Turning an M-200 into an M-100, or running two- and three-ROM Bally sets

Remove E32-E33 and E34-E35 and pull the upper 5101 at U13 to make an M-200 act as an M-100. Jumpered for four 2716s, an M-200 runs Bally games with three 2716s (U1, U2, U6). For Bally games with only U2 and U6 2716s, move the E13 link from E14 over to E15, and replace E5-E7 with E1-E5.

Systems

• Stern MPU-200

Related tips

• Stern M-200 MPU jumper settings by ROM set
• How to read Bally jumper charts and identify ROM types
• A Stern M-200 set for 2732s runs any Bally or Stern game 1977-1985
• Why the MPU has ROM jumpers
• How the first-flash ROM test works
• U9 signals with the test EPROM running
• Turning on an ATX PC supply without a motherboard
• After the test EPROM: refit the game ROM and count flashes

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