diff --git a/html/css/app.css b/html/css/app.css
index 5e0927c..ce314f4 100644
--- a/html/css/app.css
+++ b/html/css/app.css
@@ -438,41 +438,52 @@ body {
   body > * {
     margin-left: auto;
     margin-right: auto; }
-  body h1 {
-    text-align: center;
-    font-size: 2.02729em;
-    margin-top: 0;
-    margin-bottom: 1rem; }
-    @media screen and (max-width: 544px) {
-      body h1 {
-        font-size: 1.42383em;
-        margin-bottom: 0.61805rem; } }
-    @media screen and (min-width: 545px) and (max-width: 1000px) {
-      body h1 {
-        font-size: 1.80203em; } }
-  body h2 {
-    font-size: 1.26563em;
-    margin-bottom: 0.61805rem; }
-    body h2:first-child {
-      margin-top: 0; }
-  body td, body th {
-    padding: 0.38198rem;
-    white-space: nowrap; }
-    @media screen and (max-width: 544px) {
-      body td, body th {
-        padding: 0.23608rem; } }
-  body tbody th {
-    text-align: right;
-    width: 130px;
-    color: white; }
-    @media screen and (max-width: 544px) {
-      body tbody th {
-        width: auto; } }
-  body tbody td input[type="text"], body tbody td input[type="number"] {
-    width: 10em; }
-    @media screen and (max-width: 544px) {
-      body tbody td input[type="text"], body tbody td input[type="number"] {
-        width: 8em; } }
+
+h1, h2 {
+  -webkit-user-select: none;
+  -moz-user-select: none;
+  -ms-user-select: none;
+  user-select: none; }
+
+h1 {
+  text-align: center;
+  font-size: 2.02729em;
+  margin-top: 0;
+  margin-bottom: 1rem; }
+  @media screen and (max-width: 544px) {
+    h1 {
+      font-size: 1.42383em;
+      margin-bottom: 0.61805rem; } }
+  @media screen and (min-width: 545px) and (max-width: 1000px) {
+    h1 {
+      font-size: 1.80203em; } }
+
+h2 {
+  font-size: 1.26563em;
+  margin-bottom: 0.61805rem; }
+  h2:first-child {
+    margin-top: 0; }
+
+td, th {
+  padding: 0.38198rem;
+  white-space: nowrap; }
+  @media screen and (max-width: 544px) {
+    td, th {
+      padding: 0.23608rem; } }
+
+tbody th {
+  text-align: right;
+  width: 130px;
+  color: white; }
+  @media screen and (max-width: 544px) {
+    tbody th {
+      width: auto; } }
+
+tbody td input[type="text"], tbody td input[type="number"] {
+  width: 10em; }
+  @media screen and (max-width: 544px) {
+    tbody td input[type="text"], tbody td input[type="number"] {
+      width: 8em; } }
 
 #loader {
   position: absolute;
diff --git a/html/js/app.js b/html/js/app.js
index aae60c2..bdc2c45 100644
--- a/html/js/app.js
+++ b/html/js/app.js
@@ -894,6 +894,7 @@ $._loader = function(vis) {
 		var W, H;
 		var cursor = {a: false, x: 0, y: 0, suppress: false, hidden: false};
 		var screen = [];
+		var blinkIval;
 
 		/** Colors table */
 		var CLR = [// dark gray #2E3436
@@ -1071,7 +1072,8 @@ $._loader = function(vis) {
 			}
 
