diff --git a/data/eng/settings/autorun.dat b/data/eng/settings/autorun.dat
index d1c5fed495..9f92fbb837 100644
--- a/data/eng/settings/autorun.dat
+++ b/data/eng/settings/autorun.dat
@@ -4,7 +4,7 @@
 # If delay is negative, wait for termination of the spawned process. Otherwise, simply wait
 #
 #/SYS/CROPFLAT "XS800 YS480"	   1	# set limits of screen
-#/SYS/LOADDRV  "COM_MOUSE"	   1	# serial mouse driver
+#/SYS/LOADDRV  "COMMOUSE"	   1	# serial mouse driver
 #/SYS/DEVELOP/BOARD   ""	   1	# Load DEBUG board
 #/SYS/refrscrn	      ""	   1	# Refresh screen
 /SYS/LOADDRV         "RDC"        1    # videodriver for RDC M2010/M2012
diff --git a/data/et/settings/autorun.dat b/data/et/settings/autorun.dat
index 5f8f84a7e4..e9351cb42c 100644
--- a/data/et/settings/autorun.dat
+++ b/data/et/settings/autorun.dat
@@ -4,7 +4,7 @@
 # If delay is negative, wait for termination of the spawned process. Otherwise, simply wait
 #
 #/SYS/CROPFLAT "XS800 YS480"	   1	# set limits of screen
-#/SYS/LOADDRV		"COM_MOUSE"	   1	# serial mouse driver
+#/SYS/LOADDRV		"COMMOUSE"	   1	# serial mouse driver
 #/SYS/DEVELOP/BOARD   ""	   1	# Load DEBUG board
 #/SYS/refrscrn	      ""	   1	# Refresh screen
 /SYS/LOADDRV         "RDC"        1    # videodriver for RDC M2010/M2012
diff --git a/data/it/settings/autorun.dat b/data/it/settings/autorun.dat
index 70705dfce2..3610eb96f1 100644
--- a/data/it/settings/autorun.dat
+++ b/data/it/settings/autorun.dat
@@ -4,7 +4,7 @@
 # If delay is negative, wait for termination of the spawned process. Otherwise, simply wait
 #
 #/SYS/CROPFLAT "XS800 YS480"	   1	# set limits of screen
-#/SYS/LOADDRV	  "COM_MOUSE"	   1	# serial mouse driver
+#/SYS/LOADDRV	  "COMMOUSE"	   1	# serial mouse driver
 #/SYS/DEVELOP/BOARD   ""	   1	# Load DEBUG board
 #/SYS/refrscrn	      ""	   1	# Refresh screen
 /SYS/LOADDRV         "RDC"        1    # videodriver for RDC M2010/M2012
diff --git a/data/rus/settings/autorun.dat b/data/rus/settings/autorun.dat
index 70705dfce2..3610eb96f1 100644
--- a/data/rus/settings/autorun.dat
+++ b/data/rus/settings/autorun.dat
@@ -4,7 +4,7 @@
 # If delay is negative, wait for termination of the spawned process. Otherwise, simply wait
 #
 #/SYS/CROPFLAT "XS800 YS480"	   1	# set limits of screen
-#/SYS/LOADDRV	  "COM_MOUSE"	   1	# serial mouse driver
+#/SYS/LOADDRV	  "COMMOUSE"	   1	# serial mouse driver
 #/SYS/DEVELOP/BOARD   ""	   1	# Load DEBUG board
 #/SYS/refrscrn	      ""	   1	# Refresh screen
 /SYS/LOADDRV         "RDC"        1    # videodriver for RDC M2010/M2012
diff --git a/data/sp/settings/autorun.dat b/data/sp/settings/autorun.dat
index 70705dfce2..3610eb96f1 100644
--- a/data/sp/settings/autorun.dat
+++ b/data/sp/settings/autorun.dat
@@ -4,7 +4,7 @@
 # If delay is negative, wait for termination of the spawned process. Otherwise, simply wait
 #
 #/SYS/CROPFLAT "XS800 YS480"	   1	# set limits of screen
-#/SYS/LOADDRV	  "COM_MOUSE"	   1	# serial mouse driver
+#/SYS/LOADDRV	  "COMMOUSE"	   1	# serial mouse driver
 #/SYS/DEVELOP/BOARD   ""	   1	# Load DEBUG board
 #/SYS/refrscrn	      ""	   1	# Refresh screen
 /SYS/LOADDRV         "RDC"        1    # videodriver for RDC M2010/M2012
diff --git a/drivers/mouse/commouse.asm b/drivers/mouse/commouse.asm
index dca32a676c..7ae736322f 100644
--- a/drivers/mouse/commouse.asm
+++ b/drivers/mouse/commouse.asm
@@ -31,6 +31,9 @@ include '../fdo.inc'
 ; 2nd byte    0    X5    X4    X3    X2    X1    X0
 ; 3rd byte    0    Y5    Y4    Y3    Y2    Y1    Y0
 
