Reverse-Engineering NES Tetris to Add Hard Drop

https://www.gridbugs.org/reverse-engineering-nes-tetris-to-add-hard-drop/

by stevebox • 5 years ago

213 41 5 years ago

gridbugs.org

LinguaBrowse• 5 years ago

There are a few broken images there; could those be fixed?

Grustaf• 5 years ago

Maybe someone can reverse engineer the webpage and fix them?

nuller• 5 years ago

I am an html expert. I can help!

ldjb• 5 years ago

The animations use the WebP image format. They work for me in Google Chrome on Android, but some browsers may struggle to display them.

RodgerTheGreat4• 5 years ago

Particularly in the context of low-resolution pixelated graphics using a limited color palette, WebP seems a strictly inferior choice to the universally-supported GIF.

dubcanada• 5 years ago

What browser are you using? Most support animated WebP so you must be using something old?

shakna• 5 years ago

Safari on macOS doesn't support animated WebP [0] except for Big Sur and later, which is pretty recent.

[0] https://caniuse.com/webp

stevebox3• 5 years ago

I just changed the graphics from webp to gif which should address this problem!

RodgerTheGreat4• 5 years ago

Thank you!

atum472• 5 years ago

The show piece at the bottom is kinda cheating, right? One of Tetris challenge is to visualize where the piece will land. Nice project never the less.

bubblesorting2• 5 years ago

Depends on what rule book you're using :) Ghost pieces default to `on` in Guideline Tetris.

Wowfunhappy2• 5 years ago

They also mandate EasySpin/Infinity, which breaks the game, so I basically don’t trust anything the say. >:)

jrrrr• 5 years ago

It's a challenge, but it's an uninteresting one.

digitalsushi2• 5 years ago

I think that today we're just admiring the custom paint job on an old commuter car, and not the design of the car itself.

atum472• 5 years ago

No doubt about that. As I said, it is a nice project. My comment about "cheating" was directed to the player not to the designer of the project. I had the physical game [1] as a child and I don't remember it having the ghost piece.

1 - https://www.google.com/search?q=tetris+original+console&bih=...

marshmallow_12• 5 years ago

I have an official Tetris game. \You can toggle on the show/don't show, though i have only managed to do so by accident.

legohead• 5 years ago

negative. modern tetris has moved way beyond NES' system. there have been many improvements to the game, like a holding piece, hard drop, the ghost piece you mentioned, advanced maneuvers like t-spins, and most interesting of all (to me) is the improved piece selection [1]. you're probably aware of the tall block meme -- when you need it, it never shows up! well that's been more or less solved.

there's also interesting strategies/techniques like 4-wide [2]. there's a whole rabbit hole to follow...

if you want to try out modern tetris, check out jstris [3]. the skill level people have attained is unbelievable [4], and can't be replicated on NES tetris.

[1] https://simon.lc/the-history-of-tetris-randomizers

[2] https://harddrop.com/wiki/Combo_Setups

[3] https://jstris.jezevec10.com/

[4] https://www.youtube.com/watch?v=y3QmU79Vli8

gorkish• 5 years ago

Why release a custom patching tool instead of a standard IPS rom patch?

Karunamon• 5 years ago

Not as fun :)

Besides, you just need the old and new roms to generate an IPS, eg. https://www.marcrobledo.com/RomPatcher.js/

And someone has already requested this: https://github.com/stevebob/mos6502/issues/1

stevebox3• 5 years ago

I honestly did not know that IPS existed until just now! I've added a link to download the patch.

p1necone• 5 years ago

There's a whole community out there around this stuff that you might be interested in reading about. Check out romhacking.net.

wzdd• 5 years ago

Really liked the description of the thought processes behind finding the relevant bits of code through memory inspection in this write-up.

slk500• 5 years ago

amazing stuff! This is what hacking is about

rafaelvasco• 5 years ago

You did a great service for Humanity! Game is now much much better to play.

nicetryguy2• 5 years ago

I have also added hard drop to NES Tetris. Heh. What are the odds?

This hack strays further away from vanilla NES Tetris though and contains further speed, control and graphics modifications; and lacks that fancy looking ghost piece.

https://www.romhacking.net/hacks/4973/

My approach of hard drop implementation was different, honestly i just looped the piece down routine until it hit the ground. His approach breaks the scoring system though, mine doesn't =p

Anyway, this was a great article! Nice rundown of the NES architecture.

stevebox3• 5 years ago

Glad you enjoyed the article! Is there a reference somewhere for how scoring should behave with respect to hard drop? I'm interested in fixing it.

nicetryguy2• 5 years ago

When a piece hits the ground, a point is added for every line you were holding the down button. So, you could probably just take the height difference of the ghost piece and the real piece and add it to the score. Remember to set carry when subtracting =p

I'll bet by directly moving the piece coordinates you bypassed this.

I really like your ghost piece =)

Gary754• 5 years ago

Incredible. Pair this with game genie faster auto shift and I've got myself the ideal Tetris. My only request would be to have the option to disable ghost effect. Thanks so much for making this!

https://igarageband.org/garageband-for-pc-windows-download/

dudleypippin• 5 years ago

Delightful writeup. Two bits that stood out for me:

- The incremental nature of exploration of this type. Often, the results are shown without the messy bits like "then I made it just teleport the piece to a specific spot to test". That matches how many of us operate, I'm sure.

- The use of a number of varied tools from the toolbox. Falling back to the trusty "sort | uniq" after talking about Rust and emulators with built-in memory peeking functionality? Nice!

Reverse-Engineering NES Tetris to Add Hard Drop

Related Stories