diff -r c850674a3101 -r b3c3d54d2c7c src/display.cpp
--- a/src/display.cpp	Sun Nov 01 22:16:33 2020 +0100
+++ b/src/display.cpp	Sun Nov 01 22:21:19 2020 +0100
@@ -23,26 +23,64 @@
 	set_font((unsigned char*)Terminal6x8);
 	locate(90, 40);
 	this->printf("David Douard");
-	locate(0, 52);
-	this->printf("Clock = %ld ", SystemCoreClock);
+	copy_to_lcd();
+}
 
-	RCC_OscInitTypeDef cfg;
-	HAL_RCC_GetOscConfig(&cfg);
-	if (cfg.HSEState == RCC_HSE_BYPASS)
-		this->printf("HSE:EXT ");
-	else if (cfg.HSEState == RCC_HSE_ON)
-		this->printf("HSE:XTAL ");
-	else
-		this->printf("HSE:OFF ");
-
-	if (cfg.HSIState == RCC_HSI_ON)
-		this->printf("HSI:ON ");
-	else
-		this->printf("HSI:OFF ");
-
+void Display::show_byescreen()
+{
+	cls();
+	background(0x00);
+	foreground(0xFF);
+	locate(30, 10);
+	set_font((unsigned char*)Mono19x27);
+	this->printf("Bye...");
 	copy_to_lcd();
 }
 
+void Display::dimm_char(uint8_t n)
+{
+	// dimm the char number of the currently displayed string of the main area;
+	// do this by printing a modifed version of the last displayed string
+	// but only alphanumeric chars should be counted (not the punctuation)
+	static char txt[64];
+	char c;
+	uint8_t len, i, j;
+	// for which we need to look for the entry in the table
+	for (i=0; i<sizeof(table)/sizeof(table[0]); ++i) {
+		if (table[i].cmd == 0x00) {
+			::printf("DIMM CHAR %d\n", n);
+			::printf("repl  '%s'\n", table[i].buffer);
+			len = strlen(table[i].buffer);
+			if (n >= len)
+				break;  // nothing to do
+			strncpy(txt, table[i].buffer, table[i].maxsize);
+			// look for the actual position of the char in the string (only alphanum)
+			// XXX very poor implementation...
+			for (j=0; (j<len)&&(j<=n); j++)
+			{
+				c = txt[j];
+				if ((c == ',') || (c == '.') || (c == ';') || (c == ':') || (c == ' '))
+					n++;
+			}
+			// now move the end of the string for char n to steps on the right
+			// so we can insert our 2 '\t' characters before and after the
+			// character to dimm
+			for (j=len; j>n; j--)
+			{
+				txt[j+2] = txt[j];
+			}
+			txt[n+2] = '\t';
+			txt[n+1] = txt[n];
+			txt[n] = '\t';
+			txt[len+2] = 0x00; // make sure the string will be terminated
+
+			::printf("with  '%s'\n", txt);
+			// now display this string
+			show(0x00, txt, 0);
+			break;
+		}
+	}
+}
 
 void Display::show(uint8_t cmd, const char *intxt, uint8_t nchar=0)
 {
@@ -52,21 +90,24 @@
 	char *oldv;
 	// char *txt;
 	char *txtp;
-	static char txt[256];
+	static char txt[64];
 
 
 	if (cmd == 0xFF) // cls
 	{
 		clrbuff();
 	}
+	else if (cmd == 0x0D)
+	{ // dimm a character of the main area
+		dimm_char(intxt[0]);
+	}
 	else
 	{
-		//txt = (char *)malloc(strlen(intxt)+1);
-		strcpy(txt, intxt);
-		txtp = txt;
-
 		for (i=0; i<sizeof(table)/sizeof(table[0]); ++i) {
 			if (table[i].cmd == cmd) {
+				strcpy(txt, intxt);
+				txtp = txt;
+
 				bgcolor = table[i].bgcolor;
 				fgcolor = table[i].color;
 				background(bgcolor);
@@ -76,45 +117,48 @@
 
 				locate(table[i].x0, table[i].y0);
 
-				if (table[i].fmt & 0x01)  // ASCII text
+				if (table[i].fmt & FMT_ASCII)  // ASCII text
 				{
+					// check if the string has changed since last time
 					if (strncmp(oldv, txt, table[i].maxsize) != 0)
 					{
+						// clear the text area
 						if (table[i].width > 0)
 							fillrect(table[i].x0,
-														table[i].y0,
-														table[i].x0 + table[i].width,
-														table[i].y0 + table[i].font[2],
-														bgcolor);
+									 table[i].y0,
+									 table[i].x0 + table[i].width,
+									 table[i].y0 + table[i].font[2] - 1,
+									 bgcolor);
+						// draw chars by portions of string separated by \t (highlight)
 						for (uint8_t k=0; ;k++)
 						{
 							if (txtp[k] == 0x00)
-							{
+							{ // end of string, display it
 								this->printf(txtp);
 								break;
 							}
 							if (txtp[k] == 0x09)
 							{ // \t is a special char for 'unselected' display value
+								// first disply the beginning of the string
 								txtp[k] = 0x00;
 								this->printf(txtp);
 
