Sound command lines from the control board
Four sound lines leave U6 PA0-PA3, are gated with the sound enable PA4 in Z31, and select one of 15 sounds. The Z31 outputs are normally low and pulse high when a sound is called; a line that never pulses is a control board fault.
Systems
Related tips
- No sound at all
- The wrong sounds or tunes play
- Where coil, sound and lamp commands come from
- System 80 control board chips
- How the control board reset circuit works
- Control board clock frequency
- How the control board drives the displays
- Control board power-on checks
Source: System 80 Service Manual, Gottlieb