It's a new (2002) variant of the same RAD750 architecture.

  CPUs:  IBM PowerPC 750FX (Single-core,  900 MHz, 32-bit, radiation hardened) 
  RAM:  256 MB (per processor)
  OS: VxWorks (Real-time OS)
  Network: TTEthernet (Time-Triggered Ethernet) at 1 Gbps
  programming: MISRA C++, flight control laws from Simulink adn MATLAB.