diff --git a/src/computer.c b/src/computer.c
index d38f33f..22260c4 100644
--- a/src/computer.c
+++ b/src/computer.c
@@ -1713,7 +1713,7 @@ void ResetComputer () {
 	
 	ordenador.last_selected_poke_file[0]='\0';
 	
-	ordenador.tst_sample=(ordenador.cpufreq + ordenador.freq/2)/ordenador.freq;
+	ordenador.tst_sample=(ordenador.cpufreq + (ordenador.freq*N_SAMPLES/2))/(ordenador.freq*N_SAMPLES);
 	
 	microdrive_reset();
 	
diff --git a/src/computer.h b/src/computer.h
index 3edd481..223561f 100644
--- a/src/computer.h
+++ b/src/computer.h
@@ -28,6 +28,7 @@
 
 #define KB_BUFFER_LENGHT 10
 #define MAX_PATH_LENGTH 256
+#define N_SAMPLES 4
 
 extern char salir;
 
diff --git a/src/emulator.c b/src/emulator.c
index 42e1210..5d39a91 100644
--- a/src/emulator.c
+++ b/src/emulator.c
@@ -584,7 +584,7 @@ int bucle, bucle2,ret2;
 	}
 
 	printf("Init sound 2\n");
-	ordenador.tst_sample=(ordenador.cpufreq + ordenador.freq/2)/ordenador.freq;
+	ordenador.tst_sample=(ordenador.cpufreq + (ordenador.freq*N_SAMPLES/2))/(ordenador.freq*N_SAMPLES);
 }
 
 void end_system() {
diff --git a/src/menu_sdl.c b/src/menu_sdl.c
index 8c1effa..2cbc20d 100644
--- a/src/menu_sdl.c
+++ b/src/menu_sdl.c
@@ -344,7 +344,6 @@ static const char **get_file_list(const char *base_dir)
 	int cur = 0;
 	struct dirent *de;
 	int cnt = 16;
-	int i;
 
 	if (!d)
 		return NULL;
@@ -371,6 +370,7 @@ static const char **get_file_list(const char *base_dir)
 			size_t len = strlen(de->d_name) + 4;
 
 			p = (char*)malloc( len );
+			if (p==NULL) break; //Terminate the list
 			snprintf(p, len, "[%s]", de->d_name);
 			file_list[cur++] = p;
 			file_list[cur] = NULL;
@@ -380,6 +380,7 @@ static const char **get_file_list(const char *base_dir)
 			char *p;
 
 			p = strdup(de->d_name);
+			if (p==NULL) break; //Terminate the list
 			file_list[cur++] = p;
 			file_list[cur] = NULL;
 		}
@@ -388,15 +389,8 @@ static const char **get_file_list(const char *base_dir)
 		{
 			cnt = cnt + 32;
 			realloc_file_list = (const char**)realloc(file_list, cnt * sizeof(char*));
-			if (realloc_file_list) file_list = realloc_file_list; else
-				{
-				/* Cleanup everything - file_list is NULL-terminated */
-				for ( i = 0; file_list[i]; i++ )
-				free((void*)file_list[i]);
-				free(file_list);
-				closedir(d);
-				return NULL;
-				}
+			if (realloc_file_list) file_list = realloc_file_list; else break;
+				
 		}
 	}
 	closedir(d);
diff --git a/src/menus.c b/src/menus.c
index 9100bd0..6df076d 100644
--- a/src/menus.c
+++ b/src/menus.c
@@ -1747,7 +1747,7 @@ char *select_file(char *path,enum LOAD_FILE_TYPES kind) {
 	unsigned char fin,read,*salida;
 	int bucle,ancho,numitems,selected,from,longitud;
 
-	salida=(unsigned char *)malloc(2049);
+	salida=(unsigned char *)malloc(MAX_PATH_LENGTH);
 	salida[0]=0;
 
 	ancho=screen->w;
@@ -2018,6 +2018,6 @@ if (freq == 0)
 	}
 else ordenador.cpufreq = freq;
 
