diff --git a/CMakeLists.txt b/CMakeLists.txt
index 24555ad..edf13be 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -145,6 +145,7 @@ add_definitions(
         -DFLAG_GZIP=2
         -DADMIN_PASSWORD="asdf"
         -DGIT_HASH="blabla"
+        -DDEBUG_ANSI=1
         -DESPFS_HEATSHRINK)
 
 add_executable(esp_vt100_firmware ${SOURCE_FILES})
diff --git a/Makefile b/Makefile
index 0b351b6..3ada8cd 100644
--- a/Makefile
+++ b/Makefile
@@ -65,8 +65,15 @@ LIBS += esphttpd
 # compiler flags using during compilation of source files
 CFLAGS		= -Os -ggdb -std=gnu99 -Werror -Wpointer-arith -Wundef -Wall -Wl,-EL -fno-inline-functions \
 		-nostdlib -mlongcalls -mtext-section-literals  -D__ets__ -DICACHE_FLASH \
-		-Wno-address -Wno-unused -DHTTPD_MAX_BACKLOG_SIZE=8192 -DADMIN_PASSWORD=$(ADMIN_PASSWORD) \
-		-DGIT_HASH='"$(shell git rev-parse --short HEAD)"'
+		-Wno-address -Wno-unused
+
+CFLAGS += -DHTTPD_MAX_BACKLOG_SIZE=8192
+CFLAGS += -DGIT_HASH='"$(shell git rev-parse --short HEAD)"'
+CFLAGS += -DADMIN_PASSWORD=$(ADMIN_PASSWORD)
+
+# Debug logging
+CFLAGS += -DDEBUG_ANSI=1
+CFLAGS += -DDEBUG_INPUT=1
 
 # linker flags used to generate the main object file
 LDFLAGS		= -nostdlib -Wl,--no-check-sections -u call_user_start -Wl,-static
diff --git a/user/ansi_parser.c b/user/ansi_parser.c
index ed593ca..8bd1f73 100644
--- a/user/ansi_parser.c
+++ b/user/ansi_parser.c
@@ -11,26 +11,27 @@ 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, 1, 10, 1, 
-	11, 1, 12, 1, 13, 1, 14, 2, 
-	2, 5, 2, 10, 11, 2, 10, 12
-	
+	11, 1, 12, 1, 13, 1, 14, 1, 
+	15, 1, 16, 1, 17, 2, 2, 5, 
+	2, 10, 11, 2, 10, 12
 };
 
 static const char _ansi_eof_actions[] = {
 	0, 13, 13, 13, 13, 13, 13, 13, 
 	13, 13, 13, 13, 13, 13, 13, 13, 
 	13, 13, 13, 13, 13, 13, 13, 13, 
-	13, 13, 13, 13, 0, 0, 0, 0, 
-	0, 0, 0, 0
+	13, 13, 13, 13, 13, 13, 0, 0, 
+	0, 0, 0, 0, 0, 0, 0
 };
 
 static const int ansi_start = 1;
-static const int ansi_first_final = 28;
+static const int ansi_first_final = 30;
 static const int ansi_error = 0;
 
-static const int ansi_en_CSI_body = 4;
-static const int ansi_en_OSC_body = 6;
-static const int ansi_en_TITLE_body = 26;
+static const int ansi_en_CSI_body = 5;
+static const int ansi_en_OSC_body = 7;
+static const int ansi_en_TITLE_body = 27;
+static const int ansi_en_charsetcmd_body = 29;
 static const int ansi_en_main = 1;
 
 
@@ -45,10 +46,39 @@ static void ICACHE_FLASH_ATTR
 resetParserCb(void *arg) {
 	if (cs != ansi_start) {
 		cs = ansi_start;
-		warn("Parser timeout, state reset");
+		apars_reset_utf8buffer();
+		ansi_warn("Parser timeout, state reset");
 	}
 }
 
+#define HISTORY_LEN 16
+
+#if DEBUG_ANSI
+static char history[HISTORY_LEN + 1];
+#endif
+
+void ICACHE_FLASH_ATTR
+apars_handle_badseq(void)
+{
+#if DEBUG_ANSI
+	char buf1[HISTORY_LEN*3+2];
+	char buf2[HISTORY_LEN*3+2];
+	char *b1 = buf1;
+	char *b2 = buf2;
+	char c;
+
+	for(int i=0;i<HISTORY_LEN;i++) {
+		c = history[i];
+		b1 += sprintf(b1, "%2X ", c);
+		if (c < 32 || c > 127) c = '.';
+		b2 += sprintf(b2, "%c  ", c);
+	}
+
+	ansi_dbg("Context: %s", buf2);
+	ansi_dbg("         %s", buf1);
+#endif
+}
+
 /**
  * \brief Linear ANSI chars stream parser
  *
@@ -68,6 +98,7 @@ ansi_parser(const char *newdata, size_t len)
 	// The CSI code is built here
 	static char csi_leading;      //!< Leading char, 0 if none
 	static int  csi_ni;           //!< Number of the active digit
+	static int  csi_cnt;          //!< Digit count
 	static int  csi_n[CSI_N_MAX]; //!< Param digits
 	static char csi_char;         //!< CSI action char (end)
 	static char osc_buffer[OSC_CHAR_MAX];
@@ -83,24 +114,35 @@ ansi_parser(const char *newdata, size_t len)
 	// Init Ragel on the first run
 	if (cs == -1) {
 		
-/* #line 87 "user/ansi_parser.c" */
+/* #line 118 "user/ansi_parser.c" */
 	{
 	cs = ansi_start;
 	}
 
-/* #line 57 "user/ansi_parser.rl" */
+/* #line 87 "user/ansi_parser.rl" */
+
+#if DEBUG_ANSI
+		memset(history, 0, sizeof(history));
+#endif
 	}
 
-	// schedule state reset
+	// schedule state reset after idle timeout
 	if (termconf->parser_tout_ms > 0) {
 		os_timer_disarm(&resetTim);
 		os_timer_setfn(&resetTim, resetParserCb, NULL);
 		os_timer_arm(&resetTim, termconf->parser_tout_ms, 0);
 	}
 
