diff --git a/usb/README.md b/usb/README.md
index 8a08753..64181b2 100644
--- a/usb/README.md
+++ b/usb/README.md
@@ -10,9 +10,45 @@ The information in this section applies to the following controllers:
 - TCPP-20012: two-handle controller "Type 2", purple skeleton (Sony PlayStation 2)
 - TCPP-20014: Ryojōhen controller (Sony PlayStation 2)
 
-### DGC-255/DGOC-44U
+### DGC-255
 
-No details are available regarding internal functioning.
+This controller shares most of its behaviour with DGOC-44U, but internal details need to be confirmed.
+
+### DGOC-44U
+
+This controller is a HID-compliant joystick with two axes and six buttons. You can find its HID descriptor [here](descriptor_dgoc44u.txt).
+
+|                   |                             |
+|-------------------|-----------------------------|
+| **Product name**  | `電車でGO! コントローラ USB版` |
+| **Manufacturer**  | `TAITO`                     |
+| **Vendor ID**     | `0x0AE4`                    |
+| **Product ID**    | `0x0003`                    |
+| **Serial number** | `TCPP20009`                 |
+
+The controller sends reports to the host (PC) formed by 6 bytes:
+
+| Byte 1 | Byte 2 | Byte 3 | Byte 4  | Byte 5 | Byte 6 |
+|:------:|:------:|:------:|:-------:|:------:|:------:|
+| Brake  | Power  | Null   | Buttons | Null   | Null   |
+
+The values for the brake notch byte are the following. There are 5 unmarked positions between **B8** and **Emergency**, but unlike classic controllers, they are all report the value for **Emergency**.
+
+| Released | B1   | B2   | B3   | B4   | B5   | B6   | B7   | B8   | Emergency | Transition |
+|:--------:|:----:|:----:|:----:|:----:|:----:|:----:|:----:|:----:|:---------:|:----------:|
+| 0x79     | 0x8A | 0x94 | 0x9A | 0xA2 | 0xA8 | 0xAF | 0xB2 | 0xB5 | 0xB9      | 0xFF       |
+
+The values for the power notch byte are listed below.
+
+| N    | B1   | B2   | B3   | B4   | B5   | Transition |
+|:----:|:----:|:----:|:----:|:----:|:----:|:----------:|
+| 0x81 | 0x6D | 0x54 | 0x3F | 0x21 | 0x00 | 0xFF       |
+
+The button byte uses six bits to represent the state of the physical buttons. **0** means that the button is released and **1** that it is pressed.
+
+| Button 1 | Button 2 | Button 3 | Button 4 | Button 5 | Button 6 |
+|:--------:|:--------:|:--------:|:--------:|:--------:|:--------:|
+| B        | A        | C        | D        | SELECT   | START    |
 
 ### DRC-184/DYC-288
 
@@ -29,3 +65,7 @@ No details are available regarding internal functioning.
 ### TCPP-20014
 
 No details are available regarding internal functioning.
+
+## Acknowledgements
+
+Big thanks to [GMMan](https://github.com/GMMan), who has provided the internal details of the DGOC-44U.
diff --git a/usb/descriptor-dgoc44u.txt b/usb/descriptor-dgoc44u.txt
new file mode 100644
index 0000000..3190528
--- /dev/null
+++ b/usb/descriptor-dgoc44u.txt
@@ -0,0 +1,34 @@
+0x05, 0x01,        // Usage Page (Generic Desktop Ctrls)
+0x09, 0x04,        // Usage (Joystick)
+0xA1, 0x01,        // Collection (Application)
+0x09, 0x01,        //   Usage (Pointer)
+0xA1, 0x00,        //   Collection (Physical)
+0x09, 0x30,        //     Usage (X)
+0x09, 0x31,        //     Usage (Y)
+0x15, 0x00,        //     Logical Minimum (0)
+0x26, 0xFF, 0x00,  //     Logical Maximum (255)
+0x75, 0x08,        //     Report Size (8)
+0x95, 0x02,        //     Report Count (2)
+0x81, 0x02,        //     Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
+0xC0,              //   End Collection
+0x75, 0x08,        //   Report Size (8)
+0x95, 0x01,        //   Report Count (1)
+0x81, 0x01,        //   Input (Const,Array,Abs,No Wrap,Linear,Preferred State,No Null Position)
+0x05, 0x09,        //   Usage Page (Button)
+0x19, 0x01,        //   Usage Minimum (0x01)
+0x29, 0x06,        //   Usage Maximum (0x06)
+0x15, 0x00,        //   Logical Minimum (0)
+0x25, 0x01,        //   Logical Maximum (1)
+0x35, 0x00,        //   Physical Minimum (0)
+0x45, 0x01,        //   Physical Maximum (1)
+0x75, 0x01,        //   Report Size (1)
+0x95, 0x06,        //   Report Count (6)
+0x81, 0x02,        //   Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
+0x95, 0x02,        //   Report Count (2)
+0x81, 0x01,        //   Input (Const,Array,Abs,No Wrap,Linear,Preferred State,No Null Position)
+0x75, 0x08,        //   Report Size (8)
+0x95, 0x02,        //   Report Count (2)
+0x81, 0x01,        //   Input (Const,Array,Abs,No Wrap,Linear,Preferred State,No Null Position)
+0xC0,              // End Collection
+
+// 63 bytes