 			/* Cursor blinking */
-			setInterval(function() {
+			clearInterval(blinkIval);
+			blinkIval = setInterval(function() {
 				cursor.a = !cursor.a;
 				if (cursor.hidden) {
 					cursor.a = false;
diff --git a/html_orig/css/app.css b/html_orig/css/app.css
index 5e0927c..ce314f4 100644
--- a/html_orig/css/app.css
+++ b/html_orig/css/app.css
@@ -438,41 +438,52 @@ body {
   body > * {
     margin-left: auto;
     margin-right: auto; }
-  body h1 {
-    text-align: center;
-    font-size: 2.02729em;
-    margin-top: 0;
-    margin-bottom: 1rem; }
-    @media screen and (max-width: 544px) {
-      body h1 {
-        font-size: 1.42383em;
-        margin-bottom: 0.61805rem; } }
-    @media screen and (min-width: 545px) and (max-width: 1000px) {
-      body h1 {
-        font-size: 1.80203em; } }
-  body h2 {
-    font-size: 1.26563em;
-    margin-bottom: 0.61805rem; }
-    body h2:first-child {
-      margin-top: 0; }
-  body td, body th {
-    padding: 0.38198rem;
-    white-space: nowrap; }
-    @media screen and (max-width: 544px) {
-      body td, body th {
-        padding: 0.23608rem; } }
-  body tbody th {
-    text-align: right;
-    width: 130px;
-    color: white; }
-    @media screen and (max-width: 544px) {
-      body tbody th {
-        width: auto; } }
-  body tbody td input[type="text"], body tbody td input[type="number"] {
-    width: 10em; }
-    @media screen and (max-width: 544px) {
-      body tbody td input[type="text"], body tbody td input[type="number"] {
-        width: 8em; } }
+
+h1, h2 {
+  -webkit-user-select: none;
+  -moz-user-select: none;
+  -ms-user-select: none;
+  user-select: none; }
+
+h1 {
+  text-align: center;
+  font-size: 2.02729em;
+  margin-top: 0;
+  margin-bottom: 1rem; }
+  @media screen and (max-width: 544px) {
+    h1 {
+      font-size: 1.42383em;
+      margin-bottom: 0.61805rem; } }
+  @media screen and (min-width: 545px) and (max-width: 1000px) {
+    h1 {
+      font-size: 1.80203em; } }
+
+h2 {
+  font-size: 1.26563em;
+  margin-bottom: 0.61805rem; }
+  h2:first-child {
+    margin-top: 0; }
+
+td, th {
+  padding: 0.38198rem;
+  white-space: nowrap; }
+  @media screen and (max-width: 544px) {
+    td, th {
+      padding: 0.23608rem; } }
+
+tbody th {
+  text-align: right;
+  width: 130px;
+  color: white; }
+  @media screen and (max-width: 544px) {
+    tbody th {
+      width: auto; } }
+
+tbody td input[type="text"], tbody td input[type="number"] {
+  width: 10em; }
+  @media screen and (max-width: 544px) {
+    tbody td input[type="text"], tbody td input[type="number"] {
+      width: 8em; } }
 
 #loader {
   position: absolute;
diff --git a/html_orig/jssrc/term.js b/html_orig/jssrc/term.js
index 9d73eb8..916c2c0 100644
--- a/html_orig/jssrc/term.js
+++ b/html_orig/jssrc/term.js
@@ -6,6 +6,7 @@
 		var W, H;
 		var cursor = {a: false, x: 0, y: 0, suppress: false, hidden: false};
 		var screen = [];
+		var blinkIval;
 
 		/** Colors table */
 		var CLR = [// dark gray #2E3436
@@ -183,7 +184,8 @@
 			}
 
 			/* Cursor blinking */
-			setInterval(function() {
+			clearInterval(blinkIval);
+			blinkIval = setInterval(function() {
 				cursor.a = !cursor.a;
 				if (cursor.hidden) {
 					cursor.a = false;
diff --git a/html_orig/sass/_layout.scss b/html_orig/sass/_layout.scss
index 9326f07..56c06c3 100644
--- a/html_orig/sass/_layout.scss
+++ b/html_orig/sass/_layout.scss
@@ -78,55 +78,59 @@ body {
 		margin-left: auto;
 		margin-right: auto;
 	}
+}
 
-	h1 {
-		text-align: center;
-		font-size: fsize(6);
-		margin-top: 0;
-		margin-bottom: dist(0);
+h1,h2 {
+	@include noselect();
+}
 
-		@include media($phone) {
-			font-size: fsize(3);
-			margin-bottom: dist(-1);
-		}
+h1 {
+	text-align: center;
+	font-size: fsize(6);
+	margin-top: 0;
+	margin-bottom: dist(0);
 
-		@include media($tablet) {
-			font-size: fsize(5);
-		}
+	@include media($phone) {
+		font-size: fsize(3);
+		margin-bottom: dist(-1);
 	}
 
-	h2 {
-		font-size: fsize(2);
-		margin-bottom: dist(-1);
-		&:first-child{margin-top:0}
+	@include media($tablet) {
+		font-size: fsize(5);
 	}
+}
+
+h2 {
+	font-size: fsize(2);
+	margin-bottom: dist(-1);
+	&:first-child{margin-top:0}
+}
 
