TTL level serial port (J10):
1 - +3v 2 - RX 3 - TX 4 - GND
It’s important to know that you need a TTL level shifter in order to utilize this port. You can NOT directly connect this port to your PC’s RS232 port.
The MSS and MSS+ uses the same hardware, the MSS+ just comes with a newer firmware version (2.4.x insted of 1.2.x) and is available with larger harddrives (like 500GB)
Pictures of the MSS+ 500gb motherboard