Software Hacks

499 Articles

Super Mario Bros. 35 Lives Again With A Fan-Made Server

June 13, 2021 by 20 Comments

If you liked playing Super Mario Bros. 35, the unique multiplayer battle royale Mario game that Nintendo released last year on the Switch to celebrate 35 years since the original NES version of Super Mario Bros, then it’s likely that you have been disappointed since April. The gaming giant ended support and removed the game’s servers once their 35 year celebrations were over, leaving the game’s players hanging. Happily there’s a solution, because [Kinnay] has presented a reverse-engineered Nintendo game server replacement along with a game patch, that should keep gamers in multi-Mario fun forever.

While it’s a boon for fans of this particular game, the real value here is in introducing us to the reverse engineering work on those Nintendo servers. We learn about their various foibles over several generations of console, and perhaps most importantly we learn something of their inner workings.

Usually when a game server is turned off it’s because the platform it supports is so ancient as to have hardly any users. This time-limited game on an up-to-date platform is unusual then, but since it was made available to subscribers to Nintendo’s online service for free it’s less of a surprise. Certainly not in the same class as the loss of servers for an entire platform.

Thanks [Digiaap] for the tip.

Header image: Elvis untot, CC BY-SA 4.0.

Linux Fu: Databases Are Next-Level File Systems

June 8, 2021 by 61 Comments

It is funny how exotic computer technology eventually either fails or becomes commonplace. At one time, having more than one user on a computer at once was high tech, for example. Then there are things that didn’t catch on widely like vector display or content-addressable memory. The use of mass storage — especially disk drives — in computers, though has become very widespread. But at one time it was an exotic technique and wasn’t nearly as simple as it is today.

However, I’m surprised that the filesystem as we know it hasn’t changed much over the years. Sure, compared to, say, the 1960s we have a lot better functionality. And we have lots of improvements surrounding speed, encoding, encryption, compression, and so on. But the fundamental nature of how we store and access files in computer programs is stagnant. But it doesn’t have to be. We know of better ways to organize data, but for some reason, most of us don’t use them in our programs. Turns out, though, it is reasonably simple and I’m going to show you how with a toy application that might be the start of a database for the electronic components in my lab.

You could store a database like this in a comma-delimited file or using something like JSON. But I’m going to use a full-featured SQLite database to avoid having a heavy-weight database server and all the pain that entails. Is it going to replace the database behind the airline reservation system? No. But will it work for most of what you are likely to do? You bet. Continue reading “Linux Fu: Databases Are Next-Level File Systems” →

The Epic Saga Of Hacking Knights Of The Round

June 8, 2021 by 3 Comments

For the uninitiated, Knights of the Round was a hack-and-slash arcade game released by Capcom in 1991 that rather loosely followed the legend of King Arthur and the eponymous Knights of the Round Table. In it, up to three players make their way from stage to stage, vanquishing foes and leveling up their specific character’s weapons and abilities. But [Sebastian Mihai] was looking for a new way to experience this classic title, so he decided to reverse engineer the game and create his own version called Warlock’s Tower.

Those familiar with the original game will no doubt notice some of the differences right away while watching the video below, but for those who don’t have an intimate knowledge of Arthur’s digital adventures, the major changes are listed on the project’s web page. Among the most notable are the removal of cooperative multiplayer and stage time limits. This turns the game from a frantic beat ’em up to a more methodical adventure. Especially since you now have to compete the game in a single life. If we had to guess, we’d say [Sebastian] prefers his games to have a bit of a challenge to them.

Even if you aren’t interested in playing Warlock’s Tower yourself, the story of how [Sebastian] created it is absolutely fascinating. He started with zero knowledge of Motorola 68000 assembly, but by the end of the project, was wrangling multiple debuggers and writing custom tools to help implement the approximately 70 patches that make up the custom build.

The hundreds of hours of work that went into creating these patches is documented as a sort of stream of consciousness on the project page, allowing you to follow along in chronological order. Whether it inspires you to tackle your own reverse engineering project or makes you doubt whether or not you’ve got the patience to see it through, it’s definitely worth a read. If you’re a Knights of the Round fan, you should also take a look at the incredible wealth of information he’s amassed about the original game itself, which honestly serves as an equally impressive project in its own right.

Modified versions of classic games, known colloquially as “ROM hacks” are fairly common among serious fans who want to see their favorite games improved over time. While they aren’t always as ambitious as Warlock’s Tower, they all serve as examples of how a dedicated community can push a product well beyond the scope envisioned by its original creators.

