The processor plus the RAM is a Turing machine. If you decide in advance what input go to the input pins, regardless of the output, and you just record what go

The processor plus the RAM is a Turing machine. If you decide in advance what input go to the input pins, regardless of the output, and you just record what goes out the output pins, the processor is pretty much a DFA. When you add the RAM, you provide a feedback loop: input depends on previous outputs (in plainspeak, when you write to the RAM, you can read it later). No feedback loop, no Turing machine.