-ordenador.tst_sample=(ordenador.cpufreq + ordenador.freq/2)/ordenador.freq;
+ordenador.tst_sample=(ordenador.cpufreq + (ordenador.freq*N_SAMPLES/2))/(ordenador.freq*N_SAMPLES);
 
 }
\ No newline at end of file
diff --git a/src/spk_ay.c b/src/spk_ay.c
index 5eab8fc..32710a7 100644
--- a/src/spk_ay.c
+++ b/src/spk_ay.c
@@ -24,7 +24,8 @@
 #include "sound.h"
 #include <stdlib.h>
 
-unsigned int beeper = 0;
+unsigned int beeper = 0, lvalue_sum=0, rvalue_sum=0 ;
+unsigned char sample_count = 0;
 
 /* emulates the AY-3-8912 during TSTADOS tstates */
 
@@ -314,23 +315,12 @@ inline void play_ay (unsigned int tstados) {
 
 inline void play_sound (unsigned int tstados) {
 
-	int lvalue, rvalue;
-
 	ordenador.tstados_counter_sound += tstados;
 
 	while (ordenador.tstados_counter_sound >= ordenador.tst_sample)	{
 
 		ordenador.tstados_counter_sound -= ordenador.tst_sample;
 		
-		/*
-		//Low pass filter
-		if (ordenador.sound_bit)
-		{
-			if (beeper<480) beeper = beeper + ordenador.low_filter; //Sound bit volume max 480*vol	
-		}			
-		else if (beeper>0) beeper = beeper - ordenador.low_filter;
-		*/
-		
 		if (ordenador.sound_bit)
 		{
 			if (ordenador.sound_bit_mic) beeper = 544; //480 + 64 - MIC is audible only if EAR is on
@@ -340,46 +330,55 @@ inline void play_sound (unsigned int tstados) {
 
 		//Each channel max 256*vol
 		
-		if (ordenador.ay_emul)
+		if ((ordenador.ay_emul)&&(!ordenador.turbo_state))
 		{
 			switch (ordenador.audio_mode)
 			{
 				case 0: //Mono
-				lvalue = (beeper + ordenador.vol_a  + ordenador.vol_b +ordenador.vol_c)*ordenador.volume;	
-				rvalue = (beeper + ordenador.vol_a  + ordenador.vol_b +ordenador.vol_c)*ordenador.volume;
+				lvalue_sum = lvalue_sum + (beeper + ordenador.vol_a  + ordenador.vol_b +ordenador.vol_c)*ordenador.volume;	
+				rvalue_sum = rvalue_sum + (beeper + ordenador.vol_a  + ordenador.vol_b +ordenador.vol_c)*ordenador.volume;
 				break;
 				case 1: //ABC
-				lvalue = (beeper + ordenador.vol_a*2  + ordenador.vol_b)*ordenador.volume;	
-				rvalue = (beeper + ordenador.vol_b + ordenador.vol_c*2)*ordenador.volume;
+				lvalue_sum = lvalue_sum + (beeper + ordenador.vol_a*2  + ordenador.vol_b)*ordenador.volume;	
+				rvalue_sum = rvalue_sum + (beeper + ordenador.vol_b + ordenador.vol_c*2)*ordenador.volume;
 				break;
 				case 2: //ACB
-				lvalue = (beeper + ordenador.vol_a*2  + ordenador.vol_c)*ordenador.volume;	
-				rvalue = (beeper + ordenador.vol_c + ordenador.vol_b*2)*ordenador.volume;
+				lvalue_sum = lvalue_sum + (beeper + ordenador.vol_a*2  + ordenador.vol_c)*ordenador.volume;	
+				rvalue_sum = rvalue_sum + (beeper + ordenador.vol_c + ordenador.vol_b*2)*ordenador.volume;
 				break;
 				case 3: //BAC
-				lvalue = (beeper + ordenador.vol_b*2  + ordenador.vol_a)*ordenador.volume;	
-				rvalue = (beeper + ordenador.vol_a + ordenador.vol_c*2)*ordenador.volume;
+				lvalue_sum = lvalue_sum + (beeper + ordenador.vol_b*2  + ordenador.vol_a)*ordenador.volume;	
+				rvalue_sum = rvalue_sum + (beeper + ordenador.vol_a + ordenador.vol_c*2)*ordenador.volume;
 				break;
 				default: //No emulation
-				rvalue = beeper*ordenador.volume;
-				lvalue = beeper*ordenador.volume;
+				lvalue_sum = lvalue_sum + beeper*ordenador.volume;
+				rvalue_sum = rvalue_sum + beeper*ordenador.volume;
 				break;
 			}
 		}
 		else
 		{
-			rvalue = beeper*ordenador.volume;
-			lvalue = beeper*ordenador.volume;
+			lvalue_sum = lvalue_sum + beeper*ordenador.volume;
+			rvalue_sum = rvalue_sum + beeper*ordenador.volume;
 		}
+	
 		
