Which EPROM format to burn

The simplest route is to set a -17 or -35 MPU for 2732 EPROMs. The first eight Bally games (1977-1978) use the -17 board, which converts easily to two 2716s. From Lost World, the first -35 game, Bally used three 9316 ROMs, which fit better as two 2732s.

Systems

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

Related tips

• Using the test EPROM memory test
• Setting up an MPU for the test EPROM
• Making the test LED for the test EPROM
• U9 signals with the test EPROM running
• U6 select signals with the test EPROM
• Checking the PIA outputs with the test EPROM
• Never use a TMS2716 EPROM
• Test EPROM: the least an MPU needs to run it

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