AFAIK Zuse's idea was 'digital physics', ie. that physical laws are algorithms and the Universe can be considered as a (completely standalone, not part of anyth

AFAIK Zuse's idea was 'digital physics', ie. that physical laws are algorithms and the Universe can be considered as a (completely standalone, not part of anything else) computer. Bostrom's idea is that the Universe is (probably) a simulation of something else, running on a computational device embedded inside another Universe.