Dirty Harry Infinite Loop


Anyone ever see this before?

Player earns an extra ball on Dirty Harry, chooses Ramp Shot. Pulls trigger and walks away.

Ball launches and he gets 10M for Magna Force. The ball drains without hitting any other switches. Ball Save. Repeat.

Thankfully the game was decided by this point, so the extra 2 Billion that occurred by letting this run for 20 minutes was inconsequential. Known bug? Faulty game setup? Pinball gods having a laugh?


Yep, I’ve seen this. Seems to be another flavor of a playfield validation glitch. I don’t recall if it’s unique to extra balls.


Very very nice. Great story.

Anyway. There is more issues to this. The game shouldn’t award the “Magna force” points at plunge, when the magnet is mearly used as a diverter in a ball launch sequence.

But secondly, going into a automated “burn-in” loop like this generally shouldn’t happen, with every switch working, during gameplay. Points awarded during this, or not.


I’ve seen this as well, but not all the time. The suggestion about this only occurring on extra balls feels like it could be correct. I can check it out.


No amount of good intentions makes up for lousy programming.


Amazing. Last night at Treadwell I am assuming?


Yeah. We took it in OT.

The extra ball thing may be a red herring. In a later game during an extra ball we did the same thing and Magnaforce went off once, then didn’t catch the ball the 2nd time. Either way, amusing exploit.


Tried this last night, and it didn’t work. On ball save, the ball goes into the pops. Maybe the launcher on your game was too weak to make it to the pops?


Even if that were true, you wouldn’t get a second ball save.

This has to be some kind of buggy behavior.


No, you would get another ball save, because a weak launch would roll down the right orbit and out without hitting any switches, thus not qualifying the playfield. But a normal ball saver launch should go into the pops I think.


Yes it should. There’s an opto that makes the magnet fire that would probably be triggered by most dribble launches and validate the playfield, but yes your scenario is at least possible assuming no slings or inlane/outlanes get triggered.

I think we all agree that the magnet staying on shows definitely that there’s a bug.


Isn’t the magnet always on in some cases? Maybe one of those was true? E.g. isn’t it always lit when multiball is ready, or am I misremembering?


There are times when it’s always lit, but after a ball save shouldn’t be one. As least that’s my recollection. I’m not sure about when MB is ready to go (after that ball save launch), but that would make sense.

It’s always lit during Barroom Brawl mode. Probably Car Chase, too.


I tested all this stuff on my DH tonight. The magnet does not stay lit when MB is ready to go, and it always turns off on the ball save plunge. I didn’t test with EBs.


Is it possible to have the software rev on the game where this incident happended verified?

Secondly it would be helpful to know if the player tilted out. Or was having game modes running at the drain before the incident. The behaviour of the magnet might (by mistake) be reset in a procedure that is omitted when end-of-ball is caused by a tilt. Or similar.

The key trouble shooting this, is, if the points awarded was indeed the Magna Force. In that case, I would say, try Magna Force with drain and with tilt. And in combination with other modes that utilise the magnet.

It is a common thing, that software bugs turn up in more unusual configurations or usage of stuff. Naturally right. Something outside of what the developement team and testing would normally circle. In pinball, special configuration, multi player games, export stuff, false switch inputs etc.

Or, simply by very subtle one-in-a-million timing and combination of state and events. Remember that T2 Super JP from PAPA finals some years ago.


As I remember, the repro for the bug in the OP is to light multiball (magna force comes on untill multiball is started) and then drain with magnaforce lit. On next ball, choose a skillshot that will send the ball toward the magnet which will grab the ball. magnet is still on becuase multiball is still lit. Don’t flip and let it drain, and repeat over and over.

iirc, there is no traditional PF validation on DH.

But, there is a bit of screwiness with draining during ball save, and the game re-launching the ball and giving the player a small grace period where if the ball drains again quickly, it gives it back. (This same behavior can be seen on I500)

Also, this may or may not behave differently with different ball save time settings.