+#if DEBUG_ANSI
+	for(int i=len; i<HISTORY_LEN; i++) {
+		history[i-len] = history[i];
+	}
+	strcpy(&history[HISTORY_LEN-len], newdata);
+#endif
+
 	// The parser
 	
-/* #line 104 "user/ansi_parser.c" */
+/* #line 146 "user/ansi_parser.c" */
 	{
 	const char *_acts;
 	unsigned int _nacts;
@@ -117,201 +159,216 @@ case 1:
 	goto tr0;
 case 2:
 	switch( (*p) ) {
-		case 35: goto tr3;
-		case 91: goto tr5;
-		case 93: goto tr6;
-		case 107: goto tr7;
+		case 32: goto tr3;
+		case 35: goto tr4;
+		case 91: goto tr7;
+		case 93: goto tr8;
+		case 107: goto tr9;
 	}
-	if ( (*p) < 65 ) {
-		if ( 48 <= (*p) && (*p) <= 57 )
-			goto tr4;
-	} else if ( (*p) > 90 ) {
-		if ( 97 <= (*p) && (*p) <= 122 )
-			goto tr4;
+	if ( (*p) < 60 ) {
+		if ( (*p) > 47 ) {
+			if ( 48 <= (*p) && (*p) <= 57 )
+				goto tr6;
+		} else if ( (*p) >= 40 )
+			goto tr5;
+	} else if ( (*p) > 62 ) {
+		if ( (*p) > 90 ) {
+			if ( 97 <= (*p) && (*p) <= 122 )
+				goto tr6;
+		} else if ( (*p) >= 65 )
+			goto tr6;
 	} else
-		goto tr4;
+		goto tr6;
 	goto tr2;
 case 0:
 	goto _out;
 case 3:
-	if ( 48 <= (*p) && (*p) <= 57 )
-		goto tr8;
+	if ( 70 <= (*p) && (*p) <= 71 )
+		goto tr10;
 	goto tr2;
-case 28:
+case 30:
 	if ( (*p) == 27 )
 		goto tr1;
 	goto tr0;
 case 4:
+	if ( 48 <= (*p) && (*p) <= 57 )
+		goto tr11;
+	goto tr2;
+case 5:
 	switch( (*p) ) {
-		case 59: goto tr11;
-		case 64: goto tr12;
+		case 59: goto tr14;
+		case 64: goto tr15;
 	}
 	if ( (*p) < 60 ) {
 		if ( (*p) > 47 ) {
 			if ( 48 <= (*p) && (*p) <= 57 )
-				goto tr10;
+				goto tr13;
 		} else if ( (*p) >= 32 )
-			goto tr9;
+			goto tr12;
 	} else if ( (*p) > 63 ) {
 		if ( (*p) > 90 ) {
 			if ( 96 <= (*p) && (*p) <= 122 )
-				goto tr13;
+				goto tr16;
 		} else if ( (*p) >= 65 )
-			goto tr13;
+			goto tr16;
 	} else
-		goto tr9;
+		goto tr12;
 	goto tr2;
-case 5:
+case 6:
 	if ( (*p) == 59 )
-		goto tr11;
+		goto tr14;
 	if ( (*p) < 64 ) {
 		if ( 48 <= (*p) && (*p) <= 57 )
-			goto tr10;
+			goto tr13;
 	} else if ( (*p) > 90 ) {
 		if ( 96 <= (*p) && (*p) <= 122 )
-			goto tr13;
+			goto tr16;
 	} else
-		goto tr13;
+		goto tr16;
 	goto tr2;
-case 29:
+case 31:
 	goto tr2;
-case 30:
+case 32:
 	if ( (*p) == 59 )
-		goto tr11;
+		goto tr14;
 	if ( (*p) < 64 ) {
 		if ( 48 <= (*p) && (*p) <= 57 )
-			goto tr10;
+			goto tr13;
 	} else if ( (*p) > 90 ) {
 		if ( 96 <= (*p) && (*p) <= 122 )
-			goto tr13;
+			goto tr16;
 	} else
-		goto tr13;
+		goto tr16;
 	goto tr2;
-case 6:
+case 7:
 	switch( (*p) ) {
-		case 48: goto tr14;
-		case 66: goto tr15;
-		case 84: goto tr16;
-		case 87: goto tr17;
+		case 48: goto tr17;
+		case 66: goto tr18;
+		case 84: goto tr19;
+		case 87: goto tr20;
 	}
 	goto tr2;
-case 7:
+case 8:
 	if ( (*p) == 59 )
-		goto tr18;
+		goto tr21;
 	goto tr2;
-case 8:
+case 9:
 	switch( (*p) ) {
-		case 7: goto tr20;
-		case 27: goto tr21;
+		case 7: goto tr23;
+		case 27: goto tr24;
 	}
-	goto tr19;
-case 31:
+	goto tr22;
+case 33:
 	switch( (*p) ) {
-		case 7: goto tr20;
-		case 27: goto tr21;
+		case 7: goto tr23;
+		case 27: goto tr24;
 	}
-	goto tr19;
-case 9:
+	goto tr22;
+case 10:
 	if ( (*p) == 92 )
-		goto tr22;
+		goto tr25;
 	goto tr2;
-case 32:
+case 34:
 	goto tr2;
-case 10:
+case 11:
 	if ( (*p) == 84 )
-		goto tr23;
+		goto tr26;
 	goto tr2;
-case 11:
+case 12:
 	if ( (*p) == 78 )
-		goto tr24;
+		goto tr27;
 	goto tr2;
-case 12:
+case 13:
 	if ( 48 <= (*p) && (*p) <= 57 )
-		goto tr25;
+		goto tr28;
 	goto tr2;
-case 13:
+case 14:
 	if ( (*p) == 61 )
-		goto tr26;
+		goto tr29;
 	goto tr2;
-case 14:
+case 15:
 	switch( (*p) ) {
-		case 7: goto tr28;
-		case 27: goto tr29;
+		case 7: goto tr31;
+		case 27: goto tr32;
 	}
-	goto tr27;
-case 33:
+	goto tr30;
+case 35:
 	switch( (*p) ) {
-		case 7: goto tr28;
-		case 27: goto tr29;
+		case 7: goto tr31;
+		case 27: goto tr32;
 	}
-	goto tr27;
-case 15:
-	if ( (*p) == 92 )
-		goto tr30;
-	goto tr2;
+	goto tr30;
 case 16:
-	if ( (*p) == 73 )
-		goto tr31;
+	if ( (*p) == 92 )
+		goto tr33;
 	goto tr2;
 case 17:
-	if ( (*p) == 84 )
-		goto tr32;
+	if ( (*p) == 73 )
+		goto tr34;
 	goto tr2;
 case 18:
-	if ( (*p) == 76 )
-		goto tr33;
+	if ( (*p) == 84 )
+		goto tr35;
 	goto tr2;
 case 19:
-	if ( (*p) == 69 )
-		goto tr34;
+	if ( (*p) == 76 )
+		goto tr36;
 	goto tr2;
 case 20:
-	if ( (*p) == 61 )
-		goto tr35;
+	if ( (*p) == 69 )
+		goto tr37;
 	goto tr2;
 case 21:
-	if ( 48 <= (*p) && (*p) <= 57 )
-		goto tr36;
+	if ( (*p) == 61 )
+		goto tr38;
 	goto tr2;
 case 22:
-	if ( (*p) == 59 )
-		goto tr37;
 	if ( 48 <= (*p) && (*p) <= 57 )
-		goto tr36;
+		goto tr39;
 	goto tr2;
 case 23:
+	if ( (*p) == 59 )
+		goto tr40;
 	if ( 48 <= (*p) && (*p) <= 57 )
-		goto tr38;
+		goto tr39;
 	goto tr2;
 case 24:
+	if ( 48 <= (*p) && (*p) <= 57 )
+		goto tr41;
+	goto tr2;
+case 25:
 	switch( (*p) ) {
-		case 7: goto tr39;
-		case 27: goto tr40;
+		case 7: goto tr42;
+		case 27: goto tr43;
 	}
 	if ( 48 <= (*p) && (*p) <= 57 )
-		goto tr38;
+		goto tr41;
 	goto tr2;
-case 25:
+case 26:
 	if ( (*p) == 92 )
-		goto tr39;
+		goto tr42;
 	goto tr2;
-case 26:
+case 27:
 	switch( (*p) ) {
-		case 7: goto tr42;
-		case 27: goto tr43;
+		case 7: goto tr45;
+		case 27: goto tr46;
 	}
-	goto tr41;
-case 34:
+	goto tr44;
+case 36:
 	switch( (*p) ) {
-		case 7: goto tr42;
-		case 27: goto tr43;
+		case 7: goto tr45;
+		case 27: goto tr46;
 	}
-	goto tr41;
-case 27:
+	goto tr44;
+case 28:
 	if ( (*p) == 92 )
-		goto tr44;
+		goto tr47;
 	goto tr2;
-case 35:
+case 37:
+	goto tr2;
+case 29:
+	goto tr48;
+case 38:
 	goto tr2;
 	}
 
