diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3c24afe..3855e8d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -124,7 +124,7 @@ set(SOURCE_FILES
         user/persist.h
         include/helpers.h
         user/syscfg.c
-        user/syscfg.h user/ascii.h)
+        user/syscfg.h user/ascii.h user/sgr.h)
 
 include_directories(include)
 include_directories(user)
diff --git a/Makefile b/Makefile
index f0c38ec..6e1a9d1 100644
--- a/Makefile
+++ b/Makefile
@@ -73,7 +73,7 @@ CFLAGS += -DADMIN_PASSWORD=$(ADMIN_PASSWORD)
 
 # Debug logging
 CFLAGS += -DDEBUG_ANSI=1
-CFLAGS += -DDEBUG_INPUT=0
+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 28f421b..b677b50 100644
--- a/user/ansi_parser.c
+++ b/user/ansi_parser.c
@@ -13,43 +13,43 @@ 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, 1, 
-	15, 1, 16, 1, 17, 2, 2, 5, 
-	2, 10, 11, 2, 10, 12
+	11, 1, 12, 1, 13, 1, 14, 2, 
+	3, 6, 2, 8, 9
 };
 
 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
+	0, 1, 1, 1, 1, 1, 1, 1, 
+	1, 1, 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 = 10;
 static const int ansi_error = 0;
 
 static const int ansi_en_CSI_body = 5;
-static const int ansi_en_OSC_body = 7;
-static const int ansi_en_TITLE_body = 25;
-static const int ansi_en_charsetcmd_body = 27;
+static const int ansi_en_StrCmd_body = 7;
+static const int ansi_en_charsetcmd_body = 9;
 static const int ansi_en_main = 1;
 
 
 /* #line 11 "user/ansi_parser.rl" */
 
 
+// Max nr of CSI parameters
+#define CSI_N_MAX 10
+#define STR_CHAR_MAX 64
+
 static volatile int cs = -1;
-static volatile bool inside_osc = false;
+static volatile bool inside_string = false;
 
+// public
 volatile u32 ansi_parser_char_cnt = 0;
 
 void ICACHE_FLASH_ATTR
 ansi_parser_reset(void) {
 	if (cs != ansi_start) {
 		cs = ansi_start;
-		inside_osc = false;
+		inside_string = false;
 		apars_reset_utf8buffer();
 		ansi_warn("Parser timeout, state reset");
 	}
@@ -100,13 +100,13 @@ void ICACHE_FLASH_ATTR
 ansi_parser(char newchar)
 {
 	// 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];
-	static int  osc_bi; // buffer char index
+	static char leadchar;
+	static int  arg_ni;
+	static int  arg_cnt;
+	static int  arg[CSI_N_MAX];
+	static char csi_char;
+	static char string_buffer[STR_CHAR_MAX];
+	static int  str_ni;
 
 	// This is used to detect timeout delay (time since last rx char)
 	ansi_parser_char_cnt++;
@@ -119,7 +119,7 @@ ansi_parser(char newchar)
 	cs = ansi_start;
 	}
 
-/* #line 87 "user/ansi_parser.rl" */
+/* #line 92 "user/ansi_parser.rl" */
 
 		#if DEBUG_ANSI
 			memset(history, 0, sizeof(history));
@@ -137,7 +137,7 @@ ansi_parser(char newchar)
 	if (newchar < ' ') {
 		switch (newchar) {
 			case ESC:
-				if (!inside_osc) {
+				if (!inside_string) {
 					// Reset state
 					cs = ansi_start;
 					// now the ESC will be processed by the parser
@@ -168,7 +168,7 @@ ansi_parser(char newchar)
 
 			case BEL:
 				// bel is also used to terminate OSC
-				if (!inside_osc) {
+				if (!inside_string) {
 					apars_handle_bel();
 					return;
 				}
@@ -224,21 +224,29 @@ case 2:
 	switch( (*p) ) {
 		case 32: goto tr3;
 		case 35: goto tr4;
-		case 91: goto tr7;
-		case 93: goto tr8;
-		case 107: goto tr9;
+		case 37: goto tr5;
+		case 80: goto tr7;
+		case 88: goto tr7;
+		case 91: goto tr8;
+		case 107: goto tr7;
 	}
-	if ( (*p) < 60 ) {
-		if ( (*p) > 47 ) {
-			if ( 48 <= (*p) && (*p) <= 57 )
+	if ( (*p) < 64 ) {
+		if ( (*p) < 48 ) {
+			if ( 40 <= (*p) && (*p) <= 47 )
+				goto tr5;
+		} else if ( (*p) > 57 ) {
+			if ( 60 <= (*p) && (*p) <= 62 )
 				goto tr6;
-		} else if ( (*p) >= 40 )
-			goto tr5;
-	} else if ( (*p) > 62 ) {
-		if ( (*p) > 90 ) {
-			if ( 97 <= (*p) && (*p) <= 122 )
+		} else
+			goto tr6;
+	} else if ( (*p) > 92 ) {
+		if ( (*p) < 97 ) {
+			if ( 93 <= (*p) && (*p) <= 95 )
+				goto tr7;
+		} else if ( (*p) > 122 ) {
+			if ( 124 <= (*p) && (*p) <= 126 )
 				goto tr6;
-		} else if ( (*p) >= 65 )
+		} else
 			goto tr6;
 	} else
 		goto tr6;
@@ -246,176 +254,89 @@ case 2:
 case 0:
 	goto _out;
 case 3:
-	if ( 70 <= (*p) && (*p) <= 71 )
-		goto tr10;
+	if ( (*p) > 71 ) {
+		if ( 76 <= (*p) && (*p) <= 78 )
+			goto tr9;
+	} else if ( (*p) >= 70 )
+		goto tr9;
 	goto tr2;
-case 28:
+case 10:
 	if ( (*p) == 27 )
 		goto tr1;
 	goto tr0;
 case 4:
 	if ( 48 <= (*p) && (*p) <= 57 )
-		goto tr11;
+		goto tr10;
 	goto tr2;
 case 5:
 	switch( (*p) ) {
-		case 59: goto tr14;
-		case 64: goto tr15;
+		case 59: goto tr13;
+		case 64: goto tr14;
 	}
 	if ( (*p) < 60 ) {
 		if ( (*p) > 47 ) {
 			if ( 48 <= (*p) && (*p) <= 57 )
-				goto tr13;
+				goto tr12;
 		} else if ( (*p) >= 32 )
-			goto tr12;
+			goto tr11;
 	} else if ( (*p) > 63 ) {
 		if ( (*p) > 90 ) {
 			if ( 96 <= (*p) && (*p) <= 122 )
-				goto tr16;
+				goto tr15;
 		} else if ( (*p) >= 65 )
-			goto tr16;
+			goto tr15;
 	} else
-		goto tr12;
+		goto tr11;
 	goto tr2;
 case 6:
 	if ( (*p) == 59 )
-		goto tr14;
+		goto tr13;
 	if ( (*p) < 64 ) {
 		if ( 48 <= (*p) && (*p) <= 57 )
-			goto tr13;
+			goto tr12;
 	} else if ( (*p) > 90 ) {
 		if ( 96 <= (*p) && (*p) <= 122 )
-			goto tr16;
+			goto tr15;
 	} else
-		goto tr16;
+		goto tr15;
 	goto tr2;
-case 29:
+case 11:
 	goto tr2;
-case 30:
+case 12:
 	if ( (*p) == 59 )
-		goto tr14;
+		goto tr13;
 	if ( (*p) < 64 ) {
 		if ( 48 <= (*p) && (*p) <= 57 )
-			goto tr13;
+			goto tr12;
 	} else if ( (*p) > 90 ) {
 		if ( 96 <= (*p) && (*p) <= 122 )
-			goto tr16;
+			goto tr15;
 	} else
-		goto tr16;
+		goto tr15;
 	goto tr2;
 case 7:
 	switch( (*p) ) {
-		case 48: goto tr17;
-		case 66: goto tr18;
-		case 84: goto tr19;
-		case 87: goto tr20;
+		case 7: goto tr17;
+		case 27: goto tr18;
 	}
-	goto tr2;
-case 8:
-	if ( (*p) == 59 )
-		goto tr21;
-	goto tr2;
-case 31:
-	goto tr2;
-case 9:
-	if ( (*p) == 84 )
-		goto tr22;
-	goto tr2;
-case 10:
-	if ( (*p) == 78 )
-		goto tr23;
-	goto tr2;
-case 11:
-	if ( 48 <= (*p) && (*p) <= 57 )
-		goto tr24;
-	goto tr2;
-case 12:
-	if ( (*p) == 61 )
-		goto tr25;
-	goto tr2;
+	goto tr16;
 case 13:
 	switch( (*p) ) {
-		case 7: goto tr27;
-		case 27: goto tr28;
-	}
-	goto tr26;
-case 32:
-	switch( (*p) ) {
-		case 7: goto tr27;
-		case 27: goto tr28;
-	}
-	goto tr26;
-case 14:
-	if ( (*p) == 92 )
-		goto tr29;
-	goto tr2;
-case 15:
-	if ( (*p) == 73 )
-		goto tr30;
-	goto tr2;
-case 16:
-	if ( (*p) == 84 )
-		goto tr31;
-	goto tr2;
-case 17:
-	if ( (*p) == 76 )
-		goto tr32;
-	goto tr2;
-case 18:
-	if ( (*p) == 69 )
-		goto tr33;
-	goto tr2;
-case 19:
-	if ( (*p) == 61 )
-		goto tr21;
-	goto tr2;
-case 20:
-	if ( 48 <= (*p) && (*p) <= 57 )
-		goto tr34;
-	goto tr2;
-case 21:
-	if ( (*p) == 59 )
-		goto tr35;
-	if ( 48 <= (*p) && (*p) <= 57 )
-		goto tr34;
-	goto tr2;
-case 22:
-	if ( 48 <= (*p) && (*p) <= 57 )
-		goto tr36;
-	goto tr2;
-case 23:
-	switch( (*p) ) {
-		case 7: goto tr37;
-		case 27: goto tr38;
+		case 7: goto tr17;
+		case 27: goto tr18;
 	}
-	if ( 48 <= (*p) && (*p) <= 57 )
-		goto tr36;
-	goto tr2;
-case 24:
-	if ( (*p) == 92 )
-		goto tr37;
-	goto tr2;
-case 25:
-	switch( (*p) ) {
-		case 7: goto tr40;
-		case 27: goto tr41;
-	}
-	goto tr39;
-case 33:
-	switch( (*p) ) {
-		case 7: goto tr40;
-		case 27: goto tr41;
-	}
-	goto tr39;
-case 26:
+	goto tr16;
+case 8:
 	if ( (*p) == 92 )
-		goto tr42;
+		goto tr19;
 	goto tr2;
-case 34:
+case 14:
 	goto tr2;
-case 27:
-	goto tr43;
-case 35:
+case 9:
+	if ( (*p) == 27 )
+		goto tr2;
+	goto tr20;
+case 15:
 	goto tr2;
 	}
 
