That was word of mouth.
This website says 5 independent computers, of which 2 use different hardware and software so as not to fail in the same fashion.
There's several subsystems that have backup functionality or piloting fallback available incase of subsystem failure, and subsystems have internal 2-weay or 3-way redundancy/voting. See eg https://aviation.stackexchange.com/questions/15234/how-does-...