diff --git a/src/devices/system.c b/src/devices/system.c
index e628bb2..5c2a842 100644
--- a/src/devices/system.c
+++ b/src/devices/system.c
@@ -125,7 +125,7 @@ system_deo(Uxn *u, Uint8 *d, Uint8 port)
 /* Errors */
 
 int
-uxn_halt(Uxn *u, Uint8 instr, Uint8 err, Uint16 addr)
+emu_halt(Uxn *u, Uint8 instr, Uint8 err, Uint16 addr)
 {
 	Uint8 *d = &u->dev[0];
 	Uint16 handler = PEEK2(d);
diff --git a/src/uxn.c b/src/uxn.c
index bce2d3d..8f5e58e 100644
--- a/src/uxn.c
+++ b/src/uxn.c
@@ -11,35 +11,32 @@ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 WITH REGARD TO THIS SOFTWARE.
 */
 
-#define T s->dat[s->ptr - 1]
-#define N s->dat[s->ptr - 2]
-#define L s->dat[s->ptr - 3]
-#define H2 PEEK2(s->dat + s->ptr - 3)
-#define T2 PEEK2(s->dat + s->ptr - 2)
-#define N2 PEEK2(s->dat + s->ptr - 4)
-#define L2 PEEK2(s->dat + s->ptr - 6)
-
 /* Registers
-
 [ . ][ . ][ . ][ L ][ N ][ T ] <
 [ . ][ . ][ . ][   H2   ][ T ] <
 [   L2   ][   N2   ][   T2   ] <
-
 */
 
-#define HALT(c) { return uxn_halt(u, ins, (c), pc - 1); }
-#define SET(mul, add) { if(mul > s->ptr) HALT(1) tmp = (mul & k) + add + s->ptr; if(tmp > 254) HALT(2) s->ptr = tmp; }
-#define PUT(o, v) { s->dat[(Uint8)(s->ptr - 1 - (o))] = (v); }
-#define PUT2(o, v) { tmp = (v); s->dat[(Uint8)(s->ptr - o - 2)] = tmp >> 8; s->dat[(Uint8)(s->ptr - o - 1)] = tmp; }
-#define PUSH(v) { if(s->ptr > 254) HALT(2) s->dat[s->ptr++] = (v); }
-#define PUSH2(v) { if(s->ptr > 253) HALT(2) tmp = (v); s->dat[s->ptr] = tmp >> 8; s->dat[s->ptr + 1] = tmp; s->ptr += 2; }
-#define DEO(a, b) { u->dev[(a)] = (b); if((deo_mask[(a) >> 4] >> ((a) & 0xf)) & 0x1) uxn_deo(u, (a)); }
-#define DEI(a, b) { PUT((a), ((dei_mask[(b) >> 4] >> ((b) & 0xf)) & 0x1) ? uxn_dei(u, (b)) : u->dev[(b)]) }
+#define T s->dat[s->ptr - 1]
+#define N s->dat[s->ptr - 2]
+#define L s->dat[s->ptr - 3]
+#define T2 PEEK2(s->dat + s->ptr - 2)
+#define H2 PEEK2(s->dat + s->ptr - 3)
+#define N2 PEEK2(s->dat + s->ptr - 4)
+#define L2 PEEK2(s->dat + s->ptr - 6)
+
+#define HALT(c)    { return emu_halt(u, ins, (c), pc - 1); }
+#define FLIP       { s = ins & 0x40 ? &u->wst : &u->rst; }
+#define SET(x, y)  { if(x > s->ptr) HALT(1) tmp = (x & k) + y + s->ptr; if(tmp > 254) HALT(2) s->ptr = tmp; }
+#define PUT(o, v)  { s->dat[(s->ptr - 1 - (o))] = (v); }
+#define PUT2(o, v) { tmp = (v); POKE2(s->dat + (s->ptr - o - 2), tmp); }
+#define DEO(a, b)  { u->dev[(a)] = (b); if((deo_mask[(a) >> 4] >> ((a) & 0xf)) & 0x1) emu_deo(u, (a)); }
+#define DEI(a, b)  { PUT((a), ((dei_mask[(b) >> 4] >> ((b) & 0xf)) & 0x1) ? emu_dei(u, (b)) : u->dev[(b)]) }
 
