I recently hosted a NES Pinball competition, challenging participants to produce TASes that get to 100K in score as soon as possible. I was inspired by this being the dominant category for this game in SRC.
Well, I gave it a go with JaffarPlus and got a surprising result. Turns out you can manipulate the CPU into the extremely improbable situation where it is executing a routine situated in RAM which the PPU seems to modify at the same time. As a result, the routine never returns where it should, but instead continues executing RAM -- with the very fortunate result that some code gets executed that just happens to add 100K score. By abusing this glitch, I get to 100K MUCH MUCH faster than the current RTA WR.
Thanks to 100th_Coin for helping me figure out what was going on. He believes this can open the possibility of ACE, but neither of us have delved much deeper into it. Unfortunately, we haven't realized why you cannot continue playing after the glitch.
I have also created a 1M point movie using JaffarPlus. This is a somewhat more objective goal because it reaches the actual maximum score before overflow. However, given the popularity of the 100K movie, I think this is more relevant to the community.
Enjoy!
Joined: 2/11/2019
Posts: 21
Location: 🇳🇿 New Zealand
If I had a nickel for every time a botting approach lead to a glitch discovery... Yes vote for me!
Seriously though, I would love to hear/read a thorough explanation for this. I thought the game's programming was pretty solid for its time!
Don't mind me, I was born on Friday the 13th.
(I'm not TASing that NES game, okay?)
Joined: 7/11/2016
Posts: 34
Location: 🇰🇷 South Korea
That's quite unexpected!
I'm also curious what the "add 100k score" routine was originally intended for. Sounds like a huge score to increment at once.
Joined: 10/17/2005
Posts: 692
Location: Seattle, WA
Whoa crazy! Does the disabled flipper get stuck in the Up position, is that why the ball gets stuck down there? Apparently the flippers turn back on after you score like 150k according to what I read elsewhere online, is there something going on deeper than that? Sweet glitch find either way.
That's quite unexpected!
I'm also curious what the "add 100k score" routine was originally intended for. Sounds like a huge score to increment at once.
100th_Coin just corrected me. There is no "add 100K score routine", instead:
the reason you gain 100,000 points is because at address $0149, the console executes ff 00 01, running ISC $0100 ,X, incrementing address $100, which is the hundred-thousands digit.
Whoa crazy! Does the disabled flipper get stuck in the Up position, is that why the ball gets stuck down there? Apparently the flippers turn back on after you score like 150k according to what I read elsewhere online, is there something going on deeper than that? Sweet glitch find either way.
It didn't occur to me that the ball gets stuck because the flippers get stuck in the "up" position. This is worth analyzing because maybe by manipulating them at the right time, it might be possible to prevent them from doing this. As said, both 100th_Coin and I are pretty sure this can be fully manipulated (ACE), but haven't delved too deep into it yet
This one here [https://tasvideos.org/UserFiles/Info/639084152851077611], which is linked in the sub notes. It doesn't seem possible to continue playing after the glitch, so for the time being a "max score" movie would consist of "normal" play. We'll keep researching
