y =mouse.y
 	( detect click )
-	#04 IOR #01 NEQ ,no-click ROT JMP? POP2
+	~dev/mouse.state #01 NEQ ,no-click ROT JMP? POP2
 		#50 =timer
 	@no-click
 	( draw mouse )
-	~state ,cursor_icn ~mouse.x ~mouse.y ,draw-sprite JSR
+	~dev/mouse.state #11 ADD ,cursor_icn ~mouse.x ~mouse.y ,draw-sprite JSR
 	( animate )
 	,animate-polycat JSR
 	( update last pos )
@@ -99,17 +91,17 @@ RTS
 RTS
 
 @draw-sprite
-	IOW2 ( y byte )
-	IOW2 ( x byte )
-	IOW2 ( sprite address )
-	IOW ( layer-color )
+	=dev/sprite.x
+	=dev/sprite.y
+	=dev/sprite.addr
+	=dev/sprite.color
 	RTS
 
 @draw-sprite-chr
-	IOW2 ( y byte )
-	IOW2 ( x byte )
-	IOW2 ( sprite address )
-	#20 IOW ( layer-color )
+	=dev/sprite.x
+	=dev/sprite.y
+	=dev/sprite.addr
+	#20 =dev/sprite.color
 	RTS
 
 @clear_icn   [ 0000 0000 0000 0000 ]
@@ -132,6 +124,10 @@ RTS
 	c0f0 f0e0 e080 8000 c0f1 faf9 fef8 b000
 ]
 
+|FF10 ;dev/screen Screen
+|FF20 ;dev/sprite Sprite
+|FF50 ;dev/mouse  Mouse
+
 |d000 @ERROR BRK 
 |FFF0 [ 0f85 0fd5 0fb5 ] ( palette )
 |FFFA .RESET .FRAME .ERROR
diff --git a/examples/dev.screen.usm b/examples/dev.screen.usm
new file mode 100644
index 0000000..14fe7b1
--- /dev/null
+++ b/examples/dev.screen.usm
@@ -0,0 +1,40 @@
+( screen )
+
+&Screen { width 2 height 2 pad 4 x 2 y 2 color 1 }
+
+;centerx 2 ;centery 2 ;i 2
+
+|0100 @RESET 
+
+	( find screen center )
+	~dev/screen.width #0002 DIV2 =centerx
+	~dev/screen.height #0002 DIV2 =centery
+
+	( draw hor line )
+	#0000 =i
+	~centery =dev/screen.y
+	@draw-hor
+		#03 ~i =dev/screen.x =dev/screen.color
+		~i #0002 ADD2 =i ( increment )
+	~i ~dev/screen.width LTH2 ,draw-hor ROT JMP? POP2
+
+	( draw ver line )
+	#0000 =i
+	~centerx =dev/screen.x
+	@draw-ver
+		#03 ~i =dev/screen.y =dev/screen.color
+		~i #0002 ADD2 =i ( increment )
+	~i ~dev/screen.width LTH2 ,draw-ver ROT JMP? POP2
+
+	( draw pixel in the middle )
+	#01 ~centerx ~centery =dev/screen.y =dev/screen.x =dev/screen.color
+
+BRK
+
+|c000 @FRAME BRK
+|d000 @ERROR BRK 
+
+|FF10 ;dev/screen Screen
+
+|FFF0 [ f0ac f0bb f053 ] ( palette )
+|FFFA .RESET .FRAME .ERROR ( vectors )
diff --git a/examples/devscreen.usm b/examples/devscreen.usm
deleted file mode 100644
index 97505d6..0000000
--- a/examples/devscreen.usm
+++ /dev/null
@@ -1,45 +0,0 @@
-( screen )
-
-:dev/r fff8 ( std read port )
-:dev/w fff9 ( std write port )
-
-;centerx 2 ;centery 2 ;i 2
-
-|0100 @RESET 
-	
-	( set read/write to dev/screen )
-	#01 DUP =dev/r =dev/w 
-
-	( find screen center )
-	#00 IOR2 #0002 DIV2 =centerx
-	#02 IOR2 #0002 DIV2 =centery
-
-	( draw hor line )
-	#0000 =i
-	@draw-hor
-		#03 ~i ~centery ,draw-pixel JSR
-		~i #0002 ADD2 =i ( increment )
-	~i #00 IOR2 LTH2 ,draw-hor ROT JMP? POP2
-
-	( draw ver line )
-	#0000 =i
-	@draw-ver
-		#03 ~centerx ~i ,draw-pixel JSR
-		~i #0002 ADD2 =i ( increment )
-	~i #02 IOR2 LTH2 ,draw-ver ROT JMP? POP2
-
-	( draw pixel in the middle )
-	#01 ~centerx ~centery ,draw-pixel JSR
-
-BRK
-
-@draw-pixel 
-	IOW2 ( y short )
-	IOW2 ( x short )
-	IOW ( color byte )
-	RTS
-
-|c000 @FRAME BRK
-|d000 @ERROR BRK 
-|FFF0 [ f0ac f0bb f053 ] ( palette )
-|FFFA .RESET .FRAME .ERROR ( vectors )
diff --git a/examples/blending.usm b/examples/gui.blending.usm
similarity index 100%
rename from examples/blending.usm
rename to examples/gui.blending.usm
diff --git a/examples/gui.shapes.usm b/examples/gui.shapes.usm
index 881ffd8..15cfd19 100644
--- a/examples/gui.shapes.usm
+++ b/examples/gui.shapes.usm
@@ -1,6 +1,6 @@
 ( draw routines )
 