-	td, th {
-		padding: dist(-2);
-		white-space: nowrap;
+td, th {
+	padding: dist(-2);
+	white-space: nowrap;
 
-		@include media($phone) {
-			padding: dist(-3);
-		}
+	@include media($phone) {
+		padding: dist(-3);
 	}
+}
 
-	tbody th {
-		text-align: right;
-		width: $form-label-w;
-		color: $c-form-label-fg;
+tbody th {
+	text-align: right;
+	width: $form-label-w;
+	color: $c-form-label-fg;
 
-		@include media($phone) {
-			width: auto;
-		}
+	@include media($phone) {
+		width: auto;
 	}
+}
 
-	tbody td {
-		input[type="text"], input[type="number"] {
-			width: 10em;
+tbody td {
+	input[type="text"], input[type="number"] {
+		width: 10em;
 
-			@include media($phone) {
-				width: 8em;
-			}
+		@include media($phone) {
+			width: 8em;
 		}
 	}
 }
diff --git a/user/ansi_parser.c b/user/ansi_parser.c
index 9edd515..9791a7c 100644
--- a/user/ansi_parser.c
+++ b/user/ansi_parser.c
@@ -182,28 +182,49 @@ handle_plainchar(char c)
 	screen_putchar(c);
 }
 
+void ICACHE_FLASH_ATTR
+handle_OSC_FactoryReset(void)
+{
+	info("OSC: Factory reset");
+
+	warn("NOT IMPLEMENTED");
+	// TODO
+}
+
+void ICACHE_FLASH_ATTR
+handle_OSC_SetScreenSize(int rows, int cols)
+{
+	info("OSC: Set screen size to %d x %d", rows, cols);
+
+	screen_resize(rows, cols);
+}
+
+
 /* Ragel constants block */
 
-/* #line 188 "user/ansi_parser.c" */
+/* #line 206 "user/ansi_parser.c" */
 static const char _ansi_actions[] = {
 	0, 1, 0, 1, 1, 1, 2, 1, 
 	3, 1, 4, 1, 5, 1, 6, 1, 
-	7, 1, 8, 1, 9
+	7, 1, 8, 1, 9, 1, 10
 };
 
 static const char _ansi_eof_actions[] = {
-	0, 15, 15, 13, 13, 0, 0
+	0, 13, 13, 13, 13, 13, 13, 13, 
+	13, 13, 13, 13, 13, 13, 0, 0, 
+	0
 };
 
 static const int ansi_start = 1;
-static const int ansi_first_final = 5;
+static const int ansi_first_final = 14;
 static const int ansi_error = 0;
 
 static const int ansi_en_CSI_body = 3;
+static const int ansi_en_OSC_body = 5;
 static const int ansi_en_main = 1;
 
 
-/* #line 187 "user/ansi_parser.rl" */
+/* #line 205 "user/ansi_parser.rl" */
 
 
 /**
@@ -240,17 +261,17 @@ ansi_parser(const char *newdata, size_t len)
 	// Init Ragel on the first run
 	if (cs == -1) {
 		
-/* #line 244 "user/ansi_parser.c" */
+/* #line 265 "user/ansi_parser.c" */
 	{
 	cs = ansi_start;
 	}
 
-/* #line 223 "user/ansi_parser.rl" */
+/* #line 241 "user/ansi_parser.rl" */
 	}
 