@@ -319,101 +376,112 @@ case 35:
 	tr0: cs = 1; goto f1;
 	tr1: cs = 2; goto _again;
 	tr3: cs = 3; goto _again;
-	tr9: cs = 5; goto f7;
-	tr10: cs = 5; goto f8;
-	tr11: cs = 5; goto f9;
-	tr14: cs = 7; goto _again;
-	tr18: cs = 8; goto _again;
-	tr19: cs = 8; goto f12;
+	tr4: cs = 4; goto _again;
+	tr12: cs = 6; goto f9;
+	tr13: cs = 6; goto f10;
+	tr14: cs = 6; goto f11;
+	tr17: cs = 8; goto _again;
 	tr21: cs = 9; goto _again;
-	tr15: cs = 10; goto _again;
-	tr23: cs = 11; goto _again;
-	tr24: cs = 12; goto _again;
-	tr25: cs = 13; goto f8;
-	tr26: cs = 14; goto _again;
-	tr27: cs = 14; goto f12;
+	tr22: cs = 9; goto f14;
+	tr24: cs = 10; goto _again;
+	tr18: cs = 11; goto _again;
+	tr26: cs = 12; goto _again;
+	tr27: cs = 13; goto _again;
+	tr28: cs = 14; goto f10;
 	tr29: cs = 15; goto _again;
-	tr16: cs = 16; goto _again;
-	tr31: cs = 17; goto _again;
-	tr32: cs = 18; goto _again;
-	tr33: cs = 19; goto _again;
-	tr34: cs = 20; goto _again;
-	tr17: cs = 21; goto _again;
-	tr36: cs = 22; goto f8;
-	tr37: cs = 23; goto f9;
-	tr38: cs = 24; goto f8;
-	tr40: cs = 25; goto _again;
-	tr41: cs = 26; goto f12;
-	tr43: cs = 27; goto _again;
-	tr4: cs = 28; goto f2;
-	tr5: cs = 28; goto f3;
-	tr6: cs = 28; goto f4;
-	tr7: cs = 28; goto f5;
-	tr8: cs = 28; goto f6;
-	tr13: cs = 29; goto f11;
-	tr12: cs = 30; goto f10;
-	tr20: cs = 31; goto f13;
-	tr35: cs = 32; goto f5;
-	tr22: cs = 32; goto f14;
-	tr30: cs = 32; goto f16;
-	tr39: cs = 32; goto f17;
-	tr28: cs = 33; goto f15;
-	tr42: cs = 34; goto f13;
-	tr44: cs = 35; goto f14;
+	tr30: cs = 15; goto f14;
+	tr32: cs = 16; goto _again;
+	tr19: cs = 17; goto _again;
+	tr34: cs = 18; goto _again;
+	tr35: cs = 19; goto _again;
+	tr36: cs = 20; goto _again;
+	tr37: cs = 21; goto _again;
+	tr20: cs = 22; goto _again;
+	tr39: cs = 23; goto f10;
+	tr40: cs = 24; goto f11;
+	tr41: cs = 25; goto f10;
+	tr43: cs = 26; goto _again;
+	tr44: cs = 27; goto f14;
+	tr46: cs = 28; goto _again;
+	tr5: cs = 30; goto f2;
+	tr6: cs = 30; goto f3;
+	tr7: cs = 30; goto f4;
+	tr8: cs = 30; goto f5;
+	tr9: cs = 30; goto f6;
+	tr10: cs = 30; goto f7;
+	tr11: cs = 30; goto f8;
+	tr16: cs = 31; goto f13;
+	tr15: cs = 32; goto f12;
+	tr23: cs = 33; goto f15;
+	tr38: cs = 34; goto f6;
+	tr25: cs = 34; goto f16;
+	tr33: cs = 34; goto f18;
+	tr42: cs = 34; goto f19;
+	tr31: cs = 35; goto f17;
+	tr45: cs = 36; goto f15;
+	tr47: cs = 37; goto f16;
+	tr48: cs = 38; goto f20;
 