-&Screen { y 2 x 2 color 1 }
+&Screen { width 2 height 2 pad 4 y 2 x 2 color 1 red 1 green 1 blue 1 }
 
 ;color 1 ;x1 2 ;x2 2 ;y1 2 ;y2 2
 
@@ -53,7 +53,7 @@ RTS
 |c000 @FRAME BRK 
 |d000 @ERROR BRK 
 
-|FF08 ;dev/screen Screen
+|FF10 ;dev/screen Screen
 
 |FFF0 [ 0f0f 0fff 0ff0 ] ( palette )
 |FFFA .RESET .FRAME .ERROR ( vectors )
\ No newline at end of file
diff --git a/uxn.c b/uxn.c
index d407af5..7690ea3 100644
--- a/uxn.c
+++ b/uxn.c
@@ -18,9 +18,9 @@ WITH REGARD TO THIS SOFTWARE.
 /* clang-format off */
 void   setflag(Uint8 *a, char flag, int b) { if(b) *a |= flag; else *a &= (~flag); }
 int    getflag(Uint8 *a, char flag) { return *a & flag; }
-Uint8  devpoke8(Uxn *u, Uint8 id, Uint8 b0, Uint8 b1){ return id < u->devices ? u->dev[id].poke(&u->ram.dat[0xff00 + id * 8], b0, b1) : b1; }
-Uint8  devpeek8(Uxn *u, Uint8 id, Uint8 b0, Uint8 b1){ return id < u->devices ? u->dev[id].peek(&u->ram.dat[0xff00 + id * 8], b0, b1) : b1; }
-void   mempoke8(Uxn *u, Uint16 a, Uint8 b) { u->ram.dat[a] = a >= 0xff00 ? devpoke8(u, (a & 0xff) >> 3, (a & 0xf) % 8, b) : b; }
+Uint8  devpoke8(Uxn *u, Uint8 id, Uint8 b0, Uint8 b1){ return id < u->devices ? u->dev[id].poke(u->ram.dat, 0xff00 + id * 0x10, b0, b1) : b1; }
+Uint8  devpeek8(Uxn *u, Uint8 id, Uint8 b0, Uint8 b1){ return id < u->devices ? u->dev[id].peek(u->ram.dat, 0xff00 + id * 0x10, b0, b1) : b1; }
+void   mempoke8(Uxn *u, Uint16 a, Uint8 b) { u->ram.dat[a] = a >= 0xff00 ? devpoke8(u, (a & 0xff) >> 4, a & 0xf, b) : b; }
 Uint8  mempeek8(Uxn *u, Uint16 a) { return a >= 0xff00 ? devpeek8(u, (a & 0xff) >> 4, a & 0xf, u->ram.dat[a]) : u->ram.dat[a]; }
 void   mempoke16(Uxn *u, Uint16 a, Uint16 b) { mempoke8(u, a, b >> 8); mempoke8(u, a + 1, b); }
 Uint16 mempeek16(Uxn *u, Uint16 a) { return (mempeek8(u, a) << 8) + mempeek8(u, a + 1); }
@@ -211,7 +211,7 @@ loaduxn(Uxn *u, char *filepath)
 }
 
 Device *
-portuxn(Uxn *u, char *name, Uint8 (*rfn)(Device *, Memory *, Uint8), Uint8 (*wfn)(Device *, Memory *, Uint8), Uint8 (*pefn)(Uint8 *m, Uint8 b0, Uint8 b1), Uint8 (*pofn)(Uint8 *m, Uint8 b0, Uint8 b1))
+portuxn(Uxn *u, char *name, Uint8 (*rfn)(Device *, Memory *, Uint8), Uint8 (*wfn)(Device *, Memory *, Uint8), Uint8 (*pefn)(Uint8 *m, Uint16 ptr, Uint8 b0, Uint8 b1), Uint8 (*pofn)(Uint8 *m, Uint16 ptr, Uint8 b0, Uint8 b1))
 {
 	Device *d = &u->dev[u->devices++];
 	d->read = rfn;
diff --git a/uxn.h b/uxn.h
index 1c783f7..e670e38 100644
--- a/uxn.h
+++ b/uxn.h
@@ -35,8 +35,8 @@ typedef struct Device {
 	Uint8 ptr, mem[8];
 	Uint8 (*read)(struct Device *, Memory *, Uint8);
 	Uint8 (*write)(struct Device *, Memory *, Uint8);
-	Uint8 (*peek)(Uint8 *, Uint8, Uint8);
-	Uint8 (*poke)(Uint8 *, Uint8, Uint8);
+	Uint8 (*peek)(Uint8 *, Uint16, Uint8, Uint8);
+	Uint8 (*poke)(Uint8 *, Uint16, Uint8, Uint8);
 } Device;
 
 typedef struct {
@@ -52,4 +52,4 @@ int getflag(Uint8 *status, char flag);
 int loaduxn(Uxn *c, char *filepath);
 int bootuxn(Uxn *c);
 int evaluxn(Uxn *u, Uint16 vec);
-Device *portuxn(Uxn *u, char *name, Uint8 (*rfn)(Device *, Memory *, Uint8), Uint8 (*wfn)(Device *, Memory *, Uint8), Uint8 (*pefn)(Uint8 *, Uint8, Uint8), Uint8 (*pofn)(Uint8 *, Uint8, Uint8));
+Device *portuxn(Uxn *u, char *name, Uint8 (*rfn)(Device *, Memory *, Uint8), Uint8 (*wfn)(Device *, Memory *, Uint8), Uint8 (*pefn)(Uint8 *, Uint16, Uint8, Uint8), Uint8 (*pofn)(Uint8 *, Uint16, Uint8, Uint8));