diff --git a/include/controller.h b/include/controller.h
index 87ba72e..48d25b2 100644
--- a/include/controller.h
+++ b/include/controller.h
@@ -24,6 +24,7 @@ private:
 	String _serial_buffer = String();
 	void _execute_serial_command(String cmd);
 	void _execute_command_ls(String path);
+	void _execute_command_ids();
 	void _execute_command_help();
 	unsigned long _button_last_pressed_at[NUM_BUTTONS];
 	bool _check_button(uint8_t btn);
diff --git a/include/player.h b/include/player.h
index a6a9dae..dbefd74 100644
--- a/include/player.h
+++ b/include/player.h
@@ -8,6 +8,7 @@
 
 #define SCI_MODE 0x00
 #define SCI_STATUS 0x01
+#define SCI_BASS 0x02
 #define SCI_CLOCKF 0x03
 #define SCI_DECODE_TIME 0x04
 #define SCI_AUDATA 0x05
@@ -16,6 +17,7 @@
 #define SCI_WRAM 0x06
 #define SCI_HDAT0 0x08
 #define SCI_HDAT1 0x09
+#define SCI_AIADDR 0x0A
 #define SCI_AICTRL0 0x0C
 #define SCI_AICTRL1 0x0D
 #define SCI_AICTRL2 0x0E
@@ -28,14 +30,10 @@
 
 #define SM_RESET 0x0004
 #define SM_CANCEL 0x0008
+#define SM_SDINEW 0x0800
 #define SM_ADPCM 0x1000
 #define SS_DO_NOT_JUMP 0x8000
 
-struct ID_to_Folder_Map {
-	const char* id;
-	const char* folder;
-};
-
 class Player {
 private:
 	enum state { uninitialized, idle, playing, stopping,
@@ -96,8 +94,9 @@ private:
 	uint32_t _skip_to;
 	SPIMaster* _spi;
 	unsigned long _stopped_at;
-	std::list<ID_to_Folder_Map> _id_to_folder_map;
 public:
+	std::map<String, String> id_to_folder_map;
+
 	Player(SPIMaster* s);
 	void vol_up();
 	void vol_down();
diff --git a/src/controller.cpp b/src/controller.cpp
index d156090..ed3e040 100644
--- a/src/controller.cpp
+++ b/src/controller.cpp
@@ -66,7 +66,7 @@ void Controller::_check_rfid() {
 			_no_rfid_card_count = 0;
 			String temp = String(uid, HEX);
 			String s_uid = "";
-			for (int i=0; i<(8-s_uid.length()); i++) {
+			for (int i=0; i<(8-temp.length()); i++) {
 				s_uid.concat("0");
 			}
 			s_uid.concat(temp);
@@ -125,6 +125,8 @@ void Controller::_execute_serial_command(String cmd) {
 		_player->track_prev();
 	} else if (cmd.equals("n")) {
 		_player->track_next();
+	} else if (cmd.equals("ids")) {
+		_execute_command_ids();
 	} else {
 		ERROR("Unknown command: %s\n", cmd.c_str());
 	}
@@ -134,15 +136,22 @@ void Controller::_execute_serial_command(String cmd) {
 void Controller::_execute_command_ls(String path) {
 	INFO("Listing contents of %s:\n", path.c_str());
 	std::list<String> files = _player->ls(path);
-	for(std::list<String>::iterator it=files.begin(); it!=files.end(); it++) {
+	for(std::list<String>::iterator it=files.begin(); it!=files.end(); ++it) {
 		INFO("  %s\n", (*it).c_str());
 	}
 }
 
+void Controller::_execute_command_ids() {
+	for (std::map<String, String>::iterator it = _player->id_to_folder_map.begin(); it!=_player->id_to_folder_map.end(); ++it) {
+		INFO("  %s -> %s\n", it->first.c_str(), it->second.c_str());
+	}
+}
+
 void Controller::_execute_command_help() {
 	INFO("Valid commands are:");
 	INFO("  help      - Displays this help\n");
 	INFO("  ls [dir]  - Lists the contents of [dir] or, if not given, of /\n");
+	INFO("  ids       - Lists all known ID-to-folder mappings\n");
 	INFO("  play [id] - Plays the album with the given id\n");
 	INFO("  sys [file]- Plays the file as system sound\n");
 	INFO("  stop      - Stops playback\n");
diff --git a/src/player.cpp b/src/player.cpp
index ebbaccf..4ab74e2 100644
--- a/src/player.cpp
+++ b/src/player.cpp
@@ -53,15 +53,15 @@ void Player::_init() {
 	DEBUG("VS1053 Init looking good.\n");
 	DEBUG("Upping VS1053 multiplier...\n");
 
-	_write_control_register(SCI_CLOCKF, 0x6000);
+	_write_control_register(SCI_CLOCKF, 0xC000);
 	delay(10);
 
