[HN Gopher] Reverse-Engineering NES Tetris to Add Hard Drop
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       Reverse-Engineering NES Tetris to Add Hard Drop
        
       Author : stevebox
       Score  : 168 points
       Date   : 2021-03-21 14:14 UTC (8 hours ago)
        
 (HTM) web link (www.gridbugs.org)
 (TXT) w3m dump (www.gridbugs.org)
        
       | wzdd wrote:
       | Really liked the description of the thought processes behind
       | finding the relevant bits of code through memory inspection in
       | this write-up.
        
       | [deleted]
        
       | [deleted]
        
       | gorkish wrote:
       | Why release a custom patching tool instead of a standard IPS rom
       | patch?
        
         | Karunamon wrote:
         | 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
        
           | tenebrisalietum wrote:
           | IPSs work in most emulators though, without having to
           | separately patch your legally acquired ROM file.
        
         | stevebox wrote:
         | I honestly did not know that IPS existed until just now! I've
         | added a link to download the patch.
        
       | atum47 wrote:
       | 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.
        
         | digitalsushi wrote:
         | 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.
        
           | atum47 wrote:
           | 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&b
           | ih=...
        
         | [deleted]
        
         | marshmallow_12 wrote:
         | 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.
        
         | jrrrr wrote:
         | It's a challenge, but it's an uninteresting one.
        
         | bubblesorting wrote:
         | Depends on what rule book you're using :) Ghost pieces default
         | to `on` in Guideline Tetris.
        
       | LinguaBrowse wrote:
       | There are a few broken images there; could those be fixed?
        
         | dubcanada wrote:
         | What browser are you using? Most support animated WebP so you
         | must be using something old?
        
           | shakna wrote:
           | Safari on macOS doesn't support animated WebP [0] except for
           | Big Sur and later, which is pretty recent.
           | 
           | [0] https://caniuse.com/webp
        
             | smoldesu wrote:
             | Thanks for sharing this website, it's insane how far behind
             | the curve Safari is on... well, every technology.
        
               | PurpleFoxy wrote:
               | I have asked a few times at work if we can drop safari
               | support because it's blocking so many new features. No
               | luck so far.
        
             | jwandborg wrote:
             | According to that page, Safari for Mac OS is at least one
             | step behind every major browser except IE. I think it's
             | fair to ask whether the images are broken or the Safari
             | release process is broken.
        
         | [deleted]
        
         | Grustaf wrote:
         | Maybe someone can reverse engineer the webpage and fix them?
        
           | nuller wrote:
           | I am an html expert. I can help!
        
         | ldjb wrote:
         | The animations use the WebP image format. They work for me in
         | Google Chrome on Android, but some browsers may struggle to
         | display them.
        
           | RodgerTheGreat wrote:
           | 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.
        
             | loloquwowndueo wrote:
             | Burn all gifs https://burnallgifs.org/archives/
        
               | RodgerTheGreat wrote:
               | If I follow, you are suggesting that web users protest a
               | format that has been in the public domain for 17 years by
               | instead using a format which has existed for less than 3,
               | and in the process render content inaccessible to anyone
               | not using a bleeding-edge browser?
        
               | loloquwowndueo wrote:
               | I suggest we burn all gifs. Whether that leads to what
               | you said is for you and others to decide :)
        
             | digitalsushi wrote:
             | I mean all the licensing and incompatibility questions
             | aside, one very cool thing about these newer formats is
             | they (intentionally? unintentionally?) reduce our carbon
             | footprint a little bit, by trying to save delivery costs.
             | 
             | It would be pretty neat if my mac could make a thumbnail of
             | a webp on my desktop, though. I mean without installing
             | software, overriding security policies, or turning it into
             | a developer laptop.
        
               | RodgerTheGreat wrote:
               | As a concrete comparison, I downloaded the first webp
               | figure on the page, "soft-drop-animation. The webp is
               | 63,250 bytes.
               | 
               | I used imagemagick to convert this file into a gif,
               | resulting in a 119,265 byte file. I then ran the result
               | through gifsicle[0] with maximum compression (-O3) to
               | losslessly optimize it, producing a gif that is 29,711
               | bytes; less than half of the size of the original webp.
               | 
               | As I noted higher on the comment chain, this usage
               | scenario is particularly favorable to the gif format,
               | while webp might come out ahead for photographic sources.
               | 
               | [0] https://www.lcdf.org/gifsicle/man.html
        
               | gmueckl wrote:
               | Is there a good data set on energy requirements for
               | transmission versus compression/decompression of data? Is
               | it really that much in favor of compressed data?
        
         | stevebox wrote:
         | I just changed the graphics from webp to gif which should
         | address this problem!
        
           | RodgerTheGreat wrote:
           | Thank you!
        
       | slk500 wrote:
       | amazing stuff! This is what hacking is about
        
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       (page generated 2021-03-21 23:00 UTC)