Sure but 8051 is probably the most widely manufactured processor in human history (along their clones and derivatives) and they were originally fabbed using a 3.5 µm (3500 nm) NMOS process (IIRC). What I'd like to know is what the most advanced process/node has been used to manufacture a production 6502, Z80, or 8051 (or other old standard). Has anyone ever fabbed any of the those CPUs/MCUs at 130 nm or better?

Though, I will say that I'm amazed that anyone is still mass producing digital products on a 6" (if not smaller) wafer using a node that was invented in the mid 1970s (300 mm wafers are the current standard with the next proposed step being 450 mm). I mention digital because a lot of analog gear (and I think some MEMS) is fabbed using what most of us would consider ancient process nodes.