 int
 uxn_eval(Uxn *u, Uint16 pc)
 {
-	int t, n, l, k, tmp, opc, ins;
+	int t, n, l, k, tmp, ins, opc;
 	Uint8 *ram = u->ram;
 	Stack *s;
 	if(!pc || u->dev[0x0f]) return 0;
@@ -50,14 +47,14 @@ uxn_eval(Uxn *u, Uint16 pc)
 		opc = !(ins & 0x1f) ? (0 - (ins >> 5)) & 0xff : ins & 0x3f;
 		switch(opc) {
 			/* IMM */
-			case 0x00: /* BRK   */ return 1;
-			case 0xff: /* JCI   */ pc += !!s->dat[--s->ptr] * PEEK2(ram + pc) + 2; break;
-			case 0xfe: /* JMI   */ pc += PEEK2(ram + pc) + 2; break;
-			case 0xfd: /* JSI   */ s = &u->rst; PUSH2(pc + 2) pc += PEEK2(ram + pc) + 2; break;
-			case 0xfc: /* LIT   */ PUSH(ram[pc++]) break;
-			case 0xfb: /* LIT2  */ PUSH2(PEEK2(ram + pc)) pc += 2; break;
-			case 0xfa: /* LITr  */ PUSH(ram[pc++]) break;
-			case 0xf9: /* LIT2r */ PUSH2(PEEK2(ram + pc)) pc += 2; break;
+			case 0x00: /* BRK   */                          return 1;
+			case 0xff: /* JCI   */                          if(!s->dat[--s->ptr]) { pc += 2; break; }
+			case 0xfe: /* JMI   */                          pc += PEEK2(ram + pc) + 2; break;
+			case 0xfd: /* JSI   */                SET(0, 2) PUT2(0, pc + 2) pc += PEEK2(ram + pc) + 2; break;
+			case 0xfc: /* LIT   */                SET(0, 1) PUT(0, ram[pc++]) break;
+			case 0xfb: /* LIT2  */                SET(0, 2) PUT2(0, PEEK2(ram + pc)) pc += 2; break;
+			case 0xfa: /* LITr  */                SET(0, 1) PUT(0, ram[pc++]) break;
+			case 0xf9: /* LIT2r */                SET(0, 2) PUT2(0, PEEK2(ram + pc)) pc += 2; break;
 			/* ALU */
 			case 0x01: /* INC  */ t=T;            SET(1, 0) PUT(0, t + 1) break;
 			case 0x21:            t=T2;           SET(2, 0) PUT2(0, t + 1) break;
@@ -85,10 +82,10 @@ uxn_eval(Uxn *u, Uint16 pc)
 			case 0x2c:            t=T2;           SET(2,-2) pc = t; break;
 			case 0x0d: /* JCN  */ t=T;n=N;        SET(2,-2) if(n) pc += (Sint8)t; break;
 			case 0x2d:            t=T2;n=L;       SET(3,-3) if(n) pc = t; break;
-			case 0x0e: /* JSR  */ t=T;            SET(1,-1) s = &u->rst; PUSH2(pc) pc += (Sint8)t; break;
-			case 0x2e:            t=T2;           SET(2,-2) s = &u->rst; PUSH2(pc) pc = t; break;
-			case 0x0f: /* STH  */ t=T;            SET(1,-1) s = ins & 0x40 ? &u->wst : &u->rst; PUSH(t) break;
-			case 0x2f:            t=T2;           SET(2,-2) s = ins & 0x40 ? &u->wst : &u->rst; PUSH2(t) break;
+			case 0x0e: /* JSR  */ t=T;            SET(1,-1) FLIP SET(0,2) PUT2(0, pc) pc += (Sint8)t; break;
+			case 0x2e:            t=T2;           SET(2,-2) FLIP SET(0,2) PUT2(0, pc) pc = t; break;
+			case 0x0f: /* STH  */ t=T;            SET(1,-1) FLIP SET(0,1) PUT(0, t) break;
+			case 0x2f:            t=T2;           SET(2,-2) FLIP SET(0,2) PUT2(0, t) break;
 			case 0x10: /* LDZ  */ t=T;            SET(1, 0) PUT(0, ram[t]) break;
 			case 0x30:            t=T;            SET(1, 1) PUT2(0, PEEK2(ram + t)) break;
 			case 0x11: /* STZ  */ t=T;n=N;        SET(2,-2) ram[t] = n; break;
diff --git a/src/uxn.h b/src/uxn.h
index 5e4229f..223d22c 100644
--- a/src/uxn.h
+++ b/src/uxn.h
@@ -37,9 +37,9 @@ typedef struct Uxn {
 
