1. Monitor
2.C.P.U
3.Mouse
4. Keyboard
5. Printer
6. Speaker
Depends on how deep you're willing to go to really,
You need one of a few arrangements of flip flop circuits to keep 1-bit state.
Going deeper, you need either NAND, or NOR gates(or a bunch of other ones) and connectors.
Even deeper, you'll require diodes or transistors to build the logic gates.
Beyond that is particle physics.
If you mean sonar it uses echolocation but GPS is signaled from satellite to the internal antenna