-17, -35 and -133 MPU boards compared

The -35 MPU (AS-2518-35) can run any Bally game from 1977 to 1985; it differs from the early -17 mainly in how the game ROMs are addressed, and has better sockets. The -35 and -133 have about 35 jumper positions, the -17 about ten. The -133 is a -35 with the R113 resistor replaced by diode CR52.

Systems

• Bally MPU AS-2518-17
• Bally MPU AS-2518-35

Related tips

• Telling a -133 MPU from a -35 or -17
• Converting a -133 MPU to a -35
• Convert a -133 MPU to a -35
• Tell a -35/-133 MPU from a -17 by counting J5 pins
• Jumpers for a -35/-133 MPU running two 2732 EPROMs (U2 and U6)
• What changed on the -133 MPU: zero-cross sensing from 6.3 V AC
• Game will not boot, or MPU damaged, after swapping -35 and -133 boards
• Testing an MPU in the game with only J4 connected

Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part Two, Clay Harrell (pinrepair.com)