 	// The parser
 	
-/* #line 254 "user/ansi_parser.c" */
+/* #line 275 "user/ansi_parser.c" */
 	{
 	const char *_acts;
 	unsigned int _nacts;
@@ -274,79 +295,137 @@ case 2:
 	goto tr2;
 case 0:
 	goto _out;
-case 5:
+case 14:
 	if ( (*p) == 27 )
 		goto tr1;
 	goto tr0;
 case 3:
 	if ( (*p) == 59 )
-		goto tr9;
+		goto tr8;
 	if ( (*p) < 60 ) {
 		if ( (*p) > 47 ) {
 			if ( 48 <= (*p) && (*p) <= 57 )
-				goto tr8;
+				goto tr7;
 		} else if ( (*p) >= 32 )
-			goto tr7;
+			goto tr6;
 	} else if ( (*p) > 64 ) {
 		if ( (*p) > 90 ) {
 			if ( 97 <= (*p) && (*p) <= 122 )
-				goto tr10;
+				goto tr9;
 		} else if ( (*p) >= 65 )
-			goto tr10;
+			goto tr9;
 	} else
-		goto tr7;
-	goto tr6;
+		goto tr6;
+	goto tr2;
 case 4:
 	if ( (*p) == 59 )
-		goto tr9;
+		goto tr8;
 	if ( (*p) < 65 ) {
 		if ( 48 <= (*p) && (*p) <= 57 )
-			goto tr8;
+			goto tr7;
 	} else if ( (*p) > 90 ) {
 		if ( 97 <= (*p) && (*p) <= 122 )
-			goto tr10;
+			goto tr9;
 	} else
-		goto tr10;
-	goto tr6;
+		goto tr9;
+	goto tr2;
+case 15:
+	goto tr2;
+case 5:
+	switch( (*p) ) {
+		case 70: goto tr10;
+		case 87: goto tr11;
+	}
+	goto tr2;
 case 6:
-	goto tr6;
+	if ( (*p) == 82 )
+		goto tr12;
+	goto tr2;
+case 7:
+	switch( (*p) ) {
+		case 7: goto tr13;
+		case 27: goto tr14;
+	}
+	goto tr2;
+case 16:
+	goto tr2;
+case 8:
+	if ( (*p) == 92 )
+		goto tr13;
+	goto tr2;
+case 9:
+	if ( 48 <= (*p) && (*p) <= 57 )
+		goto tr15;
+	goto tr2;
+case 10:
+	if ( (*p) == 59 )
+		goto tr16;
+	if ( 48 <= (*p) && (*p) <= 57 )
+		goto tr15;
+	goto tr2;
+case 11:
+	if ( 48 <= (*p) && (*p) <= 57 )
+		goto tr17;
+	goto tr2;
+case 12:
+	switch( (*p) ) {
+		case 7: goto tr18;
+		case 27: goto tr19;
+	}
+	if ( 48 <= (*p) && (*p) <= 57 )
+		goto tr17;
+	goto tr2;
+case 13:
+	if ( (*p) == 92 )
+		goto tr18;
+	goto tr2;
 	}
 
 	tr2: cs = 0; goto f0;
-	tr6: cs = 0; goto f5;
 	tr0: cs = 1; goto f1;
 	tr1: cs = 2; goto _again;
+	tr6: cs = 4; goto f5;
 	tr7: cs = 4; goto f6;
 	tr8: cs = 4; goto f7;
-	tr9: cs = 4; goto f8;
-	tr3: cs = 5; goto f2;
-	tr4: cs = 5; goto f3;
-	tr5: cs = 5; goto f4;
-	tr10: cs = 6; goto f9;
+	tr10: cs = 6; goto _again;
+	tr12: cs = 7; goto _again;
+	tr14: cs = 8; goto _again;
+	tr11: cs = 9; goto _again;
+	tr15: cs = 10; goto f6;
+	tr16: cs = 11; goto f7;
+	tr17: cs = 12; goto f6;
+	tr19: cs = 13; goto _again;
+	tr3: cs = 14; goto f2;
+	tr4: cs = 14; goto f3;
+	tr5: cs = 14; goto f4;
+	tr9: cs = 15; goto f8;
+	tr13: cs = 16; goto f9;
+	tr18: cs = 16; goto f10;
 
 	f1: _acts = _ansi_actions + 1; goto execFuncs;
 	f2: _acts = _ansi_actions + 3; goto execFuncs;
-	f6: _acts = _ansi_actions + 5; goto execFuncs;
-	f7: _acts = _ansi_actions + 7; goto execFuncs;
-	f8: _acts = _ansi_actions + 9; goto execFuncs;
-	f9: _acts = _ansi_actions + 11; goto execFuncs;
-	f5: _acts = _ansi_actions + 13; goto execFuncs;
-	f0: _acts = _ansi_actions + 15; goto execFuncs;
-	f3: _acts = _ansi_actions + 17; goto execFuncs;
-	f4: _acts = _ansi_actions + 19; goto execFuncs;
+	f5: _acts = _ansi_actions + 5; goto execFuncs;
+	f6: _acts = _ansi_actions + 7; goto execFuncs;
+	f7: _acts = _ansi_actions + 9; goto execFuncs;
+	f8: _acts = _ansi_actions + 11; goto execFuncs;
+	f0: _acts = _ansi_actions + 13; goto execFuncs;
+	f3: _acts = _ansi_actions + 15; goto execFuncs;
+	f9: _acts = _ansi_actions + 17; goto execFuncs;
+	f10: _acts = _ansi_actions + 19; goto execFuncs;
+	f4: _acts = _ansi_actions + 21; goto execFuncs;
 
