Quoted from acebathound:
I haven't read through this whole thread, but just wondering if anyone's had their Jurassic Park randomly freak out during a game and start scoring all crazy points and flipping through different modes on the DMD and it doesn't stop until the ball drains. Keeps repeating stuff like DINO DINO DINO DINO DINO DNA DINO DINO. The first time it happened I thought it was part of the game like I hit some Jackpot.. and later realized it was a bug Once the ball drains everything goes back to normal. I had read somewhere that this may be a ramp switch sticking and possibly some bug in the game code.. but thought I'd ask if anyone else had that happen before I dig into my own JP. It's really the only thing that's kept me from enjoying the game.
Oh wow! I am so glad you brought this up.
I know EXACTLY what is happening!
Congratulations... you found a bug in the code! But it's not a bug that anyone would ever see in a perfectly functioning game.
I came across this while working on the code update.
Here is the switch matrix for Jurassic Park:
The one I have highlighted is "Not Used". It would be Switch 28. But there is nothing hooked to this in the matrix. So a perfectly functioning game would never have this switch activate. The only way this switch would activate is if there is a problem in the switch matrix. Most likely a diode issue somewhere in ROW 4 or COLUMN 4.
As you can see, there are other "Not Used" switches (switch 8, 30, 51, 54, and 62). But if something were to trigger those, nothing would ever happen. Why? Because the code tells it to basically ignore those switches. But why does triggering Switch 28 cause the game to freak out? Because the code actually tells the game to go to an illogical place in the program when that switch is activated. So the game basically freaks out until the ball drains.
I am so glad this is happening to you. Why? Because I came across this exact bug while working on the JP code update... I figured no one would ever see this so I forgot about it. But now that you guys are mentioning that you have seen this actually happen in your game, I am going to update it so it will never happen and it will ignore Switch 28 always... just like it ignores all the other unused switches.
So what should you do in the meantime? Look closely at all the diodes on all the switches in ROW 4 and COLUMN 4. Somewhere in there you will probably find a problem such as a bad diode or a short.