@@ -424,232 +345,170 @@ case 35:
 	tr1: cs = 2; goto _again;
 	tr3: cs = 3; goto _again;
 	tr4: cs = 4; goto _again;
+	tr11: cs = 6; goto f8;
 	tr12: cs = 6; goto f9;
 	tr13: cs = 6; goto f10;
-	tr14: cs = 6; goto f11;
-	tr17: cs = 8; goto _again;
-	tr18: cs = 9; goto _again;
-	tr22: cs = 10; goto _again;
-	tr23: cs = 11; goto _again;
-	tr24: cs = 12; goto f10;
-	tr25: cs = 13; goto _again;
-	tr26: cs = 13; goto f14;
-	tr28: cs = 14; goto _again;
-	tr19: cs = 15; goto _again;
-	tr30: cs = 16; goto _again;
-	tr31: cs = 17; goto _again;
-	tr32: cs = 18; goto _again;
-	tr33: cs = 19; goto _again;
-	tr20: cs = 20; goto _again;
-	tr34: cs = 21; goto f10;
-	tr35: cs = 22; goto f11;
-	tr36: cs = 23; goto f10;
-	tr38: cs = 24; goto _again;
-	tr39: cs = 25; goto f14;
-	tr41: cs = 26; goto _again;
-	tr5: cs = 28; goto f2;
-	tr6: cs = 28; goto f3;
-	tr7: cs = 28; goto f4;
-	tr8: cs = 28; goto f5;
-	tr9: cs = 28; goto f6;
-	tr10: cs = 28; goto f7;
-	tr11: cs = 28; goto f8;
-	tr16: cs = 29; goto f13;
-	tr15: cs = 30; goto f12;
-	tr21: cs = 31; goto f6;
-	tr29: cs = 31; goto f16;
-	tr37: cs = 31; goto f17;
-	tr27: cs = 32; goto f15;
-	tr40: cs = 33; goto f18;
-	tr42: cs = 34; goto f19;
-	tr43: cs = 35; goto f20;
-
-	f1: _acts = _ansi_actions + 1; 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;
-	f5: _acts = _ansi_actions + 15; goto execFuncs;
-	f6: _acts = _ansi_actions + 17; goto execFuncs;
-	f17: _acts = _ansi_actions + 19; goto execFuncs;
-	f14: _acts = _ansi_actions + 21; goto execFuncs;
-	f19: _acts = _ansi_actions + 23; goto execFuncs;
-	f16: _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;
-	f18: _acts = _ansi_actions + 40; goto execFuncs;
-	f15: _acts = _ansi_actions + 43; goto execFuncs;
+	tr16: cs = 7; goto f13;
+	tr18: cs = 8; goto _again;
+	tr5: cs = 10; goto f2;
+	tr6: cs = 10; goto f3;
+	tr7: cs = 10; goto f4;
+	tr8: cs = 10; goto f5;
+	tr9: cs = 10; goto f6;
+	tr10: cs = 10; goto f7;
+	tr15: cs = 11; goto f12;
+	tr14: cs = 12; goto f11;
+	tr17: cs = 13; goto f14;
+	tr19: cs = 14; goto f15;
+	tr20: cs = 15; goto f16;
+
+	f0: _acts = _ansi_actions + 1; goto execFuncs;
+	f1: _acts = _ansi_actions + 3; goto execFuncs;
+	f5: _acts = _ansi_actions + 5; goto execFuncs;
+	f8: _acts = _ansi_actions + 7; goto execFuncs;
+	f9: _acts = _ansi_actions + 9; goto execFuncs;
+	f10: _acts = _ansi_actions + 11; goto execFuncs;
+	f12: _acts = _ansi_actions + 13; goto execFuncs;
+	f4: _acts = _ansi_actions + 15; goto execFuncs;
+	f13: _acts = _ansi_actions + 17; goto execFuncs;
+	f15: _acts = _ansi_actions + 19; goto execFuncs;
+	f7: _acts = _ansi_actions + 21; goto execFuncs;
+	f3: _acts = _ansi_actions + 23; goto execFuncs;
+	f6: _acts = _ansi_actions + 25; goto execFuncs;
+	f2: _acts = _ansi_actions + 27; goto execFuncs;
+	f16: _acts = _ansi_actions + 29; goto execFuncs;
+	f11: _acts = _ansi_actions + 31; goto execFuncs;
+	f14: _acts = _ansi_actions + 34; goto execFuncs;
 
 execFuncs:
 	_nacts = *_acts++;
 	while ( _nacts-- > 0 ) {
 		switch ( *_acts++ ) {
 	case 0:
-/* #line 180 "user/ansi_parser.rl" */
+/* #line 185 "user/ansi_parser.rl" */
+	{
+			ansi_warn("Parser error.");
+			apars_handle_badseq();
+			inside_string = false; // no longer in string, for sure
+			{cs = 1;goto _again;}
+		}
+	break;
+	case 1:
+/* #line 194 "user/ansi_parser.rl" */
 	{
 			if ((*p) != 0) {
 				apars_handle_plainchar((*p));
 			}
 		}
 	break;
-	case 1:
-/* #line 189 "user/ansi_parser.rl" */
+	case 2:
+/* #line 202 "user/ansi_parser.rl" */
 	{
 			// Reset the CSI builder
-			csi_leading = csi_char = 0;
-			csi_ni = 0;
-			csi_cnt = 0;
+			leadchar = 0;
+			arg_ni = 0;
+			arg_cnt = 0;
 
