diff --git a/build.sh b/build.sh
index 9f16aac..c3c2177 100755
--- a/build.sh
+++ b/build.sh
@@ -36,7 +36,7 @@ echo "Cleaning.."
 rm -f ./bin/uxnasm
 rm -f ./bin/uxnemu
 rm -f ./bin/uxncli
-rm -f ./bin/hypervisor.rom
+rm -f ./bin/supervisor.rom
 rm -f ./bin/boot.rom
 rm -f ./bin/asma.rom
 
@@ -106,9 +106,10 @@ then
 	cp bin/uxnemu bin/uxnasm bin/uxncli $HOME/bin/
 fi
 
-echo "Assembling(boot+hypervisor).."
+echo "Assembling(supervisor).."
+./bin/uxnasm projects/software/supervisor.tal bin/supervisor.rom
+echo "Assembling(boot).."
 ./bin/uxnasm projects/software/boot.tal bin/boot.rom
-./bin/uxnasm projects/software/hypervisor.tal bin/hypervisor.rom
 echo "Assembling(asma).."
 ./bin/uxnasm projects/software/asma.tal bin/asma.rom
 
diff --git a/projects/software/hypervisor.tal b/projects/software/supervisor.tal
similarity index 96%
rename from projects/software/hypervisor.tal
rename to projects/software/supervisor.tal
index 2cf0db1..31c1b27 100644
--- a/projects/software/hypervisor.tal
+++ b/projects/software/supervisor.tal
@@ -22,6 +22,9 @@
 %2//  { #01 SFT2 }
 %8**  { #30 SFT2 }
 
+%EADDR { #fd04 }
+%ECODE { #fd06 }
+
 ( devices )
 
 |00 @System     &vector $2 &wst      $1 &rst    $1 &eaddr  $2 &ecode  $1 &pad     $1 &r       $2 &g      $2 &b     $2 &debug  $1 &halt $1
@@ -51,7 +54,7 @@
 	;draw-cross JSR2
 	;draw-stacks JSR2
 
-	.System/eaddr DEI2 #0000 !! ;on-error JCN2
+	EADDR LDA2 #0000 !! ;on-error JCN2
 
 BRK
 
@@ -93,9 +96,9 @@ BRK
 
 	;at-txt #4f ;draw-str JSR2
 
-	.System/eaddr DEI2 #47 ;draw-short JSR2
+	EADDR LDA2 #47 ;draw-short JSR2
 
-	#0000 .System/eaddr DEO2
+	#0000 EADDR STA2
 
 BRK
 
diff --git a/src/devices/system.c b/src/devices/system.c
index ade0c7d..9deaf41 100644
--- a/src/devices/system.c
+++ b/src/devices/system.c
@@ -14,7 +14,7 @@ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 WITH REGARD TO THIS SOFTWARE.
 */
 
-Uxn hypervisor;
+Uxn supervisor;
 
 static const char *errors[] = {
 	"Working-stack underflow",
@@ -29,27 +29,15 @@ uxn_halt(Uxn *u, Uint8 error, Uint16 addr)
 {
 	Device *d = &u->dev[0];
 	Uint16 vec = d->vector;
-
-	/* hypervisor */
-	d = &hypervisor.dev[0];
-	vec = d->vector;
 	DEVPOKE16(0x4, addr);
 	d->dat[0x6] = error;
-	uxn_eval(&hypervisor, PAGE_PROGRAM);
-
-	/* core */
-	d = &u->dev[0];
-	DEVPOKE16(0x4, addr);
-	d->dat[0x6] = error;
-	vec = d->vector;
-
+	uxn_eval(&supervisor, PAGE_PROGRAM);
 	if(vec) {
 		d->vector = 0; /* need to rearm to run System/vector again */
 		if(error != 2) /* working stack overflow has special treatment */
 			vec += 0x0004;
 		return uxn_eval(u, vec);
 	}
-
 	fprintf(stderr, "Halted: %s#%04x, at 0x%04x\n", errors[error], u->ram[addr], addr);
 	return 0;
 }
diff --git a/src/devices/system.h b/src/devices/system.h
index 6529336..5760ae8 100644
--- a/src/devices/system.h
+++ b/src/devices/system.h
@@ -13,4 +13,4 @@ Uint8 system_dei(Device *d, Uint8 port);
 void system_deo(Device *d, Uint8 port);
 void system_deo_special(Device *d, Uint8 port);
 
-extern Uxn hypervisor;
\ No newline at end of file
+extern Uxn supervisor;
\ No newline at end of file
diff --git a/src/uxn.c b/src/uxn.c
index c3a7f1a..4cc92fd 100644
--- a/src/uxn.c
+++ b/src/uxn.c
@@ -108,15 +108,16 @@ err:
 /* clang-format on */
 
 int
-uxn_boot(Uxn *u, Uint8 *ram, Uint8 *dev, Stack *wst, Stack *rst)
+uxn_boot(Uxn *u, Uint8 *ram, Uint8 *devpage, Stack *wst, Stack *rst)
 {
 	Uint32 i;
 	char *cptr = (char *)u;
 	for(i = 0; i < sizeof(*u); i++)
 		cptr[i] = 0x00;
+	u->ram = ram;
+	u->devpage = devpage;
 	u->wst = wst;
 	u->rst = rst;
-	u->ram = ram;
 	return 1;
 }
 
