Product Update ~ Apr. 2024

A project log for GameCubePC

The complete GameCube computer that replicates original functionality and adds several new features without sacrificing performance

retromodderRetroModder 04/24/2024 at 22:530 Comments

This product update introduces new features added after the release of the GameCubePC kits.

OCuLink Support

A custom pass-through board was designed and mounted to the rear cover plate to allow for an easily accessible OCuLink connection.

When used with an NVMe-to-SFF-8612 PCIe adapter (shown below) the motherboard can now interface with eGPU docks that support OCuLink, which offers even greater performance out of the mSTX motherboard.

Intel NUC Support

A new bottom shell has been designed to work with the motherboard from an Intel NUC7i5BNK kit. These motherboards are more readily available and offer comparable performance to the mSTX builds. The rear I/O and cover plate were merged into the bottom shell as one part, making assembly of these builds a much easier process.

The NUC does not have headers for additional system fans, so the fan hub board from the mSTX version had to be re-designed to include a speed controller. This breadboard prototype is powered from the NUC's SATA power header, since I was unable to configure the USB header in BIOS to turn power off when the PC was in sleep mode. The fans were changed from 12V to their 5V counterpart.

Since the fans are only 3-wire, PWM control cannot be used as the on-board circuitry doesn't like to have its power switched on and off, even at high frequencies (20-30 kHz). Instead, the fan speed is controlled by varying the voltage supply to the fan, with a minimum of 2.5V to keep the fan alive so air is always circulating through the case. The idle-to-max speed is based on an NTC thermistor that's measuring the ambient air temperature inside the case, which is then fed into a power op-amp circuit to drive the fan with a proportional output voltage.

Min Fan Speed (2.5V) for T < 30°C

Max Fan Speed (5.0V) for T > 35°C

Power Button

A new power switch was selected to replace the original for a better off-the-shelf solution.