 			// Zero out digits
 			for(int i = 0; i < CSI_N_MAX; i++) {
-				csi_n[i] = 0;
+				arg[i] = 0;
 			}
 
 			{cs = 5;goto _again;}
 		}
 	break;
-	case 2:
-/* #line 203 "user/ansi_parser.rl" */
-	{
-			csi_leading = (*p);
-		}
-	break;
 	case 3:
-/* #line 207 "user/ansi_parser.rl" */
+/* #line 216 "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');
-			}
+			leadchar = (*p);
 		}
 	break;
 	case 4:
-/* #line 215 "user/ansi_parser.rl" */
+/* #line 220 "user/ansi_parser.rl" */
 	{
-			if (csi_cnt == 0) csi_cnt = 1; // handle case when first arg is empty
-			csi_cnt++;
-			csi_ni++;
+			if (arg_cnt == 0) arg_cnt = 1;
+			// x10 + digit
+			if (arg_ni < CSI_N_MAX) {
+				arg[arg_ni] = arg[arg_ni]*10 + ((*p) - '0');
+			}
 		}
 	break;
 	case 5:
-/* #line 221 "user/ansi_parser.rl" */
+/* #line 228 "user/ansi_parser.rl" */
 	{
-			csi_char = (*p);
-			apars_handle_CSI(csi_leading, csi_n, csi_cnt, csi_char);
-			{cs = 1;goto _again;}
+			if (arg_cnt == 0) arg_cnt = 1; // handle case when first arg is empty
+			arg_cnt++;
+			arg_ni++;
 		}
 	break;
 	case 6:
-/* #line 227 "user/ansi_parser.rl" */
+/* #line 234 "user/ansi_parser.rl" */
 	{
-			ansi_warn("Parser error.");
-			apars_handle_badseq();
+			apars_handle_CSI(leadchar, arg, arg_cnt, (*p));
 			{cs = 1;goto _again;}
 		}
 	break;
 	case 7:
 /* #line 245 "user/ansi_parser.rl" */
 	{
-			csi_ni = 0;
-
-			// we reuse the CSI numeric buffer
-			for(int i = 0; i < CSI_N_MAX; i++) {
-				csi_n[i] = 0;
-			}
-
-			osc_bi = 0;
-			osc_buffer[0] = '\0';
-
-			inside_osc = true;
-
+			leadchar = (*p);
+			str_ni = 0;
+			string_buffer[0] = '\0';
+			inside_string = true;
 			{cs = 7;goto _again;}
 		}
 	break;
 	case 8:
-/* #line 262 "user/ansi_parser.rl" */
+/* #line 253 "user/ansi_parser.rl" */
 	{
-			osc_bi = 0;
-			osc_buffer[0] = '\0';
-			inside_osc = true;
-			{cs = 25;goto _again;}
+			string_buffer[str_ni++] = (*p);
 		}
 	break;
 	case 9:
-/* #line 269 "user/ansi_parser.rl" */
+/* #line 257 "user/ansi_parser.rl" */
 	{
-			apars_handle_OSC_SetScreenSize(csi_n[0], csi_n[1]);
-			inside_osc = false;
+			inside_string = false;
+			string_buffer[str_ni++] = '\0';
+			apars_handle_StrCmd(leadchar, string_buffer);
 			{cs = 1;goto _again;}
 		}
 	break;
 	case 10:
-/* #line 275 "user/ansi_parser.rl" */
+/* #line 270 "user/ansi_parser.rl" */
 	{
-			osc_buffer[osc_bi++] = (*p);
+			apars_handle_hashCode((*p));
+			{cs = 1;goto _again;}
 		}
 	break;
 	case 11:
-/* #line 279 "user/ansi_parser.rl" */
+/* #line 275 "user/ansi_parser.rl" */
 	{
-			osc_buffer[osc_bi++] = '\0';
-			apars_handle_OSC_SetTitle(osc_buffer);
-			inside_osc = false;
+			apars_handle_shortCode((*p));
 			{cs = 1;goto _again;}
 		}
 	break;
 	case 12:
-/* #line 286 "user/ansi_parser.rl" */
+/* #line 280 "user/ansi_parser.rl" */
 	{
-			osc_buffer[osc_bi++] = '\0';
-			apars_handle_OSC_SetButton(csi_n[0], osc_buffer);
-			inside_osc = false;
+			apars_handle_spaceCmd((*p));
 			{cs = 1;goto _again;}
 		}
 	break;
 	case 13:
-/* #line 319 "user/ansi_parser.rl" */
+/* #line 287 "user/ansi_parser.rl" */
 	{
-			apars_handle_hashCode((*p));
-			{cs = 1;goto _again;}
+			leadchar = (*p);
+			{cs = 9;goto _again;}
 		}
 	break;
 	case 14:
-/* #line 324 "user/ansi_parser.rl" */
-	{
-			apars_handle_shortCode((*p));
-			{cs = 1;goto _again;}
-		}
-	break;
-	case 15:
-/* #line 329 "user/ansi_parser.rl" */
-	{
-			apars_handle_setXCtrls((*p)); // weird control settings like 7 bit / 8 bit mode
-			{cs = 1;goto _again;}
-		}
-	break;
-	case 16:
-/* #line 334 "user/ansi_parser.rl" */
-	{
-			// abuse the buffer for storing the leading char
-			osc_buffer[0] = (*p);
-			{cs = 27;goto _again;}
-		}
-	break;
-	case 17:
-/* #line 340 "user/ansi_parser.rl" */
+/* #line 292 "user/ansi_parser.rl" */
 	{
-			apars_handle_characterSet(osc_buffer[0], (*p));
+			apars_handle_characterSet(leadchar, (*p));
 			{cs = 1;goto _again;}
 		}
 	break;
-/* #line 653 "user/ansi_parser.c" */
+/* #line 512 "user/ansi_parser.c" */
 		}
 	}
 	goto _again;
@@ -666,17 +525,18 @@ _again:
 	unsigned int __nacts = (unsigned int) *__acts++;
 	while ( __nacts-- > 0 ) {
 		switch ( *__acts++ ) {
-	case 6:
-/* #line 227 "user/ansi_parser.rl" */
+	case 0:
+/* #line 185 "user/ansi_parser.rl" */
 	{
 			ansi_warn("Parser error.");
 			apars_handle_badseq();
+			inside_string = false; // no longer in string, for sure
 			{cs = 1;	if ( p == pe )
 		goto _test_eof;
 goto _again;}
 		}
 	break;
-/* #line 680 "user/ansi_parser.c" */
+/* #line 540 "user/ansi_parser.c" */
 		}
 	}
 	}
@@ -684,8 +544,6 @@ goto _again;}
 	_out: {}
 	}
 
-/* #line 364 "user/ansi_parser.rl" */
+/* #line 315 "user/ansi_parser.rl" */
 
 }
-
-// 'ESC k blah OSC_end' is a shortcut for setting title (k is defined in GNU screen as Title Definition String)
diff --git a/user/ansi_parser.h b/user/ansi_parser.h
index c922986..72a2bee 100644
--- a/user/ansi_parser.h
+++ b/user/ansi_parser.h
@@ -4,19 +4,13 @@
 #include <stdlib.h>
 #include <screen.h>
 
