Management Card
The management card is responsible primarily for powering the system. To connect, it uses a smaller half height (48 position, 3 row) DIN 41612 connector with a unique pinout to interface to the backplane. Additionally, it exposes mixed audio from all expansion sources with volume control.
Shown above is the Rev1 board backplane management board. This board is two layer, 2oz copper.
Power
Primarily, the management card exists to provide power to the rest of the system.
Audio
Additionally, the card buffers the mixed audio signals provided by the backplane. The audio is filtered by an active low-pass filter with a 16kHz cut-off frequency. A stereo potentiometer is used to control the volume of the output audio, which is provided on a 3.5mm jack.
Miscellaneous
Like all other expansion cards, the management card supports the I2C bus for out-of-band management, and provides a configuration EEPROM (with serial) at addresses 0b1010000 and 0b1011000.