SUDDEN DESU

Plus Alpha - High Score Name Entry Easter Eggs

Tue, 21 Jul 2026 13:09:23 +0900

I’m a sucker for games with 1990’s cutesy anime girls, especially when they are paired with hi-tech elements like piloting ships in an STG. Burning Force, which we looked at more than a decade ago, is a great example of this, as is Plus Alpha, a silly and saccharine shooter from Jaleco.

Riot City - English Version, Debug Tools, and "Good" Ending

Tue, 23 Dec 2025 08:47:35 +0900

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…

Rockman 2: The Power Fighters - Debug Mode and Secret Test

Fri, 12 Dec 2025 09:41:31 +0900

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”).

Heavy Nova Prototype - Quick Analysis

Tue, 03 Jun 2025 02:16:00 +0900

We have something a bit special today: a prototype of a Mega CD game! (crowd cheers) Unfortunately, it’s one of, if not the worst game for the system: Heavy Nova. (crowd boos) But it does have something pretty interesting within it’s data which redeems its value a bit. (crowd cheers cautiously)

Let’s take a look.

Alien vs Predator: Debug Tools and Alternate Staff Credits

Sun, 20 Apr 2025 23:09:00 +0900

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.

Tōki Denshō Dev Diary

Tue, 18 Feb 2025 13:48:00 +0900

Tōki Denshō may not be the most refined or serious fighting game in the world, but it’s quirky and has a unique place in Tecmo history. It’s also a miracle that the game even made it to release, suffering during development from an understaffed team, threats and bad ideas from upper management, bad location test results, and the spectre of Dead or Alive that was stealing away the few resources they had.

The details of Tōki Denshō’s development were compiled by the game’s main planner, Jun, as part of the Tōki Gentei dōjinshi. Now, more than six years after I initially promised it, here is a translation and commentary on that development diary.

Progear no Arashi - Debug tools and Code Weirdness

Fri, 07 Feb 2025 22:20:00 +0900

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.

Happy Birthday! 10 Years of Digital Archaeology and Disassemblies

Wed, 06 Mar 2024 03:26:01 +0900

SUDDEN DESU officially turns ten years old in October. My, how time flies…

Daraku Tenshi / Fallen Angels - Part 2 - Cut Characters and Storylines

Tue, 23 May 2023 04:01:00 +0900

We’ve looked at secrets of the game’s data in part 1. Now let’s look at what didn’t even make it past the planning stage, at what could have been…

Daraku Tenshi / Fallen Angels - Part 1 - Debug Tools and Hidden Code

Tue, 28 Feb 2023 04:20:00 +0900

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.

Tee'd Off - A Saucy Secret and Hidden Dev Credits (NSFW)

Wed, 16 Nov 2022 20:40:00 +0900

A Tecmo game featuring boobs? Simply unheard of!

WARNING: This article is slightly NSFW. Turn back now if you’re in a sensitive area or are offended by low resolution pixel breasts.

CPS2 Debug Switches and the Games That Love Them

Thu, 03 Nov 2022 23:24:00 +0900

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…

DoDonPachi 2 - Fancy Debug Tools

Mon, 14 Feb 2022 20:15:00 +0900

We’ve taken a look at Donpachi and Dodonpachi in the past, so of course DDP 2 was going to come up eventually!

Magical Crystals - Debug functions, unused content and the Kaneko ToyBox system

Wed, 12 Jan 2022 00:00:00 +0900

Sometimes you begin disassembling some code thinking, “well, there’s not much here, this won’t take long to research and write about,” and then it spirals out of control and takes up all your free time for multiple weeks.

Anyway, here’s more than you ever wanted to know about what’s hidden away inside Magical Crystals!

Sexy Parodius - Debug Tool

Mon, 20 Dec 2021 22:19:00 +0900

It’s Sexy Parodious! Flying pigs, a horny octopus, and a really janky debug tool hidden away in there.

Unused test menu in Oh! Paipii

Wed, 05 May 2021 16:50:00 +0900

It’s a mahjong game! It’s a falling-block puzzle game! No, it’s Oh! Paipii, a mix of both that isn’t nearly as fun as either of those genres are on their own!

King of Fighters XI - Time Release Menu (and maybe more)

Mon, 12 Apr 2021 12:59:00 +0900

This is just a quickie article to archive some work done via twitter.

Mach Breakers - All sorts of debug tools

Wed, 24 Feb 2021 22:55:00 +0900

Today we’ll look at the sequel to Numan Athletics: Mach Breaker! If you have a particular interest in debugging tools, then strap in because you’re going to have a ball playing with what Namco left in the game. Let’s dive in!

