Techno Stuff
How They Work - OK games before Bounty
Right, now the nuts-n-bolts of what actually happens during the reset sequence to cause the machine to ratchet up the scores and features to the correct OK game level.
At this point, you've held down the R-button to cause the shutter panel to open and the basic game reset has happened. The exception from normal reset is the green odds unit reset coil was disconnected by one of the switches on the position 29 relay, so the green odds are left wherever they were.
golden gate |
| what happens after reset |
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The brown circuit is what does the magic. A couple switches at the top delay things until the shutter panel is fully open. At that point, the 16 pulse cams are churning out a steady stream of pulses if the position 29 relay is closed. The first thing these pulses hit is a switch in the red stop relay.
After reset, all the stop relays are not powered, so the power is initially directed to the right away from the brown line. In this case, the pulse stream is switched to the red line which connects directly to the red score unit step-up coil.
The red score unit steps up until the red stop relay decides enough is enough, at which time the power is switched back to the brown line and the yellow scores start stepping up.
This process continues for the magic screen feature unit (purple line) and the selection feature unit (blue line). Finally, the two brown lines at the bottom connect to the supersection trip relays, so if the red letter feature unit passed the power to one of those lines, the corresponding supersection is enabled.
The arrangement of this circuit with the successive switching of the stop relays is what creates the characteristic reset sequence when collecting the OK game. I suppose Bally could have hooked up the stop relays in parallel instead of in series, and then you'd wind up with the units all starting to step up at the same time. Somehow it wouldn't be as much fun that way.
The typical problem you have is the game gets stuck stepping up one of the units forever. Note how the "open at top" switches on the score units are not in the circuit path the OK game collection is using, so if the stop relay doesn't work for some reason, the step-up coils on the score units will keep pulsing even though the unit is at the top already.
The entire process is dependant on the stop relays, so I guess we better look at how they work.
Stop relays
The stop relays are in the top right corner of the schematic, which looks like this.
golden gate |
| stop relays |
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Power is coming via a position 29 relay switch into the red letter feature unit on wire #85-9. This power is fed to four separate wiper fingers on the unit (see the unit diagram on the setup page).
The colored highlights on the schematic are drawn to correspond to how the wipers pass the current for an L game. What's changing is the wipers in the bottom boxes, which are the score/feature units being stepped up. For example, the red score disc will step up until wire #14-15 is connected to wire #50-14, at which time the red stop relay is powered and the game moves on to the yellow score disc. Pretty straighforward, I guess.
The switch hanging out on the right hand side is a bypass switch. On the G and D games, no rollovers or before/after 5th is enabled, so the selection feature unit doesn't step up at all. If you don't like that, you need to rewire the spaghetti on the back of the red letter feature unit to connect the rivets to different wires.