-		*ordenador.current_buffer =	(rvalue<<16)|(lvalue);
-		ordenador.current_buffer++;
+		if (sample_count==(N_SAMPLES-1))
+		{
 		
-		ordenador.sound_cuantity++;
+			*ordenador.current_buffer =	((rvalue_sum/N_SAMPLES)<<16)|(lvalue_sum/N_SAMPLES);
+			ordenador.current_buffer++;
+		
+			ordenador.sound_cuantity++;
 
-		if (ordenador.sound_cuantity == ordenador.buffer_len) {		// buffer filled
-			sound_play();
-			ordenador.sound_cuantity = 0;
+			if (ordenador.sound_cuantity == ordenador.buffer_len) {		// buffer filled
+				sound_play();
+				ordenador.sound_cuantity = 0;
+			}
+		sample_count=0;
+		lvalue_sum=0;
+		rvalue_sum=0;
 		}
+		else sample_count++;
 	}
 }
diff --git a/src/tape.c b/src/tape.c
index 61e11ab..5cfe05c 100644
--- a/src/tape.c
+++ b/src/tape.c
@@ -57,8 +57,8 @@ inline void tape_read(FILE *fichero, int tstados) {
 	//Auto ultra fast mode
 	if ((ordenador.turbo_state != 1)&&(ordenador.turbo==1))
 	{
-		if (ordenador.tape_file_type==TAP_TAP) update_frequency(13000000);
-		else update_frequency(11000000);
+		if (ordenador.tape_file_type==TAP_TAP) update_frequency(12500000);
+		else update_frequency(10500000);
 		jump_frames=7;
 		ordenador.precision_old=ordenador.precision;
 		ordenador.precision =0;
@@ -207,6 +207,7 @@ inline void tape_read_tzx (FILE * fichero, int tstados) {
 	static unsigned char value, value2,value3,value4,done;
 	static unsigned int bucle,bucle2, byte_position;
 	int retval;
+	char block_jump[2];
 	
 	if (fichero == NULL)
 		{
@@ -423,6 +424,11 @@ inline void tape_read_tzx (FILE * fichero, int tstados) {
 					
 				case 0x22: // group end
 					break;
+					
+				case 0x23: // jump to block
+					retval=fread(block_jump,1,2,fichero);
+					jump_to_block(fichero, (int) block_jump[0] + 256*((int) block_jump[1]));
+				break;
 				
 				case 0x24: // loop start
 					retval=fread(&value2,1,1,fichero);
@@ -938,6 +944,7 @@ void fastload_block_tzx (FILE * fichero) {
 	unsigned int longitud, len, bucle, number_bytes, byte_position, byte_position2, retorno;
 	unsigned char value[65536], empty, blockid, parity, pause[2],flag_byte;	
 	int retval;
+	char block_jump[2];
 	