+								// swap the fg color (dimm/bright)
 								if (fgcolor == table[i].color)
 									fgcolor /= 2;
 								else
 									fgcolor = table[i].color;
 								foreground(fgcolor);
+								// continue on the next with part of the string
 								txtp = &(txtp[k+1]);
 								k = 0;
 							}
 						}
-						if (cmd == 0x00) // main area
-							must_refresh |= 0x01;
-						if (cmd == 0x0C) // channels area
-							must_refresh |= 0x04;
+						must_refresh = 1;
 					}
 				}
 				/*
-					if (table[i].fmt & 0x02 ) {
+					if (table[i].fmt & FMT_HEX ) {
 					// hex
 					for (uint8_t j=0;; j++) {
 					if (txt[j] == 0x00)
@@ -125,52 +169,42 @@
 					this->printf(" ");
 					}
 				*/
-				if (table[i].fmt & 0x08 )  // flag indicators
+				if (table[i].fmt & FMT_FLAGS )  // flag indicators
 				{
+					uint8_t nbyte;
+					uint8_t nbit;
 					// flags
-					for (uint8_t j=0; j<max(nchar, table[i].maxsize) ; j++)
+					for (uint8_t l=0; l<(sizeof(flags)/sizeof(flags[0])); ++l)
 					{
-						for (uint8_t k=0; k<8; k++)
-						{
-							if (1)
-							{ //(txt[j] & (1 << k) ) != (oldv[j] & (1 << k))) {
-								for (uint8_t l=0;
-										 l<(sizeof(flags)/sizeof(flags[0])); ++l)
-								{
-									if (flags[l].flag == ((j<<4) + k)) {
-										if (txtp[j] & (1 << k))
-										{
-											foreground(flags[l].reverse ? bgcolor : fgcolor);
-											background(flags[l].reverse ? fgcolor : bgcolor);
-										}
-										else
-										{
-											foreground(bgcolor);
-											background(bgcolor);
-										}
-										if (flags[l].msg != NULL)
-										{ // a string
-											locate(flags[l].x, flags[l].y);
-											this->printf(flags[l].msg);}
-										else
-										{ // an icon
-											Bitmap_s pic = {9, 10, 2, (char*) flags[l].icon};
-											Bitmap_BW(pic, flags[l].x, flags[l].y);
-										}
-										must_refresh = 1; //|= zones[m].flag;
-										break;
-									}
-								}
-							}
+						nbyte = flags[l].flag / 8;
+						nbit = flags[l].flag % 8;
+
+						if (intxt[nbyte] & (1 << nbit))
+						{  // draw the flag, possibly reversed fg/bg
+							foreground(flags[l].reverse ? bgcolor : fgcolor);
+							background(flags[l].reverse ? fgcolor : bgcolor);
+						}
+						else
+						{  // erase the flag
+							foreground(bgcolor);
+							background(bgcolor);
+						}
+						if (flags[l].msg != NULL)
+						{ // flag is a string
+							locate(flags[l].x, flags[l].y);
+							this->printf(flags[l].msg);}
+						else
+						{ // flag is an icon
+							Bitmap_s pic = {9, 10, 2, (char*) flags[l].icon};
+							Bitmap_BW(pic, flags[l].x, flags[l].y);
 						}
 					}
 
 					// draw frames (Alarm and Channel)
-					for (uint8_t l=0;
-							 l<(sizeof(frames)/sizeof(frames[0])); ++l)
+					for (uint8_t l=0; l<(sizeof(frames)/sizeof(frames[0])); ++l)
 					{
 						uint16_t color;
-						if (frames[l].flag & txt[0]) // frame flags are on the 1st byte only
+						if (intxt[0] & (1 << frames[l].flag)) // frame flags are on the 1st byte only
 							color = fgcolor/6;
 						else
 							color = bgcolor;
@@ -181,6 +215,7 @@
 						vline(frames[l].x0, frames[l].y0+1, frames[l].y1-1, color);
 						vline(frames[l].x1, frames[l].y0+1, frames[l].y1-1, color);
 					}
+					must_refresh = 1; //|= zones[m].flag;
 				}
 
 				for(uint8_t j=0; j<table[i].maxsize; j++)
@@ -194,6 +229,61 @@
 }
 
 
+void Display::set_flag(uint8_t flag, bool show=true)
+{
+	uint8_t i;
+	uint8_t bgcolor = 0x00, fgcolor = 0xFF;
+
+	for (uint8_t l=0; l<(sizeof(flags)/sizeof(flags[0])); ++l)
+	{
+		if (flag == flags[l].flag)
+		{
+
+			if (show)
+			{
+				foreground(flags[l].reverse ? bgcolor : fgcolor);
+				background(flags[l].reverse ? fgcolor : bgcolor);
+			}
+			else
+			{
+				foreground(bgcolor);
+				background(bgcolor);
+			}
+			if (flags[l].msg != NULL)
+			{ // flag is a string
+				locate(flags[l].x, flags[l].y);
+				set_font((unsigned char*)Terminal6x8);
+				this->printf(flags[l].msg);}
+			else
+			{ // flag is an icon
+				Bitmap_s pic = {9, 10, 2, (char*) flags[l].icon};
+				Bitmap_BW(pic, flags[l].x, flags[l].y);
+			}
+		}
+	}
+
+	// draw frames (Alarm and Channel)
+	for (uint8_t l=0; l<(sizeof(frames)/sizeof(frames[0])); ++l)
+	{
+		if (flag == frames[l].flag)
+		{
+			uint16_t color;
+			if (show)
+				color = fgcolor/6;
+			else
+				color = bgcolor;
+			hline(frames[l].x0+1, frames[l].x0+3, frames[l].y0, color);
+			hline(frames[l].x1-3, frames[l].x1-1, frames[l].y0, color);
+			hline(frames[l].x0+1, frames[l].x1-1, frames[l].y1, color);
+
+			vline(frames[l].x0, frames[l].y0+1, frames[l].y1-1, color);
+			vline(frames[l].x1, frames[l].y0+1, frames[l].y1-1, color);
+		}
+	}
+	must_refresh = 1;
+}
+
+
 void Display::test_dsp()
 {
 	const FRAME *z;