Continue reading “The Epic Saga Of Hacking Knights Of The Round“ →

An Emulator That Only Plays One Game

June 7, 2021 by 1 Comment

[Ben Smith] had previously implemented a GameBoy Color emulator but decided to make a new emulator that to play just one game called pokegb. The game is, of course, the popular blue edition of Pokemon. While this emulator could play other GameBoy games, the way it was implemented was to support only the opcodes and features that Pokemon Blue used. What’s perhaps even more amazing is that this full emulator is just 582 lines of C++ (using SDL for graphics and input). There is also an obfuscated version that comes in at just 68 lines and in the shape of three Pokeballs. All the code for pokegb can be found on GitHub.

[Ben] goes through a detailed listing of each opcode of the processor, memory, the graphics unit (PPU), and how it interacts with a modern operating system. We love the idea of implementing each opcode one by one and gradually seeing the emulator make it farther and farther through the ROM. The only feature that’s noticeably absent is sound, which would require a significant amount of code to emulate properly.

If you’re interested in a deep dive into the audio chips inside a Gameboy Color, [Ken Shirriff] has already done the research for you.

Wreck Your Mail Before You Check Your Mail

June 5, 2021 by 28 Comments

Every five years or so, I think it’s time to review my e-mail flow. (Oh no!) I run my own mail server, and you should too, but this means that I get to figure out managing and searching and archiving and indexing it all by myself. (Yippee!)

And I’ll be honest — sometimes I’m a bit of a luddite. I actually, literally have been using Mutt, or its derivative NeoMutt for maybe fifteen years, after a decade or so of mouse-intensive graphical mail readers. If e-mail is about typing words, and maybe attaching the occasional image, nothing beats a straight-up text interface. But what a lot of these simple mail clients lack is good search. So I decided to take that seriously.

Notmuch is essentially an e-mail database. It’s an e-mail searcher, tagger, and indexer, but it’s not much else. The nice thing is that it’s brutally fast. Searches and extraction of tagged subsets are faster than sending the same data back and forth to the Big G, and I have a ton more flexibility. It’s awesome. Of course good ol’ Mutt can work with Notmuch. Everything can. It’s Linux/UNIX. Continue reading “Wreck Your Mail Before You Check Your Mail” →

Commodore Inspired Watch Puts BASIC On Your Wrist

June 2, 2021 by 1 Comment

Ask a smart watch owner what their favorite wrist-mounted feature is, and they might say it’s having all their daily information available at a glance, or the ease with which they’re able to communicate with friends and family. If they don’t mention knocking out a few lines in their wearable BASIC interpreter, then you know you aren’t talking to [Nick Bild]. His “C64 Watch” firmware for the LILYGO T-Watch 2020 not only takes some visual inspiration from the Commodore 64, but also lets you relive those early computing glory days with a functional BASIC environment.

Originally [Nick] used a teeny tiny onscreen keyboard to tap out his BASIC programs, but finding the experience to be uncomfortably like torture, he switched over to using USB. Just plug the watch into your computer, open your favorite serial terminal, and you’ll have access to the customized version of TinyBasic Plus running on the watch. To make things  even easier, he’s looking at implementing a web-based terminal over WiFi so you don’t need to plug the watch in.

When you aren’t running BASIC you’ll be treated to a Commodore-themed watch face, complete with the classic READY. prompt. A small battery indicator is hidden up in the top-right corner, and tapping on the rainbow colored “C” will launch the menu. It’s pretty simplistic, but of course what else would you expect given the source material?

Looking ahead, [Nick] says he’d also like to implement a C64 emulator into the firmware so the watch could run original software. We’re a bit skeptical about how practical that would actually be, but we’ll reserve judgement until we see it in operation. He’s also hoping other Commodore aficionados will chime in with their own improvements and new features for the watch.

You might think that a Commodore 64 emulator on your wrist would be the most outlandish way to run your old games and software, but we’d say playing Turrican in a virtual reality microcosm of the 1980s takes the cake.

Continue reading “Commodore Inspired Watch Puts BASIC On Your Wrist” →

One Instruction To Rule Them All: C Compiler Emits Only MOV

May 21, 2021 by 17 Comments

How many instructions do you need to successfully compile C code? Let’s see, you’d need some jump instructions, some arithmetic functions, and — of course — move instructions, right? Turns out you only need the move instruction, which — on x86, at least — is Turing complete.

While the effort is a bit tongue-in-cheek, we have to admit that if you were trying to create your own CPU, this would make for a simple architecture and might have power or complexity advantages, so maybe someone will find a practical use for it after all. If you wanted a C compiler for a simple CPU, this wouldn’t require much to emulate at a byte-code level, either.

Continue reading “One Instruction To Rule Them All: C Compiler Emits Only MOV” →