 	_spi_settings = &_spi_settings_fast;
 
 	result = _read_control_register(SCI_CLOCKF);
 	DEBUG("SCI_CLOCKF: 0x%04X\n", result);
-	if (result != 0x6000) {
-		ERROR("Error: SCI_CLOCKF was 0x%04X, expected was 0x6000. Rebooting.\n", result);
+	if (result != 0xC000) {
+		ERROR("Error: SCI_CLOCKF was 0x%04X, expected was 0xC000. Rebooting.\n", result);
 		delay(500);
 		ESP.restart();
 	}
@@ -119,14 +119,16 @@ void Player::_wakeup() {
 
 void Player::_record() {
 	DEBUG("Starting recording.\n");
-	_set_volume(1, false);
-	_write_control_register(SCI_AICTRL0, 8000U); // Sampling rate 8000 Hz
+	set_volume(1, false);
+	_write_control_register(SCI_AICTRL0, 16000); // Sampling rate 8000 Hz
 	_write_control_register(SCI_AICTRL1, 2048U); // Manual gain, 2x
 	_write_control_register(SCI_AICTRL2, 2048U); // Maximum gain for autogain - ignored
-	_write_control_register(SCI_AICTRL3, 6); // 2 (left channel) + 4 (PCM)
-	_write_control_register(SCI_MODE, _read_control_register(SCI_MODE) | SM_ADPCM);
+	_write_control_register(SCI_AICTRL3, 4); // 2 (left channel) + 4 (PCM)
+	_write_control_register(SCI_BASS, 0);
+	_write_control_register(SCI_MODE, SM_ADPCM | SM_SDINEW);
 	DEBUG("SCI_MODE is now 0x%04X\n", _read_control_register(SCI_MODE));
 	_patch_adpcm();
+	_write_control_register(SCI_AIADDR, 0x3000);
 	_state = recording;
 }
 
@@ -189,13 +191,14 @@ void Player::_patch_adpcm() {
 		0x000a,0x0001, /*copy 1*/
 		0x0050,
 	};
-	const uint8_t patch_size = 74;
-	DEBUG("Executing patch_adpcm()...\n");
+	const uint16_t patch_size = 74;
+	DEBUG("Patching...\n");
 
 	_spi->select_vs1053_xcs();
 	SPI.beginTransaction(*_spi_settings);
 	
 	for (int i=0; i<patch_size; i++) {
+		DEBUG("  %d\n", i);
 		unsigned short addr, n, val;
 		addr = patch_data[i++];
 		n = patch_data[i++];
@@ -409,32 +412,34 @@ void Player::_fill_id_to_folder_map() {
 	File entry;
 	while (entry = root.openNextFile()) {
 		String foldername = entry.name();
+		// Remove trailing slash
+		foldername.remove(foldername.length());
 		TRACE("Looking at %s...\n", foldername.c_str());
 		if (!entry.isDirectory() || foldername.startsWith("/.")) continue;
-		if (!SD.exists(foldername + "/id.txt")) {
-			TRACE("Folder %s does not contain id.txt -> ignoring\n", foldername.c_str());
+		if (!SD.exists(foldername + "/ids.txt")) {
+			TRACE("Folder %s does not contain ids.txt -> ignoring\n", foldername.c_str());
 			continue;
 		}
-		TRACE("Reading contents of %s...\n", (foldername + "/id.txt").c_str());
-		File f = SD.open(foldername + "/id.txt");
+		TRACE("Reading contents of %s...\n", (foldername + "/ids.txt").c_str());
+		File f = SD.open(foldername + "/ids.txt");
 		String buffer = "";
 		while (f.available()) {
 			char c = f.read();
 			if (c=='\n' || c=='\r') {
 				if (buffer.length() > 0) {
-					ID_to_Folder_Map m = {buffer.c_str(), foldername.c_str()};
-					DEBUG("Adding mapping '%s'=>'%s'\n", m.id, m.folder);
-					_id_to_folder_map.push_back(m);
+					id_to_folder_map[buffer] = foldername;
+					DEBUG("Adding mapping '%s'=>'%s'\n", buffer.c_str(), foldername.c_str());
 					buffer = "";
 				}
+			} else {
+				buffer.concat(c);
 			}
 		}
 		f.close();
 		
 		if (buffer.length() > 0) {
-			ID_to_Folder_Map m = {buffer.c_str(), foldername.c_str()};
-			DEBUG("Adding mapping '%s'=>'%s'\n", m.id, m.folder);
-			_id_to_folder_map.push_back(m);
+			id_to_folder_map[buffer] = foldername;
+			DEBUG("Adding mapping '%s'=>'%s'\n", buffer.c_str(), foldername.c_str());
 		}
 		entry.close();
 	}
@@ -463,11 +468,10 @@ bool Player::play_id(String id) {
 
 String Player::_foldername_for_id(String id) {
 	DEBUG("Searching for id %s...\n", id.c_str());
-	for(std::list<ID_to_Folder_Map>::iterator it=_id_to_folder_map.begin(); it!=_id_to_folder_map.end(); it++) {
-		if (id.equals((*it).id)) {
-			DEBUG("Found folder '%s' for id %s.\n", (*it).folder, id.c_str());
-			return (*it).folder;
-		}
+	std::map<String, String>::iterator it = id_to_folder_map.find(id);
+	if (it != id_to_folder_map.end()) {
+		DEBUG("Found folder '%s' for id %s.\n", it->first.c_str(), it->second.c_str());
+		return it->second;
 	}
 	DEBUG("No folder found for id %s.\n", id.c_str());
 	return "";