 	f1: _acts = _ansi_actions + 1; goto execFuncs;
-	f3: _acts = _ansi_actions + 3; goto execFuncs;
-	f7: _acts = _ansi_actions + 5; goto execFuncs;
-	f8: _acts = _ansi_actions + 7; goto execFuncs;
-	f9: _acts = _ansi_actions + 9; goto execFuncs;
-	f11: _acts = _ansi_actions + 11; goto execFuncs;
+	f4: _acts = _ansi_actions + 3; goto execFuncs;
+	f9: _acts = _ansi_actions + 5; goto execFuncs;
+	f10: _acts = _ansi_actions + 7; goto execFuncs;
+	f11: _acts = _ansi_actions + 9; goto execFuncs;
+	f13: _acts = _ansi_actions + 11; goto execFuncs;
 	f0: _acts = _ansi_actions + 13; goto execFuncs;
-	f4: _acts = _ansi_actions + 15; goto execFuncs;
-	f5: _acts = _ansi_actions + 17; goto execFuncs;
-	f17: _acts = _ansi_actions + 19; goto execFuncs;
-	f12: _acts = _ansi_actions + 21; goto execFuncs;
-	f14: _acts = _ansi_actions + 23; goto execFuncs;
-	f16: _acts = _ansi_actions + 25; goto execFuncs;
-	f6: _acts = _ansi_actions + 27; goto execFuncs;
-	f2: _acts = _ansi_actions + 29; goto execFuncs;
-	f10: _acts = _ansi_actions + 31; goto execFuncs;
-	f13: _acts = _ansi_actions + 34; goto execFuncs;
-	f15: _acts = _ansi_actions + 37; goto execFuncs;
+	f5: _acts = _ansi_actions + 15; goto execFuncs;
+	f6: _acts = _ansi_actions + 17; goto execFuncs;
+	f19: _acts = _ansi_actions + 19; goto execFuncs;
+	f14: _acts = _ansi_actions + 21; goto execFuncs;
+	f16: _acts = _ansi_actions + 23; goto execFuncs;
+	f18: _acts = _ansi_actions + 25; goto execFuncs;
+	f8: _acts = _ansi_actions + 27; goto execFuncs;
+	f3: _acts = _ansi_actions + 29; goto execFuncs;
+	f7: _acts = _ansi_actions + 31; goto execFuncs;
+	f2: _acts = _ansi_actions + 33; goto execFuncs;
+	f20: _acts = _ansi_actions + 35; goto execFuncs;
+	f12: _acts = _ansi_actions + 37; goto execFuncs;
+	f15: _acts = _ansi_actions + 40; goto execFuncs;
+	f17: _acts = _ansi_actions + 43; goto execFuncs;
 
 execFuncs:
 	_nacts = *_acts++;
 	while ( _nacts-- > 0 ) {
 		switch ( *_acts++ ) {
 	case 0:
-/* #line 76 "user/ansi_parser.rl" */
+/* #line 117 "user/ansi_parser.rl" */
 	{
-			apars_handle_plainchar((*p));
+			if ((*p) != 0) {
+				apars_handle_plainchar((*p));
+			}
 		}
 	break;
 	case 1:
-/* #line 83 "user/ansi_parser.rl" */
+/* #line 126 "user/ansi_parser.rl" */
 	{
 			// Reset the CSI builder
 			csi_leading = csi_char = 0;
 			csi_ni = 0;
+			csi_cnt = 0;
 
 			// Zero out digits
 			for(int i = 0; i < CSI_N_MAX; i++) {
 				csi_n[i] = 0;
 			}
 
-			{cs = 4;goto _again;}
+			{cs = 5;goto _again;}
 		}
 	break;
 	case 2:
-/* #line 96 "user/ansi_parser.rl" */
+/* #line 140 "user/ansi_parser.rl" */
 	{
 			csi_leading = (*p);
 		}
 	break;
 	case 3:
-/* #line 100 "user/ansi_parser.rl" */
+/* #line 144 "user/ansi_parser.rl" */
 	{
+			if (csi_cnt == 0) csi_cnt = 1;
 			// x10 + digit
 			if (csi_ni < CSI_N_MAX) {
 				csi_n[csi_ni] = csi_n[csi_ni]*10 + ((*p) - '0');
@@ -421,30 +489,31 @@ execFuncs:
 		}
 	break;
 	case 4:
-/* #line 107 "user/ansi_parser.rl" */
+/* #line 152 "user/ansi_parser.rl" */
 	{
+			if (csi_cnt == 0) csi_cnt = 1; // handle case when first arg is empty
+			csi_cnt++;
 			csi_ni++;
 		}
 	break;
 	case 5:
-/* #line 111 "user/ansi_parser.rl" */
+/* #line 158 "user/ansi_parser.rl" */
 	{
 			csi_char = (*p);
-
-			apars_handle_CSI(csi_leading, csi_n, csi_char);
-
+			apars_handle_CSI(csi_leading, csi_n, csi_cnt, csi_char);
 			{cs = 1;goto _again;}
 		}
 	break;
 	case 6:
-/* #line 119 "user/ansi_parser.rl" */
+/* #line 164 "user/ansi_parser.rl" */
 	{
+			ansi_warn("Invalid escape sequence discarded.");
 			apars_handle_badseq();
 			{cs = 1;goto _again;}
 		}
 	break;
 	case 7:
-/* #line 136 "user/ansi_parser.rl" */
+/* #line 182 "user/ansi_parser.rl" */
 	{
 			csi_ni = 0;
 
