In my understanding, the hash functions are quite simple and just do things like XOR, and SHIFT, and perhaps ADD/SUB, but not multiply or divide. So the main difficulty would be to do everything at the lowest possible amount of power.
You are correct. The ASIC engineering was routine. It was all about justifying the enormous NRE costs... back in early 2011, BTC was a curiosity and not well known at all. Investors were not easy to convince.
yes, we stopped making application specific integrated circuits (ASIC) back in 1980 in favor of general purpose processors that do all applications decently fast.
there is no rocket science to making an ASIC because we already know how to, and its economically viable again to dust off that knowledge
In my understanding, the hash functions are quite simple and just do things like XOR, and SHIFT, and perhaps ADD/SUB, but not multiply or divide. So the main difficulty would be to do everything at the lowest possible amount of power.
But I could be wrong.