diff --git a/sw/pc/sc64.py b/sw/pc/sc64.py
index 7567550..1261e37 100644
--- a/sw/pc/sc64.py
+++ b/sw/pc/sc64.py
@@ -46,12 +46,12 @@ class SC64:
     __DDIPL_ROM_LENGTH = 0x400000
 
     __DEBUG_ID_TEXT = 0x01
-    __DEBUG_ID_EVENT = 0xFE
-
-    __EVENT_ID_FSD_READ = 0
-    __EVENT_ID_FSD_WRITE = 1
-    __EVENT_ID_DD_BLOCK = 2
-    __EVENT_ID_IS_VIEWER = 3
+    __EVENT_ID_FSD_READ = 0xF0
+    __EVENT_ID_FSD_WRITE = 0xF1
+    __EVENT_ID_FSD_LOAD = 0xF2
+    __EVENT_ID_FSD_STORE = 0xF3
+    __EVENT_ID_DD_BLOCK = 0xF4
+    __EVENT_ID_IS_VIEWER = 0xF5
 
     __DD_DRIVE_ID_RETAIL = 3
     __DD_DRIVE_ID_DEVELOPMENT = 4
@@ -599,20 +599,6 @@ class SC64:
             pass
 
 
-    def __debug_process_event(self, event_data: bytes) -> None:
-        id = int.from_bytes(event_data[0:4], byteorder="big")
-        data = event_data[4:]
-
-        if (id == self.__EVENT_ID_FSD_READ):
-            self.__debug_process_fsd_read(data)
-        elif (id == self.__EVENT_ID_FSD_WRITE):
-            self.__debug_process_fsd_write(data)
-        elif (id == self.__EVENT_ID_DD_BLOCK):
-            self.__debug_process_dd_block(data)
-        elif (id == self.__EVENT_ID_IS_VIEWER):
-            self.__debug_process_is_viewer(data)
-
-
     def debug_init(self, fsd_file: str = None, disk_file: str = None, dd_turbo: bool = False) -> None:
         if (fsd_file):
             self.__fsd_file = open(fsd_file, "rb+")
@@ -654,8 +640,14 @@ class SC64:
             else:
                 if (id == self.__DEBUG_ID_TEXT):
                     print(data.decode(encoding="ascii", errors="backslashreplace"), end="")
-                elif (id == self.__DEBUG_ID_EVENT):
-                    self.__debug_process_event(data)
+                elif (id == self.__EVENT_ID_FSD_READ):
+                    self.__debug_process_fsd_read(data)
+                elif (id == self.__EVENT_ID_FSD_WRITE):
+                    self.__debug_process_fsd_write(data)
+                elif (id == self.__EVENT_ID_DD_BLOCK):
+                    self.__debug_process_dd_block(data)
+                elif (id == self.__EVENT_ID_IS_VIEWER):
+                    self.__debug_process_is_viewer(data)
                 else:
                     print(f"\033[35mGot unknown id: {id}, length: {length}\033[0m", file=sys.stderr)
 
diff --git a/sw/riscv/src/usb.c b/sw/riscv/src/usb.c
index ae0add6..fbff580 100644
--- a/sw/riscv/src/usb.c
+++ b/sw/riscv/src/usb.c
@@ -66,8 +66,6 @@ static bool tx_word (uint32_t data) {
 #define USB_DMA_TOKEN       (0x444D4100)
 #define USB_ERR_TOKEN       (0x45525200)
 
-#define DEBUG_ID_EVENT      (0xFE)
-
 
 enum state {
     STATE_IDLE,
@@ -84,7 +82,6 @@ struct process {
     uint32_t args[2];
     bool error;
     bool dma_in_progress;
-    bool queried;
 
     bool event_pending;
     bool event_callback_pending;
@@ -183,7 +180,6 @@ void process_usb (void) {
                     p.counter = 0;
                     p.error = false;
                     p.dma_in_progress = false;
-                    p.queried = false;
                     p.state = STATE_ARGS;
                 } else {
                     p.cmd = '!';
@@ -220,9 +216,9 @@ void process_usb (void) {
                     break;
 
                 case 'Q':
-                    if (!p.queried) {
+                    if (p.counter == 0) {
                         cfg_query(p.args);
-                        p.queried = true;
+                        p.counter += 1;
                     }
                     if (tx_word(p.args[1])) {
                         p.state = STATE_RESPONSE;
@@ -317,18 +313,15 @@ void process_usb (void) {
             if ((p.counter == 0) && tx_word(USB_DMA_TOKEN | '@')) {
                 p.counter += 1;
             }
-            if ((p.counter == 1) && tx_word((DEBUG_ID_EVENT << 24) | (sizeof(p.event.id) + p.event_data_length))) {
+            if ((p.counter == 1) && tx_word(((p.event.id & 0xFF) << 24) | p.event_data_length)) {
                 p.counter += 1;
             }
-            if ((p.counter == 2) && tx_word(p.event.id)) {
-                p.counter += 1;
-            }
-            if (p.counter >= 3) {
-                while (((p.counter - 3) < p.event_data_length) && tx_byte(p.event_data[p.counter - 3])) {
+            if (p.counter >= 2) {
+                while (((p.counter - 2) < p.event_data_length) && tx_byte(p.event_data[p.counter - 2])) {
                     p.counter += 1;
                 }
             }
-            if ((p.counter == (p.event_data_length + 3)) && tx_word(USB_CMP_TOKEN | 'H')) {
+            if ((p.counter == (p.event_data_length + 2)) && tx_word(USB_CMP_TOKEN | 'H')) {
                 if (p.event.callback != NULL) {
                     p.event_callback_pending = true;
                 }
diff --git a/sw/riscv/src/usb.h b/sw/riscv/src/usb.h
index 5402f37..efac87d 100644
--- a/sw/riscv/src/usb.h
+++ b/sw/riscv/src/usb.h
@@ -6,17 +6,12 @@
 
 
 typedef enum {
-    INT_DBG_ID_IS_VIEWER = 0,
-    INT_DBG_ID_DD_BLOCK = 1,
-    INT_DBG_ID_FSD_READ = 2,
-    INT_DBG_ID_FSD_WRITE = 3,
-} internal_debug_id_t;
-
-typedef enum {
-    EVENT_ID_FSD_READ = 0,
-    EVENT_ID_FSD_WRITE = 1,
-    EVENT_ID_DD_BLOCK = 2,
-    EVENT_ID_IS_VIEWER = 3,
+    EVENT_ID_FSD_READ = 0xF0,
+    EVENT_ID_FSD_WRITE = 0xF1,
+    EVENT_ID_FSD_LOAD = 0xF2,
+    EVENT_ID_FSD_STORE = 0xF3,
+    EVENT_ID_DD_BLOCK = 0xF4,
+    EVENT_ID_IS_VIEWER = 0xF5,
 } usb_event_id_t;
 
 typedef enum {