 /* required functions */
 
-extern Uint8 uxn_dei(Uxn *u, Uint8 addr);
-extern void uxn_deo(Uxn *u, Uint8 addr);
-extern int uxn_halt(Uxn *u, Uint8 instr, Uint8 err, Uint16 addr);
+extern Uint8 emu_dei(Uxn *u, Uint8 addr);
+extern void emu_deo(Uxn *u, Uint8 addr);
+extern int emu_halt(Uxn *u, Uint8 instr, Uint8 err, Uint16 addr);
 extern Uint16 dei_mask[];
 extern Uint16 deo_mask[];
 
diff --git a/src/uxn11.c b/src/uxn11.c
index bdd965e..f603fd8 100644
--- a/src/uxn11.c
+++ b/src/uxn11.c
@@ -48,7 +48,7 @@ clamp(int val, int min, int max)
 }
 
 Uint8
-uxn_dei(Uxn *u, Uint8 addr)
+emu_dei(Uxn *u, Uint8 addr)
 {
 	switch(addr & 0xf0) {
 	case 0x20: return screen_dei(u, addr);
@@ -58,7 +58,7 @@ uxn_dei(Uxn *u, Uint8 addr)
 }
 
 void
-uxn_deo(Uxn *u, Uint8 addr)
+emu_deo(Uxn *u, Uint8 addr)
 {
 	Uint8 p = addr & 0x0f, d = addr & 0xf0;
 	switch(d) {
diff --git a/src/uxnasm.c b/src/uxnasm.c
index b42ba78..df7a394 100644
--- a/src/uxnasm.c
+++ b/src/uxnasm.c
@@ -35,12 +35,13 @@ typedef struct {
 
 typedef struct {
 	Uint8 data[LENGTH];
+	Uint8 lambda_stack[0x100], lambda_ptr, lambda_count;
+	char scope[0x40], lambda[0x10];
 	unsigned int ptr, length;
-	Uint16 llen, mlen, rlen;
+	Uint16 label_len, macro_len, refs_len;
 	Label labels[0x400];
 	Macro macros[0x100];
 	Reference refs[0x800];
-	char scope[0x40];
 } Program;
 
 Program p;
@@ -87,7 +88,7 @@ static Macro *
 findmacro(char *name)
 {
 	int i;
-	for(i = 0; i < p.mlen; i++)
+	for(i = 0; i < p.macro_len; i++)
 		if(scmp(p.macros[i].name, name, 0x40))
 			return &p.macros[i];
 	return NULL;
@@ -97,7 +98,7 @@ static Label *
 findlabel(char *name)
 {
 	int i;
-	for(i = 0; i < p.llen; i++)
+	for(i = 0; i < p.label_len; i++)
 		if(scmp(p.labels[i].name, name, 0x40))
 			return &p.labels[i];
 	return NULL;
@@ -139,9 +140,9 @@ makemacro(char *name, FILE *f)
 		return error("Macro name is hex number", name);
 	if(findopcode(name) || scmp(name, "BRK", 4) || !slen(name))
 		return error("Macro name is invalid", name);
-	if(p.mlen == 0x100)
+	if(p.macro_len == 0x100)
 		return error("Macros limit exceeded", name);
-	m = &p.macros[p.mlen++];
+	m = &p.macros[p.macro_len++];
 	scpy(name, m->name, 0x40);
 	while(fscanf(f, "%63s", word) == 1) {
 		if(word[0] == '{') continue;
@@ -165,9 +166,9 @@ makelabel(char *name)
 		return error("Label name is hex number", name);
 	if(findopcode(name) || scmp(name, "BRK", 4) || !slen(name))
 		return error("Label name is invalid", name);
-	if(p.llen == 0x400)
+	if(p.label_len == 0x400)
 		return error("Labels limit exceeded", name);
-	l = &p.labels[p.llen++];
+	l = &p.labels[p.label_len++];
 	l->addr = p.ptr;
 	l->refs = 0;
 	scpy(name, l->name, 0x40);
@@ -179,9 +180,9 @@ makereference(char *scope, char *label, char rune, Uint16 addr)
 {
 	char subw[0x40], parent[0x40];
 	Reference *r;
-	if(p.rlen >= 0x800)
+	if(p.refs_len >= 0x800)
 		return error("References limit exceeded", label);
-	r = &p.refs[p.rlen++];
+	r = &p.refs[p.refs_len++];
 	if(label[0] == '&') {
 		if(!sublabel(subw, scope, label + 1))
 			return error("Invalid sublabel", label);
@@ -200,6 +201,15 @@ makereference(char *scope, char *label, char rune, Uint16 addr)
 	return 1;
 }
 
