Where coil, sound and lamp commands come from

RIOT U6 port A carries the coil and sound commands: PA0-PA3 plus a sound enable on PA4 are combined in Z31 for the sound lines, and also feed a dual 2-to-4 decoder for the coils; the outhole kicker has its own line from PA7 through buffer Z30. U6 port B carries the lamps: PB0-PB3 become LD1-LD4 through Z32 and PB4-PB7 are decoded into the data strobes. DS0-DS3 also scan the option switches.

Systems

• Gottlieb System 80
• Gottlieb System 80A

Related tips

• Sound command lines from the control board
• Coil command lines during test step 17
• No sound at all
• Checking lamp signals during test step 16
• The wrong sounds or tunes play
• Where to see the switch matrix strobes
• None of the CPU-controlled coils fire
• One or more controlled lamps never light or stay on

Source: System 80 Service Manual, Gottlieb