 	longitud =0;
 	pause[0]=pause[1]=0;
@@ -1039,11 +1046,19 @@ void fastload_block_tzx (FILE * fichero) {
 				break;
 					
 				case 0x21: // group start
-					retorno=2;	
+					retval=fread(value,1,1,fichero);
+					if (retval!=1) {procesador.Rm.br.F &= (~F_C);return;} 
+					len = (unsigned int) value[0];
+					retval=fread(value,1,len,fichero);	
 				break;
 					
 				case 0x22: // group end
-					retorno=2;
+				break;
+				
+				case 0x23: // jump to block
+					retval=fread(block_jump,1,2,fichero);
+					if (retval!=2) {procesador.Rm.br.F &= (~F_C);return;} 
+					jump_to_block(fichero, (int) block_jump[0] + 256*((int) block_jump[1]));
 				break;
 				
 				case 0x24: // loop start
diff --git a/src/tape_browser.c b/src/tape_browser.c
index a4fdf9f..48e00b3 100644
--- a/src/tape_browser.c
+++ b/src/tape_browser.c
@@ -40,7 +40,8 @@ struct tape_select *block_select_list[MAX_SELECT_ITEM+1];
 void browser_tzx (FILE * fichero) {
 
 	unsigned int longitud, len, bucle, byte_position, retorno, block_number;
-	unsigned char value[65536], empty, blockid, pause[2], flag_byte;	
+	unsigned char value[65536], empty, blockid, pause[2], flag_byte;
+	char block_jump[2];
 	int retval, retval2;
 	
 	longitud =0;
@@ -196,7 +197,7 @@ void browser_tzx (FILE * fichero) {
 					if (longitud==0) strcpy(browser_list[block_number]->block_type,"Stop the Tape      ");
 					else
 						{ 
-						strcpy(browser_list[block_number]->block_type,"Pause:             ");
+						strcpy(browser_list[block_number]->block_type,"Pause              ");
 						sprintf(browser_list[block_number]->info,"%d ms", longitud);
 						}
 				break;
@@ -216,6 +217,13 @@ void browser_tzx (FILE * fichero) {
 					strcpy(browser_list[block_number]->block_type,"Group end          ");
 				break;
 				
+				case 0x23: // jump to block
+					strcpy(browser_list[block_number]->block_type,"Jump to block      ");
+					retval=fread(block_jump,1,2,fichero);
+					if (retval!=2) {retorno=1;break;}
+					sprintf(browser_list[block_number]->info,"Block: %d", ((int) block_jump[0]) + 256*((int) block_jump[1]) + ((int) block_number));
+				break;
+
 				case 0x24: // loop start
 					strcpy(browser_list[block_number]->block_type,"Loop start         ");
 					retval=fread(value,1,2, fichero);
@@ -302,7 +310,7 @@ void browser_tzx (FILE * fichero) {
 					
 				default: // not supported
 					strcpy(browser_list[block_number]->block_type,"Not supported");
-					retorno=1; //Tape error				
+					retorno=1; //Error				
 				break;
 			}
 			block_number++;
@@ -421,7 +429,7 @@ browser_list[block_number]=NULL;
 
 int select_block(FILE * fichero)
 {
-	unsigned int longitud, bucle, byte_position, block_number,nblocks,offset, blk_sel_pos;
+	unsigned int longitud, bucle, block_number,nblocks,offset, blk_sel_pos;
 	unsigned char value[64], len_text;	
 	int retval;
 	
@@ -434,14 +442,14 @@ int select_block(FILE * fichero)
 		block_select_list[bucle]=NULL;
 	}
 	
-	byte_position=ftell(fichero)-1;
-	
-	//search for select block
+	//search for select block position
 	for(blk_sel_pos=0; 
-	((browser_list[blk_sel_pos]!=NULL)&&(blk_sel_pos<MAX_BROWSER_ITEM)&&(browser_list[blk_sel_pos]->position!=byte_position)); 
+	((blk_sel_pos<MAX_BROWSER_ITEM)&&(browser_list[blk_sel_pos]!=NULL)&&(browser_list[blk_sel_pos]->position!=ordenador.tape_position)); 
 	blk_sel_pos++);
 	
