disassemblies・digital archaeology・data preservation
With perhaps the most honest title in all of video gaming, Armadillo Racing is exactly that. But behind its Global Village Coffeehouse-on-LSD tribal aesthetic lurks… a couple of garden-variety dev tools.
Every now and then I strike gold: not another tile viewer or a meaningless data viewer, but something that is really interesting and unique. Riot City was such a gold mine: an English localization for a game that supposedly was onlty released in Japan, and an alternate, spicy ending! Oh, and I guess there’s some data viewers in there too…
The end of 2025 is upon us! Let’s see if we can squeak in one last quickie article before the end of the year. Let’s take a brief look at the disabled debug tools inside Rockman 2: The Power Fighters (or Megaman 2, I suppose, if you’re the kind of person who pronounces NES as “ness”).
We’re back on our CPS2 jam, and we’re looking at Alien vs Predator this time. Buried in its code are a bunch of debugging tools and an alternate staff roll. Compared to the mess that was Progear no Arashi, things were pretty straightforward this time, but there’s still a fair bit of technical complexity we need to cover, so let’s get into it.
Good grief, has it really been almost two years since a proper article was posted? Let’s finally correct that by taking a look at Progear no Arashi and the mess of debug tools and code oddities tucked away in its data.
Let’s take a look at a fighting game with a troubled development history, questionable aesthetic choices, cut characters and hidden debug tools. No, we’re not talking about Tōki Denshō this time. It’s Psikyo’s 1998 fighting game, Daraku Tenshi: The Fallen Angels! In part 1, we’ll look at the game’s hidden development tools and other code mysteries, then in Part 2 we’ll discuss the game’s decimated storyline.
The CPS 2 has a storied history in the emulation scene and hardly needs an introduction. You may think there is nothing left to discover with this hardware, but there are remaining secrets indeed. 24 of them, in fact, in the form of little blue switches…
The game responsible for bringing Mighty and Ray into the world also has a bunch of debugging tools, a ton of cut content, and an interesting development history tucked away.
A solid shooter from Taito with impressive scene transitions and even better music from Zuntata. And a handful of debug tools that took some wrangling to get working. But wrangled they have been!
A competent but relatively uninteresting shooter from Face, the people who are way more famous for Money Idol Exchanger. At least there’s a stage select!
Aurail is a half top-down, half quasi-3D mech based shooting game developed by Westone and published by Sega. It’s fun but a bit difficult to play (or more likely I just suck at it), and there’s a debug/cheat lurking just beneath the surface of the code…
One of the most loved games by fans of the legendary Neo-Geo has a boatload of debug tools and a hidden mini game…
What happens when you cross Breakout with puzzle game versus mode mechanics? You get an adorable hot mess called Blocken!
Witches on their brooms shooting magic missiles is the name of the game, literally: gunhōki translates to “gun broom.” There’s a stage select buried in the code, which is accessible on actual hardware without any code hacks. Neat!
A cute falling blocks style puzzle game with a spellcasting twist and a surprisingly detailed CPU Player debugging tool.
Today we look at Magical Speed, a simple but surprisingly fun Allumer game based on the card game Speed. Turns out there’s a hidden debug menu in the code that’s super simple to re-enable, and lots (LOTS) of unused graphics.
A fun color-matching puzzle game with colorful graphics and cute animations… and bunches of disabled dev functions and unused data!
This is a great little collection of classic Namco games - Pac-Man, Rally X, Dig Dug, Mappy, Galaga and Xevious. Not only are the original games faithfully recreated, there’s an ‘arranged’ mode for each with new graphics, music and gameplay. Oh, and there are bunches of debug tools leftover…
Platformer arcade games are a bit rare, so it’s a shame that Recalhorn (that’s ree-cal-horn, according to the katakana) never got past the location test stage. The graphics are quite nice, even beautiful in some backgrounds, and while the gameplay isn’t ground-breaking, it’s classic and solid. But other people have written better reviews than I ever could, so let’s just jump into what I found…
Phantasm is a creative take on platform shooters, where as a ghost you can posess the bodies of enemies on screen as your person avatar. It’s a well-made game, definitely ‘hidden gem’ status. It also has a very nice selection of debugging tools!