@@ -456,32 +525,32 @@ execFuncs:
 			osc_bi = 0;
 			osc_buffer[0] = '\0';
 
-			{cs = 6;goto _again;}
+			{cs = 7;goto _again;}
 		}
 	break;
 	case 8:
-/* #line 151 "user/ansi_parser.rl" */
+/* #line 197 "user/ansi_parser.rl" */
 	{
 			osc_bi = 0;
 			osc_buffer[0] = '\0';
-			{cs = 26;goto _again;}
+			{cs = 27;goto _again;}
 		}
 	break;
 	case 9:
-/* #line 157 "user/ansi_parser.rl" */
+/* #line 203 "user/ansi_parser.rl" */
 	{
 			apars_handle_OSC_SetScreenSize(csi_n[0], csi_n[1]);
 			{cs = 1;goto _again;}
 		}
 	break;
 	case 10:
-/* #line 162 "user/ansi_parser.rl" */
+/* #line 208 "user/ansi_parser.rl" */
 	{
 			osc_buffer[osc_bi++] = (*p);
 		}
 	break;
 	case 11:
-/* #line 166 "user/ansi_parser.rl" */
+/* #line 212 "user/ansi_parser.rl" */
 	{
 			osc_buffer[osc_bi++] = '\0';
 			apars_handle_OSC_SetTitle(osc_buffer);
@@ -489,7 +558,7 @@ execFuncs:
 		}
 	break;
 	case 12:
-/* #line 172 "user/ansi_parser.rl" */
+/* #line 218 "user/ansi_parser.rl" */
 	{
 			osc_buffer[osc_bi++] = '\0';
 			apars_handle_OSC_SetButton(csi_n[0], osc_buffer);
@@ -497,20 +566,42 @@ execFuncs:
 		}
 	break;
 	case 13:
-/* #line 204 "user/ansi_parser.rl" */
+/* #line 250 "user/ansi_parser.rl" */
 	{
 			apars_handle_hashCode((*p));
 			{cs = 1;goto _again;}
 		}
 	break;
 	case 14:
-/* #line 209 "user/ansi_parser.rl" */
+/* #line 255 "user/ansi_parser.rl" */
 	{
 			apars_handle_shortCode((*p));
 			{cs = 1;goto _again;}
 		}
 	break;
-/* #line 514 "user/ansi_parser.c" */
+	case 15:
+/* #line 260 "user/ansi_parser.rl" */
+	{
+			apars_handle_setXCtrls((*p));
+			{cs = 1;goto _again;}
+		}
+	break;
+	case 16:
+/* #line 265 "user/ansi_parser.rl" */
+	{
+			// abuse the buffer for storing the leading char
+			osc_buffer[0] = (*p);
+			{cs = 29;goto _again;}
+		}
+	break;
+	case 17:
+/* #line 271 "user/ansi_parser.rl" */
+	{
+			apars_handle_characterSet(osc_buffer[0], (*p));
+			{cs = 1;goto _again;}
+		}
+	break;
+/* #line 605 "user/ansi_parser.c" */
 		}
 	}
 	goto _again;
@@ -528,15 +619,16 @@ _again:
 	while ( __nacts-- > 0 ) {
 		switch ( *__acts++ ) {
 	case 6:
-/* #line 119 "user/ansi_parser.rl" */
+/* #line 164 "user/ansi_parser.rl" */
 	{
+			ansi_warn("Invalid escape sequence discarded.");
 			apars_handle_badseq();
 			{cs = 1;	if ( p == pe )
 		goto _test_eof;
 goto _again;}
 		}
 	break;
-/* #line 540 "user/ansi_parser.c" */
+/* #line 632 "user/ansi_parser.c" */
 		}
 	}
 	}
@@ -544,7 +636,7 @@ goto _again;}
 	_out: {}
 	}
 
-/* #line 229 "user/ansi_parser.rl" */
+/* #line 295 "user/ansi_parser.rl" */
 
 }
 
diff --git a/user/ansi_parser.h b/user/ansi_parser.h
index 10138f0..1b01c7e 100644
--- a/user/ansi_parser.h
+++ b/user/ansi_parser.h
@@ -8,14 +8,26 @@
 #define CSI_N_MAX 3
 #define OSC_CHAR_MAX TERM_TITLE_LEN
 
-extern void apars_handle_badseq(void);
 extern void apars_handle_plainchar(char c);
-extern void apars_handle_CSI(char leadchar, int *params, char keychar);
+extern void apars_handle_CSI(char leadchar, int *params, int count, char keychar);
 extern void apars_handle_OSC_SetScreenSize(int rows, int cols);
 extern void apars_handle_OSC_SetButton(int num, const char *buffer);
 extern void apars_handle_OSC_SetTitle(const char *buffer);
 extern void apars_handle_shortCode(char c);
 extern void apars_handle_hashCode(char c);
+extern void apars_handle_characterSet(char leadchar, char c);
+extern void apars_handle_setXCtrls(char c);
+extern void apars_reset_utf8buffer(void);
+
+// defined in the makefile
+#if DEBUG_ANSI
+#define ansi_warn warn
+#define ansi_dbg warn
+#else
+#define ansi_warn(...)
+#define ansi_dbg(...)
+#endif
+
 
 /**
  * \brief Linear ANSI chars stream parser
@@ -32,4 +44,7 @@ extern void apars_handle_hashCode(char c);
  */
 void ansi_parser(const char *newdata, size_t len);
 
