What hands-on exhibits would you put in a Computer Science Center?

A water powered binary logic gate dispay for NAND/NOR/NOT construction of an adder.

Some rotary calculator examples.

Napiers Bones and some worked examples.

A Brunsviga or similar.

Translucent plastic layers of a VLSI circuit which can be taken apart to discuss diffusion layers, boundaries

A model of the shockley/bardeen transistor

Something in the Babbage space.

A linkage/bar computer, analogue computer (Norden bombsight?)

A Mainframe of some kind

A flipchip era PDP8

A pdp11 running, or a rpi5 running a pidp11 with Unix on it

An 11 layer removable disk pack drive

An ATC screen.

A core memory explainer, giant size, or an ex computer core

A Logo turtle in a constrained table with a PC to drive it

I have been wanting to build some mechanical computers.

A mechanical Conway's Games of Life would be nice.