Just a quick article this time around after Zerochan, who is writing an exhaustive Raimais guide, asked me to take a look at the game and see if I could find any debug leftovers. Do level select and invulnerability count? Yes they do! I’ll even throw in a bonus (possibly-)never-before-seen game ending!
Ah, Rod Land, the colorful and popular Jaleco platformer known mostly for its home computer ports, especially on the Amiga. The arcade version is the original, though, and has the most content and best graphics.
It’s been more than two years since I first started taking the game apart. I was new to disassembling code at that point and was making pretty slow progress on understanding what I was finding. Every few months I would pick it back up and chip away at it some more, but never formalized anything into an article.
Well, I decided to finally power through it about a month ago, and here we are. This is the most thorough disassembly I’ve done to date, and this article covers all the interesting bits.
Don’t feel like cheating your way through a Japanese text heavy quiz game to see some of the cute artwork in the game? I’ve got just what you need!
I’ve had this article half-researched and half-written for more than a year now, just sort of laying around. I’ve lacked the interest in finishing it because, frankly, the game is pretty awful. Well, after months of Donpachi and Dodonpachi, it’s time to take a short break with something easy.
Enjoy, I guess?
And now for the article many people have been waiting for: Dodonpachi! Unfortunately, I didn’t make it in time for the 20th anniversary of the game on February 5th, but oh well; better late than never right? This game seems to have a larger following than it’s predecessor, so I’m sure shmup fans will enjoy the re-enabled debugging tools available to play around with. There’s not much else to say, so here we go!
Happy New Year! As promised, here is the writeup on the classic Cave shooter, Donpachi. I’ve decided to do something a little bit different here. Instead of spending so much time writing out the technical details of my findings, I’m instead just providing an overview and MAME cheats to access them. I’ll do the same with the Dodonpachi which will follow later. Later this year I’ll finish up with a detailed technical article about both games. I’m doing it this way in part because the two games share a lot of code (as DDP was clearly built off of DP), and in part because I’ll never get this article out the door in time otherwise. I think there’s a bunch of interesting things here that fans of the game will want to play with, so I’d like to get it published sooner than later.
With all that said, here we go…
It’s been a while, hasn’t it? Some major events have happened in my life, namely planning a trip to Japan later this year and finally returning to college, which have stolen much of my attention. But I still enjoy disassembling and researching old software, and there’s still a backlog of content to finish writing and post, so the site is definitely not dead!
And speaking of backlogs, a few months back my friend AJ on twitter asked that I take a look at Neo Bomberman for the NeoGeo after spotting some suspicious text strings. I started the initial disassembly right away, but didn’t give it a serious examination until recently…
Whoa! The website (in its current form) just passed its one year anniversary! I figured after a year it was FINALLY time to give the design a little refresher with better support for mobile devices, so I spent some time redoing the layout with Bootstrap as well as fixing up some of the design. I think it came out pretty well. Aside from that, I’ve also been hacking on a new game…
If there’s one constant we can rely on, it’s STGs having leftover menus.
Still alive, just been busy with life and other hobbies in the meantime. Data hacking has been on my mind though, and it’s about time to get back to that. For now, I still have a handful of things in my queue to post about, including Shadow Over Mystara for the CPS-2 system!
I seem to be running into this a lot lately, where standard test mode options are disabled or missing from test menus. Honestly, while it’s always gratifying to dig out unused code and make it dance, these finds are kind of boring. But at least this game has some hidden developer credits. Those are always interesting!