 execFuncs:
 	_nacts = *_acts++;
 	while ( _nacts-- > 0 ) {
 		switch ( *_acts++ ) {
 	case 0:
-/* #line 233 "user/ansi_parser.rl" */
+/* #line 251 "user/ansi_parser.rl" */
 	{
 			handle_plainchar((*p));
 		}
 	break;
 	case 1:
-/* #line 240 "user/ansi_parser.rl" */
+/* #line 258 "user/ansi_parser.rl" */
 	{
 			/* Reset the CSI builder */
 			csi_leading = csi_char = 0;
@@ -361,13 +440,13 @@ execFuncs:
 		}
 	break;
 	case 2:
-/* #line 253 "user/ansi_parser.rl" */
+/* #line 271 "user/ansi_parser.rl" */
 	{
 			csi_leading = (*p);
 		}
 	break;
 	case 3:
-/* #line 257 "user/ansi_parser.rl" */
+/* #line 275 "user/ansi_parser.rl" */
 	{
 			/* x10 + digit */
 			if (csi_ni < CSI_N_MAX) {
@@ -376,13 +455,13 @@ execFuncs:
 		}
 	break;
 	case 4:
-/* #line 264 "user/ansi_parser.rl" */
+/* #line 282 "user/ansi_parser.rl" */
 	{
 			csi_ni++;
 		}
 	break;
 	case 5:
-/* #line 268 "user/ansi_parser.rl" */
+/* #line 286 "user/ansi_parser.rl" */
 	{
 			csi_char = (*p);
 
@@ -392,33 +471,49 @@ execFuncs:
 		}
 	break;
 	case 6:
-/* #line 276 "user/ansi_parser.rl" */
+/* #line 294 "user/ansi_parser.rl" */
 	{
+			warn("Invalid escape sequence discarded.");
 			{cs = 1; goto _again;}
 		}
 	break;
 	case 7:
-/* #line 280 "user/ansi_parser.rl" */
+/* #line 311 "user/ansi_parser.rl" */
 	{
-			{cs = 1; goto _again;}
+			csi_ni = 0;
+
+			// we reuse the CSI numeric buffer
+			for(int i = 0; i < CSI_N_MAX; i++) {
+				csi_n[i] = 0;
+			}
+
+			{cs = 5; goto _again;}
 		}
 	break;
 	case 8:
-/* #line 292 "user/ansi_parser.rl" */
+/* #line 322 "user/ansi_parser.rl" */
 	{
-			// TODO implement OS control code parsing
+			handle_OSC_FactoryReset();
 			{cs = 1; goto _again;}
 		}
 	break;
 	case 9:
-/* #line 297 "user/ansi_parser.rl" */
+/* #line 327 "user/ansi_parser.rl" */
+	{
+			handle_OSC_SetScreenSize(csi_n[0], csi_n[1]);
+
+			{cs = 1; goto _again;}
+		}
+	break;
+	case 10:
+/* #line 338 "user/ansi_parser.rl" */
 	{
 			// Reset screen
 			handle_RESET_cmd();
 			{cs = 1; goto _again;}
 		}
 	break;
-/* #line 422 "user/ansi_parser.c" */
+/* #line 517 "user/ansi_parser.c" */
 		}
 	}
 	goto _again;
@@ -436,18 +531,13 @@ _again:
 	while ( __nacts-- > 0 ) {
 		switch ( *__acts++ ) {
 	case 6:
-/* #line 276 "user/ansi_parser.rl" */
-	{
-			{cs = 1; goto _again;}
-		}
-	break;
-	case 7:
-/* #line 280 "user/ansi_parser.rl" */
+/* #line 294 "user/ansi_parser.rl" */
 	{
+			warn("Invalid escape sequence discarded.");
 			{cs = 1; goto _again;}
 		}
 	break;
-/* #line 451 "user/ansi_parser.c" */
+/* #line 541 "user/ansi_parser.c" */
 		}
 	}
 	}
@@ -455,6 +545,6 @@ _again:
 	_out: {}
 	}
 