+static char *
+makelambda(int id)
+{
+	scpy("lambda", p.lambda, 0x07);
+	p.lambda[6] = '0' + (id >> 0x4);
+	p.lambda[7] = '0' + (id & 0xf);
+	return p.lambda;
+}
+
 static int
 writebyte(Uint8 b)
 {
@@ -351,6 +361,14 @@ parse(char *w, FILE *f)
 		while((c = w[++i]))
 			if(!writebyte(c)) return 0;
 		break;
+	case '{': /* lambda start */
+		p.lambda_stack[p.lambda_ptr++] = p.lambda_count;
+		makereference(p.scope, makelambda(p.lambda_count++), ' ', p.ptr + 1);
+		return writebyte(0x60) && writeshort(0xffff, 0);
+	case '}': /* lambda end */
+		if(!makelabel(makelambda(p.lambda_stack[--p.lambda_ptr])))
+			return error("Invalid label", w);
+		return writebyte(0x6f);
 	case '[':
 	case ']':
 		if(slen(w) == 1) break; /* else fallthrough */
@@ -384,7 +402,7 @@ resolve(void)
 	Label *l;
 	int i;
 	Uint16 a;
-	for(i = 0; i < p.rlen; i++) {
+	for(i = 0; i < p.refs_len; i++) {
 		Reference *r = &p.refs[i];
 		switch(r->rune) {
 		case '_':
@@ -443,7 +461,7 @@ static void
 review(char *filename)
 {
 	int i;
-	for(i = 0; i < p.llen; i++)
+	for(i = 0; i < p.label_len; i++)
 		if(p.labels[i].name[0] >= 'A' && p.labels[i].name[0] <= 'Z')
 			continue; /* Ignore capitalized labels(devices) */
 		else if(!p.labels[i].refs)
@@ -453,8 +471,8 @@ review(char *filename)
 		filename,
 		p.length - TRIM,
 		(p.length - TRIM) / 652.80,
-		p.llen,
-		p.mlen);
+		p.label_len,
+		p.macro_len);
 }
 
 static void
@@ -467,7 +485,7 @@ writesym(char *filename)
 		return;
 	fp = fopen(scat(scpy(filename, symdst, slen(filename) + 1), ".sym"), "w");
 	if(fp != NULL) {
-		for(i = 0; i < p.llen; i++) {
+		for(i = 0; i < p.label_len; i++) {
 			Uint8 hb = p.labels[i].addr >> 8, lb = p.labels[i].addr & 0xff;
 			fwrite(&hb, 1, 1, fp);
 			fwrite(&lb, 1, 1, fp);
diff --git a/src/uxncli.c b/src/uxncli.c
index fd0ce81..bbeb519 100644
--- a/src/uxncli.c
+++ b/src/uxncli.c
@@ -21,7 +21,7 @@ Uint16 deo_mask[] = {0xc028, 0x0300, 0xc028, 0x8000, 0x8000, 0x8000, 0x8000, 0x0
 Uint16 dei_mask[] = {0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x07ff, 0x0000, 0x0000, 0x0000};
 
 Uint8
-uxn_dei(Uxn *u, Uint8 addr)
+emu_dei(Uxn *u, Uint8 addr)
 {
 	switch(addr & 0xf0) {
 	case 0xc0: return datetime_dei(u, addr);
@@ -30,7 +30,7 @@ uxn_dei(Uxn *u, Uint8 addr)
 }
 
 void
-uxn_deo(Uxn *u, Uint8 addr)
+emu_deo(Uxn *u, Uint8 addr)
 {
 	Uint8 p = addr & 0x0f, d = addr & 0xf0;
 	switch(d) {