Tilt and slam switch types on System 1
The ball-roll tilt inside the coin door area is normally closed and must be closed for the game to boot (System 80 used a normally open one). The pendulum tilt and the weighted tilts under the playfield are normally open; those under the playfield get bent far less when the game is moved.
Systems
Source: Gottlieb System 1 Pinball Repair from 1977 to 1980, Clay Harrell (pinrepair.com)