+/** This shows a short error message and prints the history (if any) */
+void apars_handle_badseq(void);
+
 #endif // ANSI_PARSER_H
diff --git a/user/ansi_parser.rl b/user/ansi_parser.rl
index cabd79b..c2cf454 100644
--- a/user/ansi_parser.rl
+++ b/user/ansi_parser.rl
@@ -16,10 +16,39 @@ static void ICACHE_FLASH_ATTR
 resetParserCb(void *arg) {
 	if (cs != ansi_start) {
 		cs = ansi_start;
-		warn("Parser timeout, state reset");
+		apars_reset_utf8buffer();
+		ansi_warn("Parser timeout, state reset");
 	}
 }
 
+#define HISTORY_LEN 16
+
+#if DEBUG_ANSI
+static char history[HISTORY_LEN + 1];
+#endif
+
+void ICACHE_FLASH_ATTR
+apars_handle_badseq(void)
+{
+#if DEBUG_ANSI
+	char buf1[HISTORY_LEN*3+2];
+	char buf2[HISTORY_LEN*3+2];
+	char *b1 = buf1;
+	char *b2 = buf2;
+	char c;
+
+	for(int i=0;i<HISTORY_LEN;i++) {
+		c = history[i];
+		b1 += sprintf(b1, "%2X ", c);
+		if (c < 32 || c > 127) c = '.';
+		b2 += sprintf(b2, "%c  ", c);
+	}
+
+	ansi_dbg("Context: %s", buf2);
+	ansi_dbg("         %s", buf1);
+#endif
+}
+
 /**
  * \brief Linear ANSI chars stream parser
  *
@@ -39,6 +68,7 @@ ansi_parser(const char *newdata, size_t len)
 	// The CSI code is built here
 	static char csi_leading;      //!< Leading char, 0 if none
 	static int  csi_ni;           //!< Number of the active digit
+	static int  csi_cnt;          //!< Digit count
 	static int  csi_n[CSI_N_MAX]; //!< Param digits
 	static char csi_char;         //!< CSI action char (end)
 	static char osc_buffer[OSC_CHAR_MAX];
@@ -54,15 +84,26 @@ ansi_parser(const char *newdata, size_t len)
 	// Init Ragel on the first run
 	if (cs == -1) {
 		%% write init;
+
+#if DEBUG_ANSI
+		memset(history, 0, sizeof(history));
+#endif
 	}
 
-	// schedule state reset
+	// schedule state reset after idle timeout
 	if (termconf->parser_tout_ms > 0) {
 		os_timer_disarm(&resetTim);
 		os_timer_setfn(&resetTim, resetParserCb, NULL);
 		os_timer_arm(&resetTim, termconf->parser_tout_ms, 0);
 	}
 
+#if DEBUG_ANSI
+	for(int i=len; i<HISTORY_LEN; i++) {
+		history[i-len] = history[i];
+	}
+	strcpy(&history[HISTORY_LEN-len], newdata);
+#endif
+
 	// The parser
 	%%{
 #/*
@@ -74,7 +115,9 @@ ansi_parser(const char *newdata, size_t len)
 		# --- Regular characters to be printed ---
 
 		action plain_char {
-			apars_handle_plainchar(fc);
+			if (fc != 0) {
+				apars_handle_plainchar(fc);
+			}
 		}
 
 		# --- CSI CSI commands (Select Graphic Rendition) ---
@@ -84,6 +127,7 @@ ansi_parser(const char *newdata, size_t len)
 			// Reset the CSI builder
 			csi_leading = csi_char = 0;
 			csi_ni = 0;
+			csi_cnt = 0;
 
 			// Zero out digits
 			for(int i = 0; i < CSI_N_MAX; i++) {
@@ -98,6 +142,7 @@ ansi_parser(const char *newdata, size_t len)
 		}
 
 		action CSI_digit {
+			if (csi_cnt == 0) csi_cnt = 1;
 			// x10 + digit
 			if (csi_ni < CSI_N_MAX) {
 				csi_n[csi_ni] = csi_n[csi_ni]*10 + (fc - '0');
@@ -105,18 +150,19 @@ ansi_parser(const char *newdata, size_t len)
 		}
 
 		action CSI_semi {
+			if (csi_cnt == 0) csi_cnt = 1; // handle case when first arg is empty
+			csi_cnt++;
 			csi_ni++;
 		}
 
 		action CSI_end {
 			csi_char = fc;
-
-			apars_handle_CSI(csi_leading, csi_n, csi_char);
-
+			apars_handle_CSI(csi_leading, csi_n, csi_cnt, csi_char);
 			fgoto main;
 		}
 
 		action errBadSeq {
+			ansi_warn("Invalid escape sequence discarded.");
 			apars_handle_badseq();
 			fgoto main;
 		}
@@ -211,6 +257,24 @@ ansi_parser(const char *newdata, size_t len)
 			fgoto main;
 		}
 
+		action SetXCtrls {
+			apars_handle_setXCtrls(fc);
+			fgoto main;
+		}
+
+		action CharsetCmd_start {
+			// abuse the buffer for storing the leading char
+			osc_buffer[0] = fc;
+			fgoto charsetcmd_body;
+		}
+
+		action CharsetCmd_end {
+			apars_handle_characterSet(osc_buffer[0], fc);
+			fgoto main;
+		}
+
+		charsetcmd_body := (any @CharsetCmd_end) $!errBadSeq;
+
 		# --- Main parser loop ---
 
 		main :=
@@ -220,7 +284,9 @@ ansi_parser(const char *newdata, size_t len)
 					(']' @OSC_start) |
 					('#' digit @HASH_code) |
 					('k' @SetTitle_start) |
-					([a-jl-zA-Z0-9] @SHORT_code)
+					([a-jl-zA-Z0-9=<>] @SHORT_code) |
+					([()*+-./] @CharsetCmd_start) |
+					(' ' [FG] @SetXCtrls)
 				)
 			)+ $!errBadSeq;
 