Segasonic the Hedgehog - Debug Tools and So Much More

Fri, 06 Nov 2020 23:35:00 +0900

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 bunch of debug tools in Rayforce / Gunlock

Sat, 18 Jul 2020 22:11:00 +0900

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!

Nostradamus - Stage Select and Loc Test Audit Data

Fri, 29 May 2020 00:16:00 +0900

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 - Invincibility and level select

Sun, 05 Apr 2020 02:12:00 +0900

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…

House of the Dead - Cheat Analysis and Modification

Thu, 12 Mar 2020 00:00:00 +0900

In which we take a look at the House of the Dead cheats and how they can be used to load model data from unused characters.

Quick Intro to Mega CD Development & the Sonic CD MMD Loader

Thu, 06 Feb 2020 13:53:00 +0900

Aside from disassembling games, I also occasionally enjoy assembling them. While I don’t have a lick of talent when it comes to the creative side of game creation, I love to work on the code and technical minutiae. In particular, I enjoy the Sega 16-bit era hardware, and while we have a great library for easy Megadrive development in the form of SGDK, the Mega CD is still a bit difficult to approach. I’d like to change that eventually…

State of the Site 2019

Tue, 31 Dec 2019 08:45:00 +0900

I hope your holidays were happy! Now let’s talk about the upcoming year.

Debug tools in Virtua Fighter 2, Fighting Vipers and Sonic the Fighters - PART 2

Tue, 10 Dec 2019 21:48:00 +0900

Looks like I can finally cross “discovered a previously unknown debug code in a Sonic game” off my bucket list.

Twinkle Star Sprites - Debug Options and Dueling Cakes

Fri, 06 Dec 2019 11:00:00 +0900

One of the most loved games by fans of the legendary Neo-Geo has a boatload of debug tools and a hidden mini game…

Original Strider Hiryuu arcade title screen

Wed, 27 Nov 2019 19:43:00 +0900

Just a quickie article so this isn’t lost to the sands of Twitter.

Blocken - Debug Functions and Graphics Viewer

Wed, 30 Oct 2019 23:00:00 +0900

What happens when you cross Breakout with puzzle game versus mode mechanics? You get an adorable hot mess called Blocken!

Mahou Keibitai Gunhōki (aka Mystic Riders) - Debug Tools with Stage Select

Wed, 30 Oct 2019 23:00:00 +0900

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!

Naname de Magic - Debug Tools and Graphics Viewer

Wed, 30 Oct 2019 23:00:00 +0900

A cute falling blocks style puzzle game with a spellcasting twist and a surprisingly detailed CPU Player debugging tool.

Magical Speed - Hidden Debugging Menu & Unused Graphics

Mon, 23 Sep 2019 09:55:00 +0900

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.

Athena no Hatena - Debug menu and functions

Mon, 12 Aug 2019 08:45:00 +0900

Getting back to our roots of hacking on obscure Japanese quiz/mahjong games that no one else cares about, we’re taking apart Athena no Hatena today!

Pururun - Test Menus, Unused Data, and Prototype Versions

Thu, 02 May 2019 22:19:00 +0900

A fun color-matching puzzle game with colorful graphics and cute animations… and bunches of disabled dev functions and unused data!

Lucky & Wild - Disabled Art Viewers, Sound Test and Round Select with Test Stages

Mon, 04 Feb 2019 20:54:00 +0900

Lucky & Wild is a crossover between arcade racing and lightgun shooting genres with a buddy-cop twist. As always, Hardcore Gaming 101 has a great description of it. Unfortunately, I’ve never seen it in an arcade, but it seems like a lot of fun. The game code has a few disabled test menus as well as a round select that has what appear to be test levels! There are also a small truckload of debug tools that were more than a little bit difficult to get working…

Debug tools in Virtua Fighter 2, Fighting Vipers and Sonic the Fighters

Mon, 03 Dec 2018 10:37:00 +0900

In the beginning, there was Virtua Fighter 2. And Suzuki Yu looked upon the game and saw that it was good. Thus were Fighting Vipers and Sonic the Fighters developed upon its game engine. And, lo, there dwelt within the code of each a bounty of debug tools!