-// Max nr of CSI parameters
-#define CSI_N_MAX 10
-#define OSC_CHAR_MAX TERM_TITLE_LEN
-
 extern void apars_handle_plainchar(char c);
-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_CSI(char leadchar, const int *params, int count, char keychar);
+extern void apars_handle_StrCmd(char leadchar, 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_handle_spaceCmd(char c);
 extern void apars_reset_utf8buffer(void);
 extern void apars_handle_bel(void);
 
diff --git a/user/ansi_parser.rl b/user/ansi_parser.rl
index 321deba..6d1654b 100644
--- a/user/ansi_parser.rl
+++ b/user/ansi_parser.rl
@@ -10,16 +10,21 @@
 	write data;
 }%%
 
+// Max nr of CSI parameters
+#define CSI_N_MAX 10
+#define STR_CHAR_MAX 64
+
 static volatile int cs = -1;
-static volatile bool inside_osc = false;
+static volatile bool inside_string = false;
 
+// public
 volatile u32 ansi_parser_char_cnt = 0;
 
 void ICACHE_FLASH_ATTR
 ansi_parser_reset(void) {
 	if (cs != ansi_start) {
 		cs = ansi_start;
-		inside_osc = false;
+		inside_string = false;
 		apars_reset_utf8buffer();
 		ansi_warn("Parser timeout, state reset");
 	}
@@ -70,13 +75,13 @@ void ICACHE_FLASH_ATTR
 ansi_parser(char newchar)
 {
 	// 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];
-	static int  osc_bi; // buffer char index
+	static char leadchar;
+	static int  arg_ni;
+	static int  arg_cnt;
+	static int  arg[CSI_N_MAX];
+	static char csi_char;
+	static char string_buffer[STR_CHAR_MAX];
+	static int  str_ni;
 
 	// This is used to detect timeout delay (time since last rx char)
 	ansi_parser_char_cnt++;
@@ -101,7 +106,7 @@ ansi_parser(char newchar)
 	if (newchar < ' ') {
 		switch (newchar) {
 			case ESC:
-				if (!inside_osc) {
+				if (!inside_string) {
 					// Reset state
 					cs = ansi_start;
 					// now the ESC will be processed by the parser
@@ -132,7 +137,7 @@ ansi_parser(char newchar)
 
 			case BEL:
 				// bel is also used to terminate OSC
-				if (!inside_osc) {
+				if (!inside_string) {
 					apars_handle_bel();
 					return;
 				}
@@ -173,7 +178,16 @@ ansi_parser(char newchar)
 		ESC = 27;
 		NOESC = (any - ESC);
 		TOK_ST = ESC '\\'; # String terminator - used for OSC commands
-		OSC_END = ('\a' | TOK_ST);
+		STR_END = ('\a' | TOK_ST);
+
+		# --- Error handler ---
+
+		action errBadSeq {
+			ansi_warn("Parser error.");
+			apars_handle_badseq();
+			inside_string = false; // no longer in string, for sure
+			fgoto main;
+		}
 
 		# --- Regular characters to be printed ---
 
@@ -183,54 +197,42 @@ ansi_parser(char newchar)
 			}
 		}
 
-		# --- CSI CSI commands (Select Graphic Rendition) ---
-		# Text color & style
+		# --- CSI commands ---
 
 		action CSI_start {
 			// Reset the CSI builder
-			csi_leading = csi_char = 0;
-			csi_ni = 0;
-			csi_cnt = 0;
+			leadchar = 0;
+			arg_ni = 0;
+			arg_cnt = 0;
 
 			// Zero out digits
 			for(int i = 0; i < CSI_N_MAX; i++) {
-				csi_n[i] = 0;
+				arg[i] = 0;
 			}
 
 			fgoto CSI_body;
 		}
 
 		action CSI_leading {
-			csi_leading = fc;
+			leadchar = fc;
 		}
 
 		action CSI_digit {
-			if (csi_cnt == 0) csi_cnt = 1;
+			if (arg_cnt == 0) arg_cnt = 1;
 			// x10 + digit
-			if (csi_ni < CSI_N_MAX) {
-				csi_n[csi_ni] = csi_n[csi_ni]*10 + (fc - '0');
+			if (arg_ni < CSI_N_MAX) {
+				arg[arg_ni] = arg[arg_ni]*10 + (fc - '0');
 			}
 		}
 
 		action CSI_semi {
-			if (csi_cnt == 0) csi_cnt = 1; // handle case when first arg is empty
-			csi_cnt++;
-			csi_ni++;
+			if (arg_cnt == 0) arg_cnt = 1; // handle case when first arg is empty
+			arg_cnt++;
+			arg_ni++;
 		}
 
 		action CSI_end {
-			csi_char = fc;
-			apars_handle_CSI(csi_leading, csi_n, csi_cnt, csi_char);
-			fgoto main;
-		}
-
-		action errBadSeq {
-			ansi_warn("Parser error.");
-			apars_handle_badseq();
-			fgoto main;
-		}
-
-		action back2main {
+			apars_handle_CSI(leadchar, arg, arg_cnt, fc);
 			fgoto main;
 		}
 
@@ -238,83 +240,32 @@ ansi_parser(char newchar)
 			((digit @CSI_digit)* ';' @CSI_semi)*
 			(digit @CSI_digit)* (alpha|'`'|'@') @CSI_end $!errBadSeq;
 
+		# --- String commands ---
 
-		# --- OSC commands (Operating System Commands) ---
-		# Module parametrisation
-
-		action OSC_start {
-			csi_ni = 0;
-
-			// we reuse the CSI numeric buffer
-			for(int i = 0; i < CSI_N_MAX; i++) {
-				csi_n[i] = 0;
-			}
-
-			osc_bi = 0;
-			osc_buffer[0] = '\0';
-
-			inside_osc = true;
-
-			fgoto OSC_body;
+		action StrCmd_start {
+			leadchar = fc;
+			str_ni = 0;
+			string_buffer[0] = '\0';
+			inside_string = true;
+			fgoto StrCmd_body;
 		}
 
-		# collecting title string; this can also be entered by ESC k
-		action SetTitle_start {
-			osc_bi = 0;
-			osc_buffer[0] = '\0';
-			inside_osc = true;
-			fgoto TITLE_body;
+		action StrCmd_char {
+			string_buffer[str_ni++] = fc;
 		}
 
-		action OSC_resize {
-			apars_handle_OSC_SetScreenSize(csi_n[0], csi_n[1]);
-			inside_osc = false;
+		action StrCmd_end {
+			inside_string = false;
+			string_buffer[str_ni++] = '\0';
+			apars_handle_StrCmd(leadchar, string_buffer);
 			fgoto main;
 		}
 
-		action OSC_text_char {
-			osc_buffer[osc_bi++] = fc;
-		}
+		# According to the spec, ESC should be allowed inside the string sequence.
+		# We disallow ESC for simplicity, as it's hardly ever used.
+		StrCmd_body := ((NOESC @StrCmd_char)* STR_END @StrCmd_end) $!errBadSeq;
 
-		action OSC_title {
-			osc_buffer[osc_bi++] = '\0';
-			apars_handle_OSC_SetTitle(osc_buffer);
-			inside_osc = false;
-			fgoto main;
-		}
-
-		action OSC_button {
-			osc_buffer[osc_bi++] = '\0';
-			apars_handle_OSC_SetButton(csi_n[0], osc_buffer);
-			inside_osc = false;
-			fgoto main;
-		}
-
-		# 0; is xterm title hack
-		OSC_body := (
-			("BTN" digit @CSI_digit '=' (NOESC @OSC_text_char)* OSC_END @OSC_button) |
-			("TITLE=" @SetTitle_start) |
-			("0;" @SetTitle_start) |
-			('W' (digit @CSI_digit)+ ';' @CSI_semi (digit @CSI_digit)+ OSC_END @OSC_resize)
-		) $!errBadSeq;
-
-		TITLE_body := (NOESC @OSC_text_char)* OSC_END @OSC_title $!errBadSeq;
-
-		action RESET_cmd {
-			// Reset screen
-			apars_handle_RESET_cmd();
-			fgoto main;
-		}
-
-		action CSI_SaveCursorAttrs {
-			apars_handle_saveCursorAttrs();
-			fgoto main;
-		}
-
-		action CSI_RestoreCursorAttrs {
-			apars_handle_restoreCursorAttrs();
-			fgoto main;
-		}
+		# --- Single character ESC ---
 
 		action HASH_code {
 			apars_handle_hashCode(fc);
@@ -326,23 +277,24 @@ ansi_parser(char newchar)
 			fgoto main;
 		}
 