Oh, you disabled your debugging options in the test mode menu? We’ll see about that…
Oh man, I am EXCITED! Pocket Fighter was one of the first games I tried picking at when I started hacking old arcade games around the end of last year. I could clearly see from the raw dump alone that there was something hidden away here (it doesn’t get more blatant than a string reading “SECRET TEST”). I tweeted when I found the the entry routine early on, but I could never quite coax the game into loading it properly. Until now…*suspenseful music*
I’m still alive! It’s the busy season at work, so between that and working on other projects, I haven’t been doing much digital archaeology research. Tonight I spent some time doing just that.
So! Dark Seal 2 (known as Wizard Fire in the west) is a fantasy themed beat-em-up. And apparently it has a variety of debug functions remaining…
Life is finally returning to normalcy (whatever that is) after moving into my new house. And that means back to hacking old games in my spare time! Today we’ll look at Akamaru Q Joushou, a game you probably haven’t bothered with unless your Japanese is pretty good. At its heart, it’s a quiz game, but it also has a variety of simple action and word games as well to make things interesting. It has one hell of a collection of debugging tools… and a very interesting developer easter egg!
In Part 1 we examined the disabled Tool Menu, and now we’ll look at the variety of debugging tools left in, plus a couple mysteries. And then I’ll finally be done with this game… for now.
Kyukyoku Sentai Dadandarn, meaning Ultimate Battle Squad Dadandarn and called Monster Maulers in the West, is Konami’s homage to/parody of the sentai genre of TV shows, movies and comics. It’s a solid game and pretty fun; Hardcore Gaming 101 has a good review. And I got way more than I bargained for when I started taking the game apart: so much more that I’ll be making splitting this into two posts. Here we go…
Yet another adult arcade quiz game, this time with some pretty well-drawn and amusing artwork by eromanga artist Miyasu Nonki! A while back I found the text for an alternate test menu, with object and background checks. I could never really track it down properly with the standard MAME disassembly. Maybe I just wasn’t trying hard enough, because when I gave it another go yesterday, this time in IDA, I was finally able to find the routine as well as the non-hacked method for activating it.
I noticed this menu a while back in Magical Error wo Sagase, a puzzle game where you search for differences between two images. In the past I was able to load the routine, but I guess the stack wasn’t set up properly, and it would reset the game immediately after the text appeared. I took a second look at the disassembly tonight and had much better success.
I was pretty unhappy that Land Maker, one of my favorite arcade puzzle games, was one of the few Taito F3 games that did not have the Taito code implemented. Despite that, I still had a hunch there may be some leftovers worth investigating. And I was right! I wouldn’t be making a post otherwise…
Around 1988, Taito began implementing a standard level select code into many of their arcade games. The code was not available to normal players, as it requires the use of the Service button, inside the cabinet. Considering the timing required to press Start and Service in quick succession, it may not have been for cabinet owners either, but instead for the developers who had direct access to the hardware and who may have had those special buttons mapped to something more accessible for testing.
Indeed, some games have more than just level selects, including basic map or object editors and viewers. Some menus allow you to select level numbers well beyond what actually exist in the game, loading non-existant game data when selected. Some menus are very plain, while others obviously had some work put into them. Besides the obvious bonus of easily exploring the game levels without so much work, the menus themselves are sometimes a fascinating look at the developer’s side of the game.
Well, that’s enough mahjong for now… Let’s try something a little more exciting! Like the title screen implies, Riding Fight is a FRONT VIEW SPEED ACTION GAME featuring a couple of hoverboard-mounted radical dudes from the future who punch everything in their path. And it turns out it has a level select screen!
More Mahjong Menus! Next up we have Nyanpai and Musōbana, two games that run on the same Nichibutsu hardware and share most of the same artwork as well as a hidden test menu.
I’ve been playing around with the MAME debugger recently. I loaded up Tinkle Pit, a cute, simple (at first…) maze game and started playing around with altering memory values. I found what appeared to be the value for the current game mode, and after poking it for a bit, I came across an odd screen…