-/* #line 315 "user/ansi_parser.rl" */
+/* #line 356 "user/ansi_parser.rl" */
 
 }
diff --git a/user/ansi_parser.rl b/user/ansi_parser.rl
index 46c504d..bab6b71 100644
--- a/user/ansi_parser.rl
+++ b/user/ansi_parser.rl
@@ -180,6 +180,24 @@ handle_plainchar(char c)
 	screen_putchar(c);
 }
 
+void ICACHE_FLASH_ATTR
+handle_OSC_FactoryReset(void)
+{
+	info("OSC: Factory reset");
+
+	warn("NOT IMPLEMENTED");
+	// TODO
+}
+
+void ICACHE_FLASH_ATTR
+handle_OSC_SetScreenSize(int rows, int cols)
+{
+	info("OSC: Set screen size to %d x %d", rows, cols);
+
+	screen_resize(rows, cols);
+}
+
+
 /* Ragel constants block */
 %%{
 	machine ansi;
@@ -273,26 +291,49 @@ ansi_parser(const char *newdata, size_t len)
 			fgoto main;
 		}
 
-		action CSI_fail {
+		action errBadSeq {
+			warn("Invalid escape sequence discarded.");
 			fgoto main;
 		}
 
-		action main_fail {
+		action back2main {
 			fgoto main;
 		}
 
 		CSI_body := ((32..47|60..64) @CSI_leading)?
 			((digit @CSI_digit)* ';' @CSI_semi)*
-			(digit @CSI_digit)* alpha @CSI_end $!CSI_fail;
+			(digit @CSI_digit)* alpha @CSI_end $!errBadSeq;
 
 
 		# --- OSC commands (Operating System Commands) ---
 		# Module parametrisation
 
 		action OSC_start {
-			// TODO implement OS control code parsing
+			csi_ni = 0;
+
+			// we reuse the CSI numeric buffer
+			for(int i = 0; i < CSI_N_MAX; i++) {
+				csi_n[i] = 0;
+			}
+
+			fgoto OSC_body;
+		}
+
+		action OSC_fr {
+			handle_OSC_FactoryReset();
+			fgoto main;
+		}
+
+		action OSC_resize {
+			handle_OSC_SetScreenSize(csi_n[0], csi_n[1]);
+
 			fgoto main;
 		}
+		
+		OSC_body := (
+			("FR" ('\a' | ESC '\\') @OSC_fr) |
+			('W' (digit @CSI_digit)+ ';' @CSI_semi (digit @CSI_digit)+ ('\a' | ESC '\\') @OSC_resize)
+		) $!errBadSeq;
 
 		action RESET_cmd {
 			// Reset screen
@@ -309,7 +350,7 @@ ansi_parser(const char *newdata, size_t len)
 					']' @OSC_start |
 					'c' @RESET_cmd
 				)
-			)+ $!main_fail;
+			)+ $!errBadSeq;
 
 		write exec;
 	}%%
diff --git a/user/screen.c b/user/screen.c
index 5320d39..4f03887 100644
--- a/user/screen.c
+++ b/user/screen.c
@@ -189,20 +189,28 @@ screen_clear_line(ClearMode mode)
 /**
  * Change the screen size
  *
- * @param w - new width
- * @param h - new height
+ * @param cols - new width
+ * @param rows - new height
  */
 void ICACHE_FLASH_ATTR
-screen_resize(Coordinate w, Coordinate h)
+screen_resize(Coordinate rows, Coordinate cols)
 {
 	NOTIFY_LOCK();
 	// sanitize
-	if (w < 1) w = 1;
-	if (h < 1) h = 1;
+	if (cols < 1 || rows < 1) {
+		error("Screen size must be positive");
+		goto done;
+	}
+
+	if (cols * rows > MAX_SCREEN_SIZE) {
+		error("Max screen size exceeded");
+		goto done;
+	}
 
-	W = w;
-	H = h;
+	W = cols;
+	H = rows;
 	screen_reset();
+done:
 	NOTIFY_DONE();
 }
 
