Techno Stuff
How They Work - Extra Balls
Odds/Scores Proportioning
surf club |
| scores circuit |
|---|
Ever notice that when the odds are at minimum, the extra balls are easy to get? Think it's a coincidence?
Bally isn't daft. They want the cost of getting an extra ball to be proportional to the additional number of credits you could win if you get one. So let's take a look at how that is accomplished by mixer #2 and the score disc.
Our fantasy is to get the 50V coming in on the yellow wire to exit out along wire #65-4 (green).
Those confusing switches
There are three switches shown in the above image. CU cam #6A is easy...it just cuts off the 50V while the timer cams are turning, which prevents pulses from getting generated to the step-up coils while the mixers are spinning.That leaves us with the two SPDT switches. The rule of thumb which I think always works except when it doesn't is that these switches are drawn as they would be when the game is over and no extra balls are attempted/played. That's all well and good, but the stupid switch blade is drawn right between the two points it can contact to. So in case you haven't found the second rule elsewhere on the site, the switch connects to the point that is counter-clockwise. Another way of looking at it is to rotate the image until the moving switch blade is hanging down, then interprete using the normal switch definition as applied to the moving switch and the point right below/left of it.
If that's confusing, the answer is that after the extra balls relay is tripped, the switch completes the green wire and the other one connects along the blue wire.
In this circuit, it means that mixer #2 and the score disc is inserted in between the yellow and green wires when playing for extra balls. mixer #2 is bypassed when the odds/scores is at the second step (6/20/96 payout level) unless you are playing for extra balls.
In case you were about to lose sleep over it, when the extra balls trip relay is not tripped, the green wire feeds the step-up circuit for the hold feature. Since that is a primary feature of the game, it lights fairly often. Now you know why :-)
Mixer #2
OK, this is nice and straighforward since Bally was nice enough to label the score disc with the payout level. All we need to do is see which wire the 50V from the yellow leaves the score disc on, and then look at the mixer #2 diagram blueprint, to compute the odds of it making it through mixer #2.
| score unit step | payout level | # rivets | odds |
|---|---|---|---|
| reset/1 | 4/16/96 | 3 | 12.50% |
| 2 | 6/20/96 | 3 | 12.50% |
| 3 | 8/24/100 | 13 | 54.17% |
| 4 | 12/32/100 | 13 | 54.17% |
| 5 | 18/48/150 | 9 | 37.50% |
| 6 | 36/72/150 | 9 | 37.50% |
| 7 | 48/100/192 | 5 | 20.83% |
| 8 | 64/200/300 | 5 | 20.83% |
Note on mixer #2 blueprint how multiple solder lugs are tied together to give the odds indicated in the table. When an operator wanted to tighten up the game, they clip wires to disconnect some of the lugs, or they can rearrange the wires.
Glazed Eye Interpretation Revisited
Remember Bobby Joe who was depositing his paycheck into the machine? We decided he had a 71.88% chance of getting through mixer #3. Now all we need to do is ask him what his odds level is and multiply the 71.88 by the number in the above table, giving him a range of 14.97% - 38.94% chance of getting the extra ball unit to step up at least once per coin/credit played.
But we aren't done yet...that 50V coming in on the yellow wire
is supplied by mixer #1 and the reflex unit, so more tables
on the next page.