@@ -124,10 +125,10 @@ Device *
 uxn_port(Uxn *u, Uint8 id, Uint8 (*deifn)(Device *d, Uint8 port), void (*deofn)(Device *d, Uint8 port))
 {
 	Device *d = &u->dev[id];
-	d->addr = id * 0x10;
 	d->u = u;
 	d->mem = u->ram;
 	d->dei = deifn;
 	d->deo = deofn;
+	d->dat = u->devpage + id * 0x10;
 	return d;
 }
diff --git a/src/uxn.h b/src/uxn.h
index 3be5990..797b414 100644
--- a/src/uxn.h
+++ b/src/uxn.h
@@ -16,6 +16,9 @@ typedef signed short Sint16;
 typedef unsigned int Uint32;
 
 #define PAGE_PROGRAM 0x0100
+#define VISOR_DEV 0xfa00
+#define VISOR_WST 0xfb00
+#define VISOR_RST 0xfc00
 #define PAGE_DEV 0xfd00
 #define PAGE_WST 0xfe00
 #define PAGE_RST 0xff00
@@ -28,25 +31,24 @@ typedef unsigned int Uint32;
 /* clang-format on */
 
 typedef struct {
-	Uint8 ptr;
-	Uint8 dat[255];
+	Uint8 ptr, dat[255];
 } Stack;
 
 typedef struct Device {
 	struct Uxn *u;
-	Uint8 addr, dat[16], *mem;
+	Uint8 *dat, *mem;
 	Uint16 vector;
 	Uint8 (*dei)(struct Device *d, Uint8);
 	void (*deo)(struct Device *d, Uint8);
 } Device;
 
 typedef struct Uxn {
+	Uint8 *ram, *devpage;
 	Stack *wst, *rst;
-	Uint8 *ram;
 	Device dev[16];
 } Uxn;
 
-int uxn_boot(Uxn *u, Uint8 *ram, Uint8 *dev, Stack *wst, Stack *rst);
+int uxn_boot(Uxn *u, Uint8 *ram, Uint8 *devpage, Stack *wst, Stack *rst);
 int uxn_eval(Uxn *u, Uint16 pc);
 int uxn_halt(Uxn *u, Uint8 error, Uint16 addr);
 Device *uxn_port(Uxn *u, Uint8 id, Uint8 (*deifn)(Device *, Uint8), void (*deofn)(Device *, Uint8));
diff --git a/src/uxnemu.c b/src/uxnemu.c
index f50dce3..d170343 100644
--- a/src/uxnemu.c
+++ b/src/uxnemu.c
@@ -278,12 +278,12 @@ start(Uxn *u, char *rom)
 	memory = (Uint8 *)calloc(0xffff, sizeof(Uint8));
 	shadow = (Uint8 *)calloc(0xffff, sizeof(Uint8));
 
-	if(!uxn_boot(&hypervisor, shadow, shadow + PAGE_DEV, (Stack *)(shadow + 0xfb00), (Stack *)(shadow + 0xfc00)))
+	if(!uxn_boot(&supervisor, shadow, shadow + VISOR_DEV, (Stack *)(shadow + VISOR_WST), (Stack *)(shadow + VISOR_RST)))
 		return error("Boot", "Failed to start uxn.");
 	if(!uxn_boot(u, memory, shadow + PAGE_DEV, (Stack *)(shadow + PAGE_WST), (Stack *)(shadow + PAGE_RST)))
 		return error("Boot", "Failed to start uxn.");
-	if(!load(&hypervisor, "hypervisor.rom"))
-		error("Hypervisor", "No debugger found.");
+	if(!load(&supervisor, "supervisor.rom"))
+		error("Supervisor", "No debugger found.");
 	if(!load(u, rom))
 		return error("Boot", "Failed to load rom.");
 
@@ -304,10 +304,10 @@ start(Uxn *u, char *rom)
 	/* unused   */ uxn_port(u, 0xe, nil_dei, nil_deo);
 	/* unused   */ uxn_port(u, 0xf, nil_dei, nil_deo);
 
-	/* Hypervisor */
-	uxn_port(&hypervisor, 0x0, system_dei, system_deo);
-	uxn_port(&hypervisor, 0x1, nil_dei, console_deo);
-	uxn_port(&hypervisor, 0x2, screen_dei, screen_deo);
+	/* Supervisor */
+	uxn_port(&supervisor, 0x0, system_dei, system_deo);
+	uxn_port(&supervisor, 0x1, nil_dei, console_deo);
+	uxn_port(&supervisor, 0x2, screen_dei, screen_deo);
 
 	if(!uxn_eval(u, PAGE_PROGRAM))
 		return error("Boot", "Failed to start rom.");
@@ -485,7 +485,7 @@ run(Uxn *u)
 				console_input(u, event.cbutton.button);
 		}
 		if(devsystem->dat[0xe])
-			uxn_eval(&hypervisor, PAGE_PROGRAM);
+			uxn_eval(&supervisor, PAGE_PROGRAM);
 		uxn_eval(u, devscreen->vector);
 		if(uxn_screen.fg.changed || uxn_screen.bg.changed || devsystem->dat[0xe])
 			redraw();