-		action SetXCtrls {
-			apars_handle_setXCtrls(fc); // weird control settings like 7 bit / 8 bit mode
+		action SPACE_cmd {
+			apars_handle_spaceCmd(fc);
 			fgoto main;
 		}
 
+		# --- Charset selection ---
+
 		action CharsetCmd_start {
-			// abuse the buffer for storing the leading char
-			osc_buffer[0] = fc;
+			leadchar = fc;
 			fgoto charsetcmd_body;
 		}
 
 		action CharsetCmd_end {
-			apars_handle_characterSet(osc_buffer[0], fc);
+			apars_handle_characterSet(leadchar, fc);
 			fgoto main;
 		}
 
-		charsetcmd_body := (any @CharsetCmd_end) $!errBadSeq;
+		charsetcmd_body := (NOESC @CharsetCmd_end) $!errBadSeq;
 
 		# --- Main parser loop ---
 
@@ -350,12 +302,11 @@ ansi_parser(char newchar)
 			(
 				(NOESC @plain_char)* ESC (
 					('[' @CSI_start) |
-					(']' @OSC_start) |
+					([_\]Pk\^X] @StrCmd_start) |
 					('#' digit @HASH_code) |
-					('k' @SetTitle_start) |
-					([a-jl-zA-Z0-9=<>] @SHORT_code) |
-					([()*+-./] @CharsetCmd_start) |
-					(' ' [FG] @SetXCtrls)
+					(([a-zA-Z0-9=<>~}|@\\] - [PXk]) @SHORT_code) |
+					([()*+-./%] @CharsetCmd_start) |
+					(' ' [FGLMN] @SPACE_cmd)
 				)
 			)+ $!errBadSeq;
 
@@ -363,5 +314,3 @@ ansi_parser(char newchar)
 #*/
 	}%%
 }
-
-// 'ESC k blah OSC_end' is a shortcut for setting title (k is defined in GNU screen as Title Definition String)
diff --git a/user/ansi_parser_callbacks.c b/user/ansi_parser_callbacks.c
index d12f308..e1b19ae 100644
--- a/user/ansi_parser_callbacks.c
+++ b/user/ansi_parser_callbacks.c
@@ -9,8 +9,7 @@
 #include "screen.h"
 #include "ansi_parser.h"
 #include "uart_driver.h"
-
-// screen manpage - https://www.gnu.org/software/screen/manual/html_node/Control-Sequences.html
+#include "sgr.h"
 
 static char utf_collect[4];
 static int utf_i = 0;
@@ -18,6 +17,7 @@ static int utf_j = 0;
 
 /**
  * Handle a received plain character
+ * @param c - received character
  */
 void ICACHE_FLASH_ATTR
 apars_handle_plainchar(char c)
@@ -68,11 +68,15 @@ apars_handle_plainchar(char c)
 	}
 
 	return;
-fail:
-	ansi_warn("Bad UTF-8: %0Xh", c);
+	fail:
+		ansi_warn("Bad UTF-8: %0Xh", c);
 	apars_reset_utf8buffer();
 }
 
+/**
+ * Clear the buffer where we collect pieces of a code point.
+ * This is used for parser reset.
+ */
 void ICACHE_FLASH_ATTR
 apars_reset_utf8buffer(void)
 {
@@ -81,36 +85,60 @@ apars_reset_utf8buffer(void)
 	memset(utf_collect, 0, 4);
 }
 
+/**
+ * Send a response to UART0
+ * @param str
+ */
+static void ICACHE_FLASH_ATTR
+respond(const char *str)
+{
+	UART_WriteString(UART0, str, UART_TIMEOUT_US);
+}
+
+/**
+ * Command to assign G0 or G1
+ * @param leadchar - ( or ) for G0 or G1
+ * @param c - character table ID (0, B etc)
+ */
 void ICACHE_FLASH_ATTR
 apars_handle_characterSet(char leadchar, char c)
 {
 	if (leadchar == '(') screen_set_charset(0, c);
 	else if (leadchar == ')') screen_set_charset(1, c);
+	else {
+		ansi_warn("NOIMPL: ESC %c %c", leadchar, c);
+	}
 	// other alternatives * + . - / not implemented
 }
 
-/** ESC SP <c> */
+/**
+ * ESC SP <c> (this sets 8/7-bit mode and some other archaic options)
+ * @param c - key character
+ */
 void ICACHE_FLASH_ATTR
-apars_handle_setXCtrls(char c)
+apars_handle_spaceCmd(char c)
 {
-	// this does not seem to do anything, sent by some unix programs
-//	ansi_warn("NOIMPL Select %cbit ctrls", c=='F'? '7':'8');
+	ansi_warn("NOIMPL: ESC SP %c", c);
 }
 
+/**
+ * Beep at the user.
+ */
 void ICACHE_FLASH_ATTR
 apars_handle_bel(void)
 {
+	ansi_warn("NOIMPL: BEEP");
 	// TODO pass to the browser somehow
 }
 
 /**
- * \brief Handle fully received CSI ANSI sequence
- * \param leadchar - private range leading character, 0 if none
- * \param params - array of CSI_N_MAX ints holding the numeric arguments
- * \param keychar - the char terminating the sequence
+ * Handle fully received CSI ANSI sequence
+ * @param leadchar - private range leading character, 0 if none
+ * @param params - array of CSI_N_MAX ints holding the numeric arguments
+ * @param keychar - the char terminating the sequence
  */
 void ICACHE_FLASH_ATTR
-apars_handle_CSI(char leadchar, int *params, int count, char keychar)
+apars_handle_CSI(char leadchar, const int *params, int count, char keychar)
 {
 	int n1 = params[0];
 	int n2 = params[1];
@@ -151,25 +179,29 @@ apars_handle_CSI(char leadchar, int *params, int count, char keychar)
 		case 'K':
 			if (n1 > 2) n1 = 0;
 			break;
+
+		default:
+			// leave as is
+			break;
 	}
 
 	switch (keychar) {
 		// CUU CUD CUF CUB
 		case 'a':
-		case 'A':
+		case 'A': // Up
 			screen_cursor_move(-n1, 0, false);
 			break;
 
 		case 'e':
-		case 'B':
+		case 'B': // Down
 			screen_cursor_move(n1, 0, false);
 			break;
 
-		case 'C':
+		case 'C': // Right (forward)
 			screen_cursor_move(0, n1, false);
 			break;
 
-		case 'D':
+		case 'D': // Left (backward)
 			screen_cursor_move(0, -n1, false);
 			break;
 
@@ -194,7 +226,7 @@ apars_handle_CSI(char leadchar, int *params, int count, char keychar)
 			screen_cursor_set_y(n1 - 1);
 			break; // 1-based
 
-			// clear in line
+			// Clear in line
 		case 'X':
 			screen_clear_in_line(n1);
 			break; // 1-based
@@ -209,7 +241,7 @@ apars_handle_CSI(char leadchar, int *params, int count, char keychar)
 			screen_cursor_set(n1-1, n2-1);
 			break; // 1-based
 
-		case 'J': // ED - clear screen
+		case 'J': // Erase screen
 			if (n1 == 0) {
 				screen_clear(CLEAR_FROM_CURSOR);
 			} else if (n1 == 1) {
@@ -220,7 +252,7 @@ apars_handle_CSI(char leadchar, int *params, int count, char keychar)
 			}
 			break;
 