+; optional: (logitech extension protocol)
+; 4th byte    0    MB     0     0     0     0     0
+
 struct com_mouse_data
 
         port            dw ?
@@ -244,37 +247,35 @@ irq_handler:
         sub     dx, 5
         in      al, dx
         and     al, 01111111b   ; clear MSB (use 7 bit words)
+        test    al, 01000000b   ; First byte indicator set?
+        jnz     .FirstByte
 
 ; Check which data byte we are reading
-        cmp     [esi + com_mouse_data.offset], 2
-        ja      .reset
+        cmp     [esi + com_mouse_data.offset], 1
+        jb      .SecondByte
         je      .ThirdByte
-        jp      .SecondByte
+        ja      .FourthByte
 
 ; read first data byte
-        test    al, 01000000b   ; First byte indicator set?
-        jz      .reset
+  .FirstByte:
         mov     [esi + com_mouse_data.data+0], al
-        inc     [esi + com_mouse_data.offset]
+        mov     [esi + com_mouse_data.offset], 0
         jmp     .read_loop
 
 ; read second data byte
   .SecondByte:
-        test    al, 01000000b   ; First byte indicator set?
-        jnz     .reset
         mov     [esi + com_mouse_data.data+1], al
         inc     [esi + com_mouse_data.offset]
         jmp     .read_loop
 
 ; read third data byte
   .ThirdByte:
-        test    al, 01000000b   ; First byte indicator set?
-        jnz     .reset
         mov     [esi + com_mouse_data.data+2], al
+        inc     [esi + com_mouse_data.offset]
 
 ; Data packet is complete, parse it and set mouse data
 
-; Buttons
+        ; Left and Right Buttons
         mov     al, [esi + com_mouse_data.data+0]
         mov     ah, al
         shr     al, 3           ; right mouse button
@@ -285,14 +286,14 @@ irq_handler:
         movzx   eax, al
         mov     [BTN_DOWN], eax
 
-; X coordinate
+        ; X coordinate
         mov     al, [esi + com_mouse_data.data+0]
         shl     al, 6
         or      al, [esi + com_mouse_data.data+1]
         movsx   eax, al
         mov     [MOUSE_X], eax
 
-; Y coordinate
+        ; Y coordinate
         mov     al, [esi + com_mouse_data.data+0]
         and     al, 00001100b
         shl     al, 4
@@ -303,14 +304,26 @@ irq_handler:
 
         invoke  SetMouseData, [BTN_DOWN], [MOUSE_X], [MOUSE_Y], 0, 0
 
-  .reset:
-        mov     [esi + com_mouse_data.offset], 0
+        pop     esi
+        mov     al, 1
+        ret
+
+  .FourthByte:
+        inc     [esi + com_mouse_data.offset]
+
+        test    al, 00100000b
+        jz      .end
+        or      [BTN_DOWN], 100b
+        invoke  SetMouseData, [BTN_DOWN], [MOUSE_X], [MOUSE_Y], 0, 0
+
   .end:
         pop     esi
         mov     al, 1
         ret
 
 
+
+
 ; End of code
 
 data fixups