diff --git a/user/ansi_parser_callbacks.c b/user/ansi_parser_callbacks.c
index 05ac348..3fa86f2 100644
--- a/user/ansi_parser_callbacks.c
+++ b/user/ansi_parser_callbacks.c
@@ -39,28 +39,53 @@ apars_handle_plainchar(char c)
 			utf_j = 1;
 		}
 		else {
-			utf_collect[utf_j++] = c;
-			if (utf_j >= utf_i) {
-				screen_putchar(utf_collect);
-				utf_i = 0;
-				utf_j = 0;
-				memset(utf_collect, 0, 4);
+			if ((c & 0xC0) != 0x80) {
+				// bad UTF
+				ansi_warn("Bad UTF-8");
+				apars_reset_utf8buffer();
+			}
+			else {
+				utf_collect[utf_j++] = c;
+				if (utf_j >= utf_i) {
+					screen_putchar(utf_collect);
+					apars_reset_utf8buffer();
+				}
 			}
 		}
 	}
 	else {
+		if (c == 14 || c == 15) { // pushIn, pushOut
+			//ansi_warn("char %d ignored", c);
+			// TODO implement for charset switching
+			return;
+		}
+
 		utf_collect[0] = c;
 		utf_collect[1] = 0; // just to make sure it's closed...
 		screen_putchar(utf_collect);
 	}
 }
 
-/**
- * Bad sequence received, show warning
- */
-void apars_handle_badseq(void)
+void ICACHE_FLASH_ATTR
+apars_reset_utf8buffer(void)
+{
+	utf_i = 0;
+	utf_j = 0;
+	memset(utf_collect, 0, 4);
+}
+
+void ICACHE_FLASH_ATTR
+apars_handle_characterSet(char leadchar, char c)
+{
+	// TODO implement for charset switching
+//	ansi_warn("NOIMPL charset cmd %c%c", leadchar, c);
+}
+
+void ICACHE_FLASH_ATTR
+apars_handle_setXCtrls(char c)
 {
-	warn("Invalid escape sequence discarded.");
+	// this does not seem to do anything, sent by some unix programs
+//	ansi_warn("NOIMPL Select %cbit ctrls", c=='F'? '7':'8');
 }
 
 /**
@@ -70,7 +95,7 @@ void apars_handle_badseq(void)
  * \param keychar - the char terminating the sequence
  */
 void ICACHE_FLASH_ATTR
-apars_handle_CSI(char leadchar, int *params, char keychar)
+apars_handle_CSI(char leadchar, int *params, int count, char keychar)
 {
 	/*
 		Implemented codes (from Wikipedia)
@@ -216,38 +241,66 @@ apars_handle_CSI(char leadchar, int *params, char keychar)
 				// Query device status - reply "Device is OK"
 				UART_WriteString(UART0, "\033[0n", UART_TIMEOUT_US);
 			}
+			else {
+				ansi_warn("NOIMPL query %d", n1);
+			}
 			break;
 
 			// DECTCEM feature enable / disable
 
 		case 'h': // feature enable
 			if (leadchar == '?') {
-				if (n1 == 25) {
-					screen_cursor_enable(1);
-				} else if (n1 == 7) {
-					screen_wrap_enable(1);
+				if (n1 == 25) screen_cursor_enable(1);
+				else if (n1 == 7) screen_wrap_enable(1);
+				else if (n1 == 1) {
+					// TODO something with arrow keys??
+				}
+				else {
+					ansi_warn("NOIMPL DEC opt %d", n1);
+				}
+			}
+			else {
+				if (n1 == 4) {
+					// TODO insert mode, i think this is to suppress user input
+				}
+				else {
+					ansi_warn("NOIMPL flag %d", n1);
 				}
 			}
 			break;
 
 		case 'l': // feature disable
 			if (leadchar == '?') {
-				if (n1 == 25) {
-					screen_cursor_enable(0);
-				} else if (n1 == 7) {
-					screen_wrap_enable(0);
+				if (n1 == 25) screen_cursor_enable(0);
+				else if (n1 == 7) screen_wrap_enable(0);
+				else if (n1 == 1) {
+					// TODO see above
+				}
+				else {
+					ansi_warn("NOIMPL DEC opt %d", n1);
+				}
+			}
+			else {
+				if (n1 == 4) {
+					// TODO see above
+				}
+				else {
+					ansi_warn("NOIMPL flag %d", n1);
 				}
 			}
 			break;
 
 		case 'm': // SGR - graphics rendition aka attributes
+			if (count == 0) {
+				count = 1; // this makes it work as 0 (reset)
+			}
+
 			// iterate arguments
-			for (int i = 0; i < CSI_N_MAX; i++) {
+			for (int i = 0; i < count; i++) {
 				int n = params[i];
 
-				if (i == 0 && n == 0) { // reset SGR
+				if (n == 0) { // reset SGR
 					screen_reset_cursor(); // resets colors, inverse and bold.
-					break; // cannot combine reset with others - discard
 				}
 				else if (n >= 30 && n <= 37) screen_set_fg((Color) (n - 30)); // ANSI normal fg
 				else if (n >= 40 && n <= 47) screen_set_bg((Color) (n - 40)); // ANSI normal bg
@@ -259,6 +312,9 @@ apars_handle_CSI(char leadchar, int *params, char keychar)
 				else if (n == 21 || n == 22) screen_set_bold(false); // bold off
 				else if (n >= 90 && n <= 97) screen_set_fg((Color) (n - 90 + 8)); // AIX bright fg
 				else if (n >= 100 && n <= 107) screen_set_bg((Color) (n - 100 + 8)); // AIX bright bg
+				else {
+					ansi_warn("NOIMPL SGR attr %d", n);
+				}
 			}
 			break;
 
@@ -281,6 +337,30 @@ apars_handle_CSI(char leadchar, int *params, char keychar)
 		case 'P':
 			screen_delete_characters(n1);
 			break;
+
+		case 'r':
+			// TODO scrolling region
+			ansi_warn("NOIMPL scrolling region");
+			break;
+
+		case 'g':
+			// TODO clear tab
+			ansi_warn("NOIMPL clear tab");
+			break;
+
+		case 'Z':
+			// TODO back tab
+			ansi_warn("NOIMPL cursor back tab");
+			break;
+
+		case 'q':
+			// TODO setmode (??)
+			ansi_warn("NOIMPL CSI setmode %d", n1);
+			break;
+
+		default:
+			ansi_warn("Unknown CSI: %c", keychar);
+			apars_handle_badseq();
 	}
 }
 
