Project Frankenstein: Final Hardware Protocol (v2.0)

Target Drive: Hitachi GCC-4241N

This document details the exact physical wiring required to interface the PC optical drive with the original Xbox System Management Controller (SMC), including raw hardware states for future modifications.

1. IDE Jumper Configuration (CRITICAL)

Before installing the drive in the Xbox, the IDE configuration jumper pins on the rear of the Hitachi drive MUST be set to SLAVE. The Xbox HDD acts as the Master device on the primary IDE channel. Failure to set the DVD drive to Slave will result in an Error 07/08/09 on boot.

2. Power Delivery

Xbox DVD Cable (Yellow)	Hitachi IDE Power Rail
Pin 1 (5V)	Pads 1 & 2 (+5V)
Pin 2 & 11 (GND)	Pads 3 & 4 (GND)
Pin 12 (12V)	Leave Disconnected (Slimlines use 5V only)

3. Hardware State Map: Tray Switches

These are the raw logic states measured at the signal pads of the mechanical leaf switches. Documented here for reference and for the optional "LED Tray Mod" software mapping.

Physical Switch	Tray State: CLOSED	Tray State: OPEN / MOVING
Back Switch (Tray Closed Sensor)	0V (Grounded / Active)	3.3V (Floating / Open)
Front Switch (Tray Open Sensor)	0V (Grounded / Active)	3.3V (Floating / Open)

4. Tray Logic & SMC Wiring

The Xbox SMC uses "Active Low" logic for tray states. PC slimline drives do not natively output a grounded signal when the tray is fully open, requiring an inverter.

Signal	Xbox Pin	Hitachi PCB Solder Point
EJECT	Pin 4	Signal Pad of Eject Button
TRAY_IN (Closed)	Pin 7	Signal Pad of Back Switch
TRAY_OUT (Open)	Pin 9	Collector of 2N3904 Transistor

5. The Inverter Circuit (2N3904)

Build this circuit to correctly spoof the Xbox TRAY_OUT signal.

Collector (C): Wire to Xbox Pin 9.
Emitter (E): Wire to Ground (0V).
Base (B): Wire to a 10kΩ resistor. Wire the other side of the resistor to the Signal Pad of the Front Switch (Tray Open).

Logic flow: When tray opens, Front Switch goes to 3.3V. Transistor turns ON. Xbox Pin 9 gets pulled to Ground (Active Low = Tray Open).