Aftermarket System 1 CPU boards

Two aftermarket CPU boards replace the original. The Ni-Wumpf board covers every System 1 game through a DIP switch and runs rewritten code, so some rules differ slightly, but its tests are much better. The Pi-1 board stays closer to the original rules and is set to the game in software at first boot; a combined version also replaces the driver, power supply and sound boards.

Systems

• Gottlieb System 1

Related tips

• Powering a System 1 CPU board on the bench
• Spare chips for System 1 boards
• System 1 CPU board connectors
• Check the TC3 jumper plug on the CPU board
• The six Rockwell "spider" chips on the CPU board
• Using an LED to see a bench CPU boot
• CPU board clock check
• Testing CPU input buffers Z29 and Z27

Source: Gottlieb System 1 Pinball Repair from 1977 to 1980, Clay Harrell (pinrepair.com)