-		case 'K': // EL - clear line
+		case 'K': // Erase lines
 			if (n1 == 0) {
 				screen_clear_line(CLEAR_FROM_CURSOR);
 			} else if (n1 == 1) {
@@ -234,28 +266,26 @@ apars_handle_CSI(char leadchar, int *params, int count, char keychar)
 		case 's': screen_cursor_save(0); break;
 		case 'u': screen_cursor_restore(0); break;
 
-		case 'n': // queries
+		case 'n': // Queries
 			if (n1 == 6) {
 				// Query cursor position
 				int x, y;
 				screen_cursor_get(&y, &x);
 				sprintf(buf, "\033[%d;%dR", y+1, x+1);
-				UART_WriteString(UART0, buf, UART_TIMEOUT_US);
+				respond(buf);
 			}
 			else if (n1 == 5) {
 				// Query device status - reply "Device is OK"
-				UART_WriteString(UART0, "\033[0n", UART_TIMEOUT_US);
+				respond("\033[0n");
 			}
 			else {
-				ansi_warn("NOIMPL query %d", n1);
+				ansi_warn("NOIMPL: CSI %d n", n1);
 			}
 			break;
 
-			// DECTCEM feature enable / disable
-
-		case 'h': // feature enable
+		case 'h': // DEC feature enable
 			yn = 1;
-		case 'l': // feature disable
+		case 'l': // DEC feature disable
 			for (int i = 0; i < count; i++) {
 				int n = params[i];
 				if (leadchar == '?') {
@@ -269,19 +299,36 @@ apars_handle_CSI(char leadchar, int *params, int count, char keychar)
 						screen_wrap_enable(yn);
 					}
 					else if (n == 8) {
-						// TODO autorepeat mode
+						// Key auto-repeat
+						// We don't implement this currently, but it could be added
+						// - discard repeated keypress events between keydown and keyup.
+					}
+					else if (n == 9 || (n >= 1000 && n <= 1006)) {
+						// TODO mouse
+						// 1000 - C11 mouse - Send Mouse X & Y on button press and release.
+						// 1001 - Hilite mouse tracking
+						// 1002 - Cell Motion Mouse Tracking
+						// 1003 - All Motion Mouse Tracking
+						// 1004 - Send FocusIn/FocusOut events
+						// 1005 - Enable UTF-8 Mouse Mode
+						// 1006 - SGR mouse mode
+					}
+					else if (n == 12) {
+						// TODO Cursor blink on/off
 					}
-					else if (n == 9) {
-						// TODO X10 mouse
+					else if (n == 1049) {
+						// XTERM: optionally switch to/from alternate screen
+						// We can't implement this because of limited RAM size
 					}
-					else if (n == 1000) {
-						// TODo X11 mouse
+					else if (n == 2004) {
+						// Bracketed paste mode
+						// Discard, we don't implement this
 					}
 					else if (n == 25) {
 						screen_cursor_visible(yn);
 					}
 					else {
-//						ansi_warn("NOIMPL DEC opt %d", n);
+						ansi_warn("NOIMPL: CSI ? %d %c", n, keychar);
 					}
 				}
 				else {
@@ -292,13 +339,13 @@ apars_handle_CSI(char leadchar, int *params, int count, char keychar)
 						screen_set_newline_mode(yn);
 					}
 					else {
-//						ansi_warn("NOIMPL flag %d", n);
+						ansi_warn("NOIMPL: CSI %d %c", n, keychar);
 					}
 				}
 			}
 			break;
 
-		case 'm': // SGR - graphics rendition aka attributes
+		case 'm': // SGR - set graphics rendition
 			if (count == 0) {
 				count = 1; // this makes it work as 0 (reset)
 			}
@@ -307,84 +354,85 @@ apars_handle_CSI(char leadchar, int *params, int count, char keychar)
 			for (int i = 0; i < count; i++) {
 				int n = params[i];
 
-				if (n == 0) { // reset SGR
-					screen_reset_sgr(); // resets colors, inverse and bold.
-				}
-				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
-				else if (n == 39) screen_set_fg(termconf_scratch.default_fg); // default fg
-				else if (n == 49) screen_set_bg(termconf_scratch.default_bg); // default bg
-
-				else if (n == 1) screen_attr_enable(ATTR_BOLD);
-				else if (n == 2) screen_attr_enable(ATTR_FAINT);
-				else if (n == 3) screen_attr_enable(ATTR_ITALIC);
-				else if (n == 4) screen_attr_enable(ATTR_UNDERLINE);
-				else if (n == 5 || n == 6) screen_attr_enable(ATTR_BLINK); // 6 - rapid blink, not supported
-				else if (n == 7) screen_inverse_enable(true);
-				else if (n == 9) screen_attr_enable(ATTR_STRIKE);
-
-				else if (n == 20) screen_attr_enable(ATTR_FRAKTUR);
-				else if (n == 21) screen_attr_disable(ATTR_BOLD);
-				else if (n == 22) screen_attr_disable(ATTR_FAINT);
-				else if (n == 23) screen_attr_disable(ATTR_ITALIC|ATTR_FRAKTUR);
-				else if (n == 24) screen_attr_disable(ATTR_UNDERLINE);
-				else if (n == 25) screen_attr_disable(ATTR_BLINK);
-				else if (n == 27) screen_inverse_enable(false);
-				else if (n == 29) screen_attr_disable(ATTR_STRIKE);
-
-				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
+				if (n == SGR_RESET) screen_reset_sgr();
+				// -- set color --
+				else if (n >= SGR_FG_START && n <= SGR_FG_END) screen_set_fg((Color) (n - SGR_FG_START)); // ANSI normal fg
+				else if (n >= SGR_BG_START && n <= SGR_BG_END) screen_set_bg((Color) (n - SGR_BG_START)); // ANSI normal bg
+				else if (n == SGR_FG_DEFAULT) screen_set_fg(termconf_scratch.default_fg); // default fg
+				else if (n == SGR_BG_DEFAULT) screen_set_bg(termconf_scratch.default_bg); // default bg
+				// -- set attr --
+				else if (n == SGR_BOLD) screen_attr_enable(ATTR_BOLD);
+				else if (n == SGR_FAINT) screen_attr_enable(ATTR_FAINT);
+				else if (n == SGR_ITALIC) screen_attr_enable(ATTR_ITALIC);
+				else if (n == SGR_UNDERLINE) screen_attr_enable(ATTR_UNDERLINE);
+				else if (n == SGR_BLINK || n == SGR_BLINK_FAST) screen_attr_enable(ATTR_BLINK); // 6 - rapid blink, not supported
+				else if (n == SGR_INVERSE) screen_inverse_enable(true);
+				else if (n == SGR_STRIKE) screen_attr_enable(ATTR_STRIKE);
+				else if (n == SGR_FRAKTUR) screen_attr_enable(ATTR_FRAKTUR);
+				// -- clear attr --
+				else if (n == SGR_OFF(SGR_BOLD)) screen_attr_disable(ATTR_BOLD);
+				else if (n == SGR_OFF(SGR_FAINT)) screen_attr_disable(ATTR_FAINT);
+				else if (n == SGR_OFF(SGR_ITALIC)) screen_attr_disable(ATTR_ITALIC|ATTR_FRAKTUR);
+				else if (n == SGR_OFF(SGR_UNDERLINE)) screen_attr_disable(ATTR_UNDERLINE);
+				else if (n == SGR_OFF(SGR_BLINK)) screen_attr_disable(ATTR_BLINK);
+				else if (n == SGR_OFF(SGR_INVERSE)) screen_inverse_enable(false);
+				else if (n == SGR_OFF(SGR_STRIKE)) screen_attr_disable(ATTR_STRIKE);
+				// -- AIX bright colors --
+				else if (n >= SGR_FG_BRT_START && n <= SGR_FG_BRT_END) screen_set_fg((Color) ((n - SGR_FG_BRT_START) + 8)); // AIX bright fg
+				else if (n >= SGR_BG_BRT_START && n <= SGR_BG_BRT_END) screen_set_bg((Color) ((n - SGR_BG_BRT_START) + 8)); // AIX bright bg
 				else {
-					ansi_warn("NOIMPL SGR attr %d", n);
+					ansi_warn("NOIMPL: SGR %d", n);
 				}
 			}
 			break;
 