@@ -291,6 +371,9 @@ void ICACHE_FLASH_ATTR apars_handle_hashCode(char c)
 		case '8':
 			screen_fill_with_E();
 			break;
+
+		default:
+			ansi_warn("Unknown # sequence: %c", c);
 	}
 }
 
@@ -301,22 +384,48 @@ void ICACHE_FLASH_ATTR apars_handle_shortCode(char c)
 		case 'c': // screen reset
 			screen_reset();
 			break;
+
 		case '7': // save cursor + attrs
 			screen_cursor_save(true);
 			break;
+
 		case '8': // restore cursor + attrs
 			screen_cursor_restore(true);
 			break;
+
 		case 'E': // same as CR LF
 			screen_cursor_move(1, 0, false);
 			screen_cursor_set_x(0);
 			break;
+
 		case 'D': // move cursor down, scroll screen up if needed
 			screen_cursor_move(1, 0, true);
 			break;
+
 		case 'M': // move cursor up, scroll screen down if needed
 			screen_cursor_move(-1, 0, true);
 			break;
+
+		case 'H':
+			// TODO set tab
+//			ansi_warn("NOIMPL set tab");
+			break;
+
+		// TODO those don't seem to do anything
+		case '>':
+//			ansi_warn("NOIMPL NUMKP");
+			break;
+
+		case '<':
+//			ansi_warn("NOIMPL SETANSI");
+			break;
+
+		case '=':
+//			ansi_warn("NOIMPL ALTKP");
+			break;
+
+		default:
+			ansi_warn("Unknown 1-char seq %c", c);
 	}
 }
 
diff --git a/user/ansi_parser_callbacks.h b/user/ansi_parser_callbacks.h
index 49b5c84..c0101f1 100644
--- a/user/ansi_parser_callbacks.h
+++ b/user/ansi_parser_callbacks.h
@@ -1,13 +1,15 @@
 #ifndef ANSI_PARSER_CALLBACKS_H
 #define ANSI_PARSER_CALLBACKS_H
 
-void apars_handle_badseq(void);
 void apars_handle_plainchar(char c);
-void apars_handle_CSI(char leadchar, int *params, char keychar);
+void apars_handle_CSI(char leadchar, int *params, int count, char keychar);
 void apars_handle_OSC_SetScreenSize(int rows, int cols);
 void apars_handle_OSC_SetButton(int num, const char *buffer);
 void apars_handle_OSC_SetTitle(const char *buffer);
 void apars_handle_shortCode(char c);
 void apars_handle_hashCode(char c);
+void apars_handle_characterSet(char leadchar, char c);
+void apars_handle_setXCtrls(char c);
+void apars_reset_utf8buffer(void);
 
 #endif //ESP_VT100_FIRMWARE_ANSI_PARSER_CALLBACKS_H
diff --git a/user/cgi_sockets.c b/user/cgi_sockets.c
index 1b9283d..b74a532 100644
--- a/user/cgi_sockets.c
+++ b/user/cgi_sockets.c
@@ -98,7 +98,7 @@ void ICACHE_FLASH_ATTR updateSockRx(Websock *ws, char *data, int len, int flags)
 
 	// TODO re-implement those, use single byte markers and B2 encoding
 
-	dbg("Sock RX str: %s, len %d", data, len);
+	ws_dbg("Sock RX str: %s, len %d", data, len);
 
 	if (strstarts(data, "STR:")) {
 		// pass string verbatim
@@ -134,24 +134,24 @@ void ICACHE_FLASH_ATTR updateSockRx(Websock *ws, char *data, int len, int flags)
 		}
 
 		if (!screen_isCoordValid(y, x)) {
-			warn("Mouse input at invalid coordinates");
+			ws_warn("Mouse input at invalid coordinates");
 			return;
 		}
 
-		dbg("Screen clicked at row %d, col %d", y+1, x+1);
+		ws_dbg("Screen clicked at row %d, col %d", y+1, x+1);
 
 		// Send as 1-based to user
 		sprintf(buf, "\033[%d;%dM", y+1, x+1);
 		UART_WriteString(UART0, buf, UART_TIMEOUT_US);
 	}
 	else {
-		warn("Bad command.");
+		ws_warn("Bad command.");
 	}
 }
 
 /** Socket connected for updates */
 void ICACHE_FLASH_ATTR updateSockConnect(Websock *ws)
 {
-	info("Socket connected to "URL_WS_UPDATE);
+	ws_info("Socket connected to "URL_WS_UPDATE);
 	ws->recvCb = updateSockRx;
 }
diff --git a/user/cgi_sockets.h b/user/cgi_sockets.h
index 8aebbc9..4b93046 100644
--- a/user/cgi_sockets.h
+++ b/user/cgi_sockets.h
@@ -9,4 +9,15 @@
 void updateSockConnect(Websock *ws);
 void screen_notifyChange(ScreenNotifyChangeTopic topic);
 
+// defined in the makefile
+#if DEBUG_INPUT
+#define ws_warn warn
+#define ws_dbg dbg
+#define ws_info info
+#else
+#define ws_warn(...)
+#define ws_dbg(...)
+#define ws_info(...)
+#endif
+
 #endif //CGI_SOCKETS_H
diff --git a/user/screen.c b/user/screen.c
index 9210684..74ebc00 100644
--- a/user/screen.c
+++ b/user/screen.c
@@ -186,12 +186,10 @@ screen_reset(void)
 void ICACHE_FLASH_ATTR
 screen_reset_cursor(void)
 {
-	NOTIFY_LOCK();
 	cursor.fg = termconf_scratch.default_fg;
 	cursor.bg = termconf_scratch.default_bg;
 	cursor.inverse = 0;
 	cursor.bold = 0;
-	NOTIFY_DONE();
 }
 
 /**
@@ -712,7 +710,7 @@ screen_putchar(const char *ch)
 		default:
 			if (ch[0] < ' ') {
 				// Discard
-				warn("Ignoring control char %d", (int)ch);
+				warn("Ignoring control char %d", (int)ch[0]);
 				goto done;
 			}
 	}