Early Bally chime games: -17 MPU and -18 power supply
Bally's 1977-78 chime games (Freedom through Black Jack) use the -18 power supply and the -17 MPU. Freedom has the AS-2518-14 lamp driver; Mata Hari and later use AS-2518-23.
Systems
Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part One, Clay Harrell (pinrepair.com)