-	if (browser_list[blk_sel_pos]->position!=byte_position) return -1;
+	if (browser_list[blk_sel_pos]==NULL) return -1;
+	
+	if (browser_list[blk_sel_pos]->position!=ordenador.tape_position) return -1;
 	
 	retval=fread(value,1,3,fichero);
 	if (retval!=3) {return -1;} 
@@ -473,7 +481,7 @@ int select_block(FILE * fichero)
 	block_select_list[block_number]=NULL;	
 	if (feof(fichero)) return -1;
 	
-	unsigned int tape_position, block_n_int;
+	unsigned int block_n_int;
 	const char *row_selected; 
 	char block_n[3];
 	
@@ -488,23 +496,52 @@ int select_block(FILE * fichero)
 	
 	block_n_int=atoi(block_n);
 	
-	if ((block_n_int<0)||(block_n_int >(MAX_SELECT_ITEM-1))) return -1;
+	if ((block_n_int<0)||(block_n_int >(MAX_SELECT_ITEM-1))||block_select_list[block_n_int]==NULL) return -1;
 	
 	if ((block_select_list[block_n_int]->offset+blk_sel_pos) > (MAX_BROWSER_ITEM-1)) return -1;
 	
-	tape_position=browser_list[block_select_list[block_n_int]->offset+blk_sel_pos]->position;
+	if (browser_list[block_select_list[block_n_int]->offset+blk_sel_pos]==NULL) return -1;
+	
+	ordenador.tape_position=browser_list[block_select_list[block_n_int]->offset+blk_sel_pos]->position;
  
 	ordenador.tape_current_bit=0;
 	ordenador.tape_current_mode=TAP_TRASH;
 	ordenador.next_block= NOBLOCK;
 	
-	fseek(ordenador.tap_file, tape_position, SEEK_SET);
-	ordenador.tape_position = tape_position;
+	fseek(ordenador.tap_file, ordenador.tape_position, SEEK_SET);
 	free((void*)row_selected);
 	
 	return 0;
 }
 
+int jump_to_block(FILE * fichero, int blocks_to_jump)
+{
+
+	int blk_sel_pos, dest_block;
+
+	
+	//search for block position
+	for(blk_sel_pos=0; 
+	((blk_sel_pos<MAX_BROWSER_ITEM)&&(browser_list[blk_sel_pos]!=NULL)&&(browser_list[blk_sel_pos]->position!=ordenador.tape_position)); 
+	blk_sel_pos++);
+	
+	if (browser_list[blk_sel_pos]==NULL) return -1;
+	
+	if (browser_list[blk_sel_pos]->position!=ordenador.tape_position) return -1;
+	
+	dest_block=blk_sel_pos+blocks_to_jump;
+	
+	if ((dest_block<0)||(dest_block>MAX_BROWSER_ITEM)) return -1;
+	
+	if (browser_list[dest_block]==NULL) return -1;
+	
+	fseek(fichero, browser_list[dest_block]->position, SEEK_SET);
+	
+	ordenador.tape_position = browser_list[dest_block]->position;
+
+	return 0;
+}
+
 void free_browser()
 {
 	unsigned int bucle; 
diff --git a/src/tape_browser.h b/src/tape_browser.h
index 06e2ca7..63123c7 100644
--- a/src/tape_browser.h
+++ b/src/tape_browser.h
@@ -40,6 +40,7 @@ extern struct browser *browser_list[MAX_BROWSER_ITEM+1];
 void browser_tap (FILE *);
 void browser_tzx (FILE *);
 int select_block(FILE * fichero);
+int jump_to_block(FILE * fichero, int blocks_to_jump);
 void free_browser();
 
 #endif