-		case 't': // xterm hacks
+		case 't': // xterm window hacks
 			switch(n1) {
 				case 8: // set size
 					screen_resize(n2, n3);
 					break;
 				case 18: // report size
 					printf(buf, "\033[8;%d;%dt", termconf_scratch.height, termconf_scratch.width);
-					UART_WriteString(UART0, buf, UART_TIMEOUT_US);
+					respond(buf);
 					break;
 				case 11: // Report iconified -> is not iconified
-					UART_WriteString(UART0, "\033[1t", UART_TIMEOUT_US);
+					respond("\033[1t");
 					break;
 				case 21: // Report title
-					UART_WriteString(UART0, "\033]L", UART_TIMEOUT_US);
-					UART_WriteString(UART0, termconf_scratch.title, UART_TIMEOUT_US);
-					UART_WriteString(UART0, "\033\\", UART_TIMEOUT_US);
+					respond("\033]L");
+					respond(termconf_scratch.title);
+					respond("\033\\");
 					break;
 				case 24: // Set Height only
 					screen_resize(n2, termconf_scratch.width);
 					break;
+				default:
+					ansi_warn("NOIMPL CSI %d t", n1);
+					break;
 			}
 			break;
 
-		case 'L':
+		case 'L': // Insert lines (shove down)
 			screen_insert_lines(n1);
 			break;
 
-		case 'M':
+		case 'M': // Delete lines (pull up)
 			screen_delete_lines(n1);
 			break;
 
-		case '@':
+		case '@': // Insert in line (shove right)
 			screen_insert_characters(n1);
 			break;
 
-		case 'P':
+		case 'P': // Delete in line (pull left)
 			screen_delete_characters(n1);
 			break;
 
 		case 'r':
 			// TODO scrolling region
-//			ansi_warn("NOIMPL scrolling region");
 			break;
 
-		case 'g':
+		case 'g': // Clear tabs
 			if (n1 == 3) {
 				screen_clear_all_tabs();
 			} else {
@@ -392,30 +440,32 @@ apars_handle_CSI(char leadchar, int *params, int count, char keychar)
 			}
 			break;
 
-		case 'Z':
+		case 'Z': // Tab backward
 			for(; n1 > 0; n1--) {
 				screen_tab_reverse();
 			}
 			break;
 
-		case 'I':
+		case 'I': // Tab forward
 			for(; n1 > 0; n1--) {
 				screen_tab_forward();
 			}
 			break;
 
-		case 'c': // CSI-c
-			// report capabilities (pretend we're vt4xx)
-			UART_WriteString(UART0, "\033[?64;22;c", UART_TIMEOUT_US);
+		case 'c': // CSI-c - report capabilities
+			respond("\033[?64;22;c"); // pretend we're vt400
 			break;
 
 		default:
-			ansi_warn("Unknown CSI: %c", keychar);
+			ansi_warn("NOIMPL: CSI Pm %c", keychar);
 			apars_handle_badseq();
 	}
 }
 
-/** codes in the format ESC # n */
+/**
+ * Codes in the format ESC # n
+ * @param c - the trailing symbol (numeric ASCII)
+ */
 void ICACHE_FLASH_ATTR apars_handle_hashCode(char c)
 {
 	switch(c) {
@@ -424,11 +474,14 @@ void ICACHE_FLASH_ATTR apars_handle_hashCode(char c)
 			break;
 
 		default:
-			ansi_warn("Bad seq: ESC # %c", c);
+			ansi_warn("NOIMPL: ESC # %c", c);
 	}
 }
 
-/** those are single-character escape codes (ESC x) */
+/**
+ * Single-character escape codes (ESC x)
+ * @param c - the trailing symbol (ASCII)
+ */
 void ICACHE_FLASH_ATTR apars_handle_shortCode(char c)
 {
 	switch(c) {
@@ -469,43 +522,169 @@ void ICACHE_FLASH_ATTR apars_handle_shortCode(char c)
 			screen_set_numpad_alt_mode(false);
 			break;
 
-		case '<':
-			// "Enter ANSI / VT100 mode" - no-op
+		case '<': // "Enter ANSI / VT100 mode" - no-op (we don't support VT52 mode)
 			break;
 
 		case '=':
 			screen_set_numpad_alt_mode(true);
 			break;
 
+		case '|': // Invoke the G3 Character Set as GR (LS3R).
+		case '}': // Invoke the G2 Character Set as GR (LS2R).
+		case '~': // Invoke the G1 Character Set as GR (LS1R).
+			// Those do not seem to do anything TODO investigate
+			break;
+
+		case '@': // no-op padding char (?)
+			break;
+
+		case '\\': // spurious string terminator
+			break;
+
 		default:
-			ansi_warn("Bad seq: ESC %c", c);
+			ansi_warn("NOIMPL: ESC %c", c);
 	}
 }
 
 /**
- * Handle a screen resize request
+ * Helper function to set terminal title
+ * @param str - title text
  */
-void ICACHE_FLASH_ATTR
-apars_handle_OSC_SetScreenSize(int rows, int cols)
+static void ICACHE_FLASH_ATTR
+set_title(const char *str)
 {
-//	info("OSC: Set screen size to %d x %d", rows, cols);
+	strncpy(termconf_scratch.title, str, TERM_TITLE_LEN);
+	screen_notifyChange(CHANGE_LABELS);
+}
 
-	screen_resize(rows, cols);
+/**
+ * Helper function to set terminal button label
+ * @param num - button number 1-5
+ * @param str - button text
+ */
+static void ICACHE_FLASH_ATTR
+set_button_text(int num, const char *str)
+{
+	strncpy(termconf_scratch.btn[num-1], str, TERM_BTN_LEN);
+	screen_notifyChange(CHANGE_LABELS);
 }
 
+/**
+ * Helper function to parse incoming OSC (Operating System Control)
+ * @param buffer - the OSC body (after OSC and before ST)
+ */
+static void ICACHE_FLASH_ATTR
+parse_osc(const char *buffer)
+{
+	const char *orig_buff = buffer;
+	int n = 0;
+	char c = 0;
+	while ((c = *buffer++) != 0) {
+		if (c >= '0' && c <= '9') {
+			n = (n * 10 + (c - '0'));
+		} else {
+			break;
+		}
+	}
+
+	if (c == ';') {
+		// Do something with the data string and number
+		// (based on xterm manpage)
+		if (n == 0 || n == 2) set_title(buffer);
+		else if (n >= 81 && n <= 85) { // numbers chosen to not collide with any xterm supported codes
+			set_button_text(n - 80, buffer);
+		}
+		else {
+			ansi_warn("NOIMPL: OSC %d ; %s ST", n, buffer);
+		}
+	}
+	else {
+		ansi_warn("BAD OSC: %s", orig_buff);
+	}
+}
 