@@ -579,11 +587,11 @@ screenSerializeToBuffer(char *buffer, size_t buf_len, void **data)
 		ss->lastFg = 0;
 		ss->lastChar = '\0';
 
-		bufprint("{\"w\":%d,\"h\":%d,\"x\":%d,\"y\":%d,\"cv\":%d,\"screen\":\"", W, H, cursor.x, cursor.y, cursor.visible);
+		bufprint("{\n \"w\": %d, \"h\": %d,\n \"x\": %d, \"y\": %d,\n \"cv\": %d,\n \"screen\": \"", W, H, cursor.x, cursor.y, cursor.visible);
 	}
 
 	int i = ss->index;
-	while(i < W*H && remain > 6) {
+	while(i < W*H && remain > 12) {
 		cell = cell0 = &screen[i];
 
 		// Count how many times same as previous
@@ -598,11 +606,25 @@ screenSerializeToBuffer(char *buffer, size_t buf_len, void **data)
 		}
 
 		if (repCnt == 0) {
+			// All this crap is needed because it's JSON and also
+			// embedded in HTML (hence the angle brackets)
+
 			if (cell0->fg == ss->lastFg && cell0->bg == ss->lastBg) {
 				// same colors as previous
-				bufprint(",%c", cell0->c);
+				bufprint(",");
 			} else {
-				bufprint("%X%X%c", cell0->fg, cell0->bg, cell0->c);
+				bufprint("%X%X", cell0->fg, cell0->bg);
+			}
+
+			char c = cell0->c;
+			if (c == '"' || c == '\\') {
+				bufprint("\\%c", c);
+			}
+			else if (c == '<' || c == '>' || c == '\'' || c == '/' || c == '&') {
+				bufprint("\\u00%02X", (int)c);
+			}
+			else {
+				bufprint("%c", c);
 			}
 
 			ss->lastFg = cell0->fg;
@@ -633,7 +655,7 @@ screenSerializeToBuffer(char *buffer, size_t buf_len, void **data)
 	}
 
 	if (remain >= 3) {
-		bufprint("\"}");
+		bufprint("\"\n}");
 		return HTTPD_CGI_DONE;
 	} else {
 		return HTTPD_CGI_MORE;
diff --git a/user/screen.h b/user/screen.h
index 677b6c4..d8a02ad 100644
--- a/user/screen.h
+++ b/user/screen.h
@@ -62,7 +62,7 @@ screenSerializeToBuffer(char *buffer, size_t buf_len, void **data);
 void screen_init(void);
 
 /** Change the screen size */
-void screen_resize(Coordinate w, Coordinate h);
+void screen_resize(Coordinate rows, Coordinate cols);
 
 // --- Clearing ---
 
diff --git a/user/user_main.c b/user/user_main.c
index 305c195..0f33295 100644
--- a/user/user_main.c
+++ b/user/user_main.c
@@ -50,17 +50,20 @@ static ETSTimer prHeapTimer;
 /** Periodically show heap usage */
 static void ICACHE_FLASH_ATTR prHeapTimerCb(void *arg)
 {
-	static uint32_t cnt = 0;
 	static uint32_t last = 0;
 
-	if (cnt == 5) {
-		uint32_t heap = system_get_free_heap_size();
-		dbg("Free heap: %d bytes (~ %d)", heap, (heap-last));
-		cnt = 0;
-		last = heap;
+	uint32_t heap = system_get_free_heap_size();
+	int32_t diff = (heap-last);
+	const char *cc = "+";
+	if (diff<0) cc = "";
+
+	if (diff == 0) {
+		dbg("Free heap: %d bytes", heap);
+	} else {
+		dbg("Free heap: %d bytes (%s%d)", heap, cc, diff);
 	}
 
-	cnt++;
+	last = heap;
 }
 
 //Main routine. Initialize stdout, the I/O, filesystem and the webserver and we're done.
@@ -97,7 +100,7 @@ void ICACHE_FLASH_ATTR user_init(void)
 	// Heap use timer & blink
 	os_timer_disarm(&prHeapTimer);
 	os_timer_setfn(&prHeapTimer, prHeapTimerCb, NULL);
-	os_timer_arm(&prHeapTimer, 1000, 1);
+	os_timer_arm(&prHeapTimer, 5000, 1);
 
 	// The terminal screen
 	screen_init();