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TetrisGYM SPS Vulnerability Research

First off the tl;dr for those in a hurry.

My SPS source code has been available since July 2022. It's not the only implementation.

So the short explanation is that the design of pickTetriminoSeed, the function that is the basis for the whole of TetrisGYM SPS (v4 and v5 seeds) has a weakness that Tetris original rom does not. The attached seeds are a list of seeds that fall into the same sequence before piece 100. This is caused by @invalidIndex. There are 276 seeds. Because of how the LFSR in generateNextPseudorandomNumber works, it's not just 276 seeds that do that, it's ~2x that. This is true of just about everything I've checked so instead of 4 million unique seeds, we have about 20k-80k sequences that a player can expect to get (research not complete). And because of how it locks, it continues indefinitely. This is probably beyond the capacity of a person to memorize, but we could see players memorize a small fraction of favorable and unfavorable sequences for a benefit in competition. Let's start the work of writing an improved SPS shall we?

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Spanish vocabulary building


June 17, 2023

A small project I'm current working on has started, so I thought I'd make a short blog about it.

Let's say that someone made a deck of flash cards for SRS. Assuming you want to use the SRS, you can load the deck and let the software do the work. But what if you ...

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Reaper video editing

So you want to use Reaper to edit videos? No problem. Assuming you're on Gentoo Linux or a similar setup, these are the steps to get you sorted.

Reaper video editing screenshot being tested

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Skip Duolingo

Skipping levels in Duolingo after you've already done the test that places you in the level it thinks you should go is quite easy. With three steps and a bit of skill in the language you're learning (or some cheating) you can increase the difficulty of Duolingo to an absurd level.

Step 1: Scroll down the tree and ...

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