-void ICACHE_FLASH_ATTR
-apars_handle_OSC_SetButton(int num, const char *buffer)
+/**
+ * Helper function to parse incoming DCS (Device Control String)
+ * @param buffer - the DCS body (after DCS and before ST)
+ */
+static void ICACHE_FLASH_ATTR
+parse_dcs(const char *buffer)
 {
-	strncpy(termconf_scratch.btn[num-1], buffer, TERM_BTN_LEN);
-//	info("OSC: Set BTN%d = %s", num, buffer);
-	screen_notifyChange(CHANGE_LABELS);
+	char buf[64]; // just about big enough for full-house SGR
+	size_t len = strlen(buffer);
+	if ((len == 3 || len == 4) && strneq(buffer, "$q", 2)) {
+		// DECRQSS - Request Status String
+		if (strneq(buffer+2, "\"p", 2)) {
+			// DECSCL - Select Conformance Level
+			respond("\033[P1$r64;1\"p\033\\"); // 64;1 - Pretend we are VT400 with 7-bit characters
+		}
+		else if (strneq(buffer+2, "\"q", 2)) {
+			// DECSCA - Select character protection attribute
+			sprintf(buf, "\033[P1$r%d\"q\033\\", 0); // 0 - Can erase - TODO real protection status if implemented
+			respond(buf);
+		}
+		else if (buffer[2] == 'r') {
+			// DECSTBM - Query scrolling region
+			sprintf(buf, "\033[P1$r%d;%dr\033\\", 1, termconf_scratch.height); // 1-80 TODO real extent of scrolling region
+			respond(buf);
+		}
+		else if (buffer[2] == 's') {
+			// DECSLRM - Query horizontal margins
+			sprintf(buf, "\033[P1$r%d;%ds\033\\", 1, termconf_scratch.width); // Can erase - TODO real extent of horiz margins if implemented
+			respond(buf);
+		}
+		else if (buffer[2] == 'm') {
+			// SGR - query SGR
+			respond("\033[P1$r");
+			screen_report_sgr(buf);
+			respond(buf);
+			respond("m\033\\");
+		}
+		else if (strneq(buffer+2, " q", 2)) {
+			// DECSCUSR - Query cursor style
+			sprintf(buf, "\033[P1$r%d q\033\\", 1);
+			/*
+				Ps = 0  -> blinking block.
+				Ps = 1  -> blinking block (default).
+				Ps = 2  -> steady block.
+				Ps = 3  -> blinking underline.
+				Ps = 4  -> steady underline.
+				Ps = 5  -> blinking bar (xterm).
+				Ps = 6  -> steady bar (xterm).
+			 */
+			respond(buf);
+		}
+		else {
+			// invalid query
+			ansi_warn("NOIMPL: DCS %s ST", buffer);
+			sprintf(buf, "\033[P0$r%s\033\\", buffer+2);
+		}
+	}
+	else {
+		ansi_warn("NOIMPL: DCS %s ST", buffer);
+	}
 }
 
 void ICACHE_FLASH_ATTR
-apars_handle_OSC_SetTitle(const char *buffer)
+apars_handle_StrCmd(char leadchar, const char *buffer)
 {
-	strncpy(termconf_scratch.title, buffer, TERM_TITLE_LEN);
-//	info("OSC: Set TITLE = %s", buffer);
-	screen_notifyChange(CHANGE_LABELS);
+	switch (leadchar) {
+		case 'k': // ESC k TITLE ST (defined in GNU screen manpage)
+			set_title(buffer);
+			break;
+		case ']': // OSC - Operating System Command
+			parse_osc(buffer);
+			break;
+		case 'P': // DCS - Device Control String
+			parse_dcs(buffer);
+			break;
+		case '^': // PM - Privacy Message
+			break;
+		case '_': // APC - Application Program Command
+			break;
+		case 'X': // SOS - Start of String (purpose unclear)
+			break;
+		default:
+			ansi_warn("NOIMPL: ESC %c Pt ST", leadchar);
+	}
 }
diff --git a/user/ansi_parser_callbacks.h b/user/ansi_parser_callbacks.h
index 3126695..971decf 100644
--- a/user/ansi_parser_callbacks.h
+++ b/user/ansi_parser_callbacks.h
@@ -4,14 +4,12 @@
 #include "screen.h"
 
 void apars_handle_plainchar(char c);
-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_CSI(char leadchar, const int *params, int count, char keychar);
+void apars_handle_StrCmd(char leadchar, 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_handle_spaceCmd(char c);
 void apars_reset_utf8buffer(void);
 void apars_handle_bel(void);
 
diff --git a/user/screen.c b/user/screen.c
index 75bbf01..8cc75f6 100644
--- a/user/screen.c
+++ b/user/screen.c
@@ -2,6 +2,7 @@
 #include <httpd.h>
 #include "screen.h"
 #include "persist.h"
+#include "sgr.h"
 
 TerminalConfigBundle * const termconf = &persist.current.termconf;
 TerminalConfigBundle termconf_scratch;
@@ -834,6 +835,22 @@ screen_set_newline_mode(bool nlm)
 	scr.newline_mode = nlm;
 }
 
+void ICACHE_FLASH_ATTR
+screen_report_sgr(char *buffer)
+{
+	buffer += sprintf(buffer, "0");
+	if (cursor.attrs & ATTR_BOLD) buffer += sprintf(buffer, ";%d", SGR_BOLD);
+	if (cursor.attrs & ATTR_FAINT) buffer += sprintf(buffer, ";%d", SGR_FAINT);
+	if (cursor.attrs & ATTR_ITALIC) buffer += sprintf(buffer, ";%d", SGR_ITALIC);
+	if (cursor.attrs & ATTR_UNDERLINE) buffer += sprintf(buffer, ";%d", SGR_UNDERLINE);
+	if (cursor.attrs & ATTR_BLINK) buffer += sprintf(buffer, ";%d", SGR_BLINK);
+	if (cursor.attrs & ATTR_FRAKTUR) buffer += sprintf(buffer, ";%d", SGR_FRAKTUR);
+	if (cursor.attrs & ATTR_STRIKE) buffer += sprintf(buffer, ";%d", SGR_STRIKE);
+	if (cursor.inverse) buffer += sprintf(buffer, ";%d", SGR_INVERSE);
+	if (cursor.fg != termconf->default_fg) buffer += sprintf(buffer, ";%d", ((cursor.fg > 7) ? SGR_FG_BRT_START : SGR_FG_START) + (cursor.fg&7));
+	if (cursor.bg != termconf->default_bg) buffer += sprintf(buffer, ";%d", ((cursor.bg > 7) ? SGR_BG_BRT_START : SGR_BG_START) + (cursor.bg&7));
+}
+
 //endregion
 
 //region --- Printing ---
diff --git a/user/screen.h b/user/screen.h
index ac04573..d745c62 100644
--- a/user/screen.h
+++ b/user/screen.h
@@ -90,6 +90,7 @@ void terminal_restore_defaults(void);
 void terminal_apply_settings(void);
 void terminal_apply_settings_noclear(void); // the same, but with no screen reset / init
 
+void screen_report_sgr(char *buffer);
 
 typedef enum {
 	CLEAR_TO_CURSOR=0, CLEAR_FROM_CURSOR=1, CLEAR_ALL=2
diff --git a/user/sgr.h b/user/sgr.h
new file mode 100644
index 0000000..d87c3df
--- /dev/null
+++ b/user/sgr.h
@@ -0,0 +1,37 @@
+//
+// Created by MightyPork on 2017/08/19.
+//
+
+#ifndef ESP_VT100_FIRMWARE_SGR_H
+#define ESP_VT100_FIRMWARE_SGR_H
+
+enum SGR_CODES {
+	SGR_RESET = 0,
+	SGR_BOLD = 1,
+	SGR_FAINT = 2,
+	SGR_ITALIC = 3,
+	SGR_UNDERLINE = 4,
+	SGR_BLINK = 5,
+	SGR_BLINK_FAST = 6,
+	SGR_INVERSE = 7,
+	SGR_STRIKE = 9,
+	SGR_FRAKTUR = 20,
+
+	SGR_FG_START = 30,
+	SGR_FG_END = 37,
+	SGR_FG_DEFAULT = 39,
+
+	SGR_BG_START = 40,
+	SGR_BG_END = 47,
+	SGR_BG_DEFAULT = 49,
+
+	SGR_FG_BRT_START = 90,
+	SGR_FG_BRT_END = 97,
+
+	SGR_BG_BRT_START = 100,
+	SGR_BG_BRT_END = 107,
+};
+
+#define SGR_OFF(n) (20+(n))
+
+#endif //ESP_VT100_FIRMWARE_SGR_H