I am currently working on @jbovenzi's Mad World. It does indeed open the lower ball gate to drop another ball into the trough when you lock a ball in the ball lane. It should not increment the ball count until you drain that ball. I THINK in a stock set up you are supposed load 2 balls. As far as hitting the 2 yellows and advancing the ball while releasing another ball...hmmm I don't know if this one does that. I will look.

HOWEVER... on IPDB there's a commenter who sez you can load 4 balls into the game (not 5, he says the game won't take that) and since the ball lane holds 3 balls, you can supposedly get a 4-ball multiball happening. I have not tried that yet, but I will tonight or tomorrow. Once I get this one working I will video it...or you can come to CAX to play it!

My question is what causes open ball lane light in the left loop to light? I think it's got a bad socket, so I can't get it to light just now, but it does occasionally open the ball lane. Does it alternate with the 1-9 alternator mech like the when-lit one at the top over the C does?

Mighty tempting offer Pard, but I ain't got it in my calendar to git down there before CAX. Oh yeah, I will be down yer way the weekend after tho... but mebbe mebbe the weekend of the 21 is mebbe mebbe...

Hold on, Cowboy... I gotta plan forming...If I don't get this sucker 100% by a week from Friday (20th), I might just take you up on that.

Im'a pm yew when I figger on a few things... Later today...

From the very helpful Larry Z of PPM:

...here's my understanding of how Bally's 1964 "Mad World" is supposed to be set up and operate:

Since it is a 2-player game, there normally would be just 1 ball in the ball trough, NOT 5.
However, since this game has the "Free Ball" feature, it needs to operate via having 2 balls in the all trough, not just 1.

The game is designed with a "Free Ball Alley", which "traps" a ball in that alley, only 1 at a time.
The ball entering the "Free Ball Alley" can only enter when the "Free Ball Gate", towards the upper right side of the playfield, is open.

The "Free Ball Gate" can be opened in only 2 ways:

1. A, B, C and D are rollover lanes at the top of the playfield. Only Lane "C" can open the "Free Ball Gate" when it is lit and the ball rolls through it. I believe it is lit/unlit and alternates with either the 1 or 10-point stepper.
2. There is a rollover lane towards the upper left hand side of the playfield that also will open the "Free Ball Gate" when it is lit and made. Again, this alternates somehow -- not sure what causes it to be lit/unlit, but I think it's the 1 or 10-point stepper unit(s).
The 4 white rollover buttons towards the bottom half of the playfield may also control the "lit" or "unlit" "Free Ball Gate Open" feature, but I'm not absolutely sure about that.

Only once the "Free Ball Gate" is opened, can a ball then possibly enter the "Free Ball Alley", and will "lock" in the top position in the alley. There are 5 such locking positions in the alley. In order to advance the locked ball 1 step further down the alley at a time, a player must either hit 2 of the yellow mushroom bumpers. in the middle of the playfield, or else 1 yellow mushroom bumper and also roll through the rollover lane towards the right side of the middle of the playfield. There are 3 yellow lighted inserts that show this lit or unlit.

When that's done again, the "locked" ball in the alley will then step down one more position. Do that again, and the "locked" ball will advance down the alley and stop again.

When 2 more yellow mushroom bumpers and/or right rollover lane has been made/hit, the "locked" ball in the "Free Ball Alley" will then be released -- but NOT back into the playfield. Instead, the "locked" ball in the "Free Ball Alley" will be sent/diverted back into the ball shooter lane and the ball shooter plunger tip. The player can then shoot that ball again, hence a "free ball".

In other words, I don't believe this is a game designed with truly a "multi-ball" feature with multiple balls rolling around the playfield at once, like on "Star Jet". Instead, it's more like a game designed with just a "free" or "extra ball" feature, but only one can be earned/played at a time.

Also, it is a carryover feature, meaning your opponent or even the next random player can also be awarded the "locked" ball in the "Free Ball Alley" if it happens to be trapped/locked in the "Free Ball Alley" when the next player starts his/her next game, or if/when the next player either 1 or 2 achieves unlocking it.....

He's also going to see if the PPM warehouse has a copy of the manual when he's down there...

Yay Larry!

Nothing that I know of.

Thanks everybody for the detective work! Based on the current description of gameplay, I think Jimmy's MW is pretty much working correctly...BUT...I did notice something while I was experimenting and mjalexan mentioned it in passing:

I noticed that, in the course of trying to figure out how things lit and opened and suchlike, I would occasionally have to latch the free ball relay to get stuff to light. Obviously there is no longer a card under this playfield, so what does it say? When I first set up the game (like at CAX in 2 weeks!), do I have to latch that relay by hand when I load the balls and turn it on? Just that one time, right?

Everything else seems ok, although like jrpinball I am sometimes having ball count issues. But I think it might be because I have an extra ball in the machine. I will see tonight.

Thanks again everybody!

Thank you sir! I think that's exactly what was happening. And then the ball count unit wouldn't advance. That's what I get for believing random dudes on ipdb. I am thinking that when I go out to check this, you will have hit the nail on the head!

Yo @jbovenzi: Looks like she's gonna be ready for CAX!

Ok, I think I have a fully working example of Mad World. mjalexan is completely correct about how the "multiball" is supposed to work. Latch the relay, 2 balls in trough, game starts with open ball gate lights lit. Open the gate, they go off and they don't come on again until a captured ball works its way back to the shooter lane. Now you can plunge that ball and have a 2 ball "multiball" going, but there's no scoring advantage; in fact it inhibits shooting. It's like plunging all 5 balls on an old 60's em. So since the lights come back on once that ball is released, your best bet is to lock the new ball, plunge, work the locked ball down the ladder, and repeat, hopefully forever on one ball count.

In answer to Larry's question, the 4 white rollovers are just one-pointers, but since the 1-9 and the alternator unit are the same thing, they alternate stuff like the outlane specials and the pops.

Speaking of the pops... they seem to have their own ruleset, so to speak. The pops have an entire stepper unit to themselves. It looks like the alternator turns whatever pops are lit on and off, but hitting a lit pop moves the stepper and eventually another pop will light, and then the third. I think they will still cycle off and on with the alternator, but I am still experimenting. @mjalexan, am I close?

This is obviously one of those where it's best as a 2 player, since the ball ladder is a carryover feature.

Thanks again all! See you at CAX!

Sorry, I mean the 0-9 match unit, which steps with every 1 point and alternates through the lighting sequence... Sorry for my inexact lingo.

For a simple looking game, there's a lot going on here.

You are correct. The path to high scoring is to open the gate, trap a ball, move it down the lane and release it, playing the current ball for all it's worth until you drain, plunge the free ball, repeat still on same ball.

@jbovenzi's Mad World was quite popular at Cal Extreme. It's a great game for 2 players too, due to captured ball stealing.

This. No points for opening the gate. Once a ball is in there, C lane scores 10p.