How the 32 option switches are read

The control board has 32 option switches (four 8-position packs, SW1-SW4) for coin and play settings. They are read by U4 through the DS0-DS3 strobes at power-on or when the replay button is pressed, so a changed setting takes effect only after one of those.

Systems

• Gottlieb System 80
• Gottlieb System 80A

Related tips

• System 80 control board chips
• The battery-backed 5101 RAM uses only data lines DB0 to DB3
• Buffer chips protect the control board LSI parts
• Control board clock frequency
• Control board power-on checks
• Test connector TC1 pins for the address and data bus
• Key pins on the System 80 LSI chips
• How the switch matrix is scanned

Source: System 80 Service Manual, Gottlieb