PDP-11 was a bit heavier design, and while it started in 1970s, it was evolving and built with newer designs till 1990s at least (I think last manufactured unit

PDP-11 was a bit heavier design, and while it started in 1970s, it was evolving and built with newer designs till 1990s at least (I think last manufactured units were late 1990s). 1801 line is curious in how it was single chip while the "original" LSI-11 was 2 chip at the time. Meanwhile 1801 was small enough that there are pocket calculators built on it, that a sufficiently deranged EE student can turn into Unix machine.