Tōki Denshō - Disabled Test Options, Unused Strings and a Cut Character

Wed, 28 Nov 2018 20:04:00 +0900

Tōki Denshō - Angel Eyes is an enigmatic fighting game from Tecmo and the second (and last) game on their proprietary Tecmo Motherboard System hardware. It was quickly overshadowed by Dead or Alive and sunk into relative obscurity. It would be a stretch to call the game good, but some of its aspects, like the jarring mix of 2D and pre-rendered 3D sprites, make it oddly fascinating. While I don’t normally stray too far from the code, I branched out quite a bit to research this article and it’s been an interesting journey…

Namco Classics Collection - Dev messages and debug tools galore

Wed, 04 Apr 2018 20:24:00 +0900

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…

Recalhorn - Object Debugger and Unused Strings

Mon, 30 Oct 2017 09:07:00 +0900

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 / Avenging Spirit - Dev credits, level select, pause, debug tools, art viewers

Mon, 28 Aug 2017 10:49:00 +0900

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!

Raimais: Pause, level select, invulnerability... and unseen endings!

Mon, 31 Jul 2017 12:34:00 +0900

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!

Rod-Land and R&T - Prototype, location test code, stage editor, and more...

Mon, 03 Jul 2017 10:01:00 +0900

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.

Quiz Sailor Moon - Disabled data viewers and Game pause/reset

Mon, 10 Apr 2017 00:00:00 +0900

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!

Sonic Cosmo Fighter - A Handful of Development Leftovers

Wed, 29 Mar 2017 07:33:00 +0900

I cut my teeth on game hacking and research in the Sonic communities of the early 2000’s - Area 51, SSRG, CulT - and the Sonic arcade games were always something of an enigma to us. It’s been especially exciting to see that these rarities have been finally dumped, including Cosmo Fighter.

I opened the data not expecting to find much and, unfortunately, I was correct. But there are a couple interesting tidbits worth looking at…

Detana! Twin Bee (arcade version) - Extended Dedication Text

Sat, 25 Mar 2017 22:32:00 +0900

Just a small article this time. I came across an intriguing line of text as I was taking apart Detana! Twin Bee (arcade version) recently. Though part of the message shows up normally at the end of the game, it turns out there’s more to the story…

Oedo Fight (Blood Warrior) - Leftover debug tools and more

Fri, 03 Mar 2017 22:08:00 +0900

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?

Dodonpachi - Debug tools, level select and more

Sun, 19 Feb 2017 20:36:00 +0900

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!

Donpachi - Debug Tools and More

Mon, 09 Jan 2017 21:47:00 +0900

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…

Happy New Year!

Tue, 27 Dec 2016 13:00:00 +0900

2016 turned out to be an amazing year for me personally. It was because things were so great that the site didn’t get much love the past few months…

Disabled debug functions in Neo Bomberman

Sun, 05 Jun 2016 20:45:00 +0900

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…

Revisiting the Chrono Trigger Pre-release Leftover Dialogue

Sun, 13 Mar 2016 14:03:00 +0900

Originally written November 2013

Eight years ago (!), we were starting to really dig into the Chrono Trigger Pre-release Demo ROM. I was making it a project to dump all of the dialogue from this Demo version for comparison to the final. I wanted to do a full translation and hoped to find exciting differences in the story. I never finished the translation or comparison, but thankfully the Chrono Compendium completed that project fantastically. While identifying the text blocks and dumping them, we found early on that there was leftover dialogue data from previous versions of the game. Unfortunately, the text was broken: the hiragana and katakana were readable but the kanji was wildly incorrect. That broken text has never been given a thorough examination, until recently when, on a whim, I picked up the project again and documented what I found…

SEGA SONIC BROS. - A previously unknown, unreleased Sonic arcade game?

Fri, 05 Feb 2016 17:56:00 +0900

So it looks like after the Waku Waku Patrol Car and the Popcorn Machine dumps, we may have another rare Sonic arcade game on our hands. This one was unreleased though, never making it past the location test stage.

Burning Force, Part 2 - Version differences, Broken test mode patch, Leftover debugging tools

Sun, 17 Jan 2016 20:39:00 +0900

Here we are at part two of our dissection of Burning Force. We’ll look at some of the less flashy, more technical tidbits I’ve come across while taking the game apart.

Burning Force, Part 1 - Unused translation and extra round select options

Sat, 19 Dec 2015 01:10:00 +0900

Another game with too much stuff to cram into one post! Burning Force is a shooter similar to Space Harrier, only a bit prettier (and newer, to be fair). In part 1 I’ll show a few of the most interesting finds, and then in part 2 we’ll look at some leftover debugging tools, bugs and other miscellany.

Mouja - Unused Test Menu, Debug Functions, Easter Eggs, and More...

Mon, 09 Nov 2015 17:41:00 +0900

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…

Akuu/Air Gallet - Stage select, invincibility, region select and more

Wed, 28 Oct 2015 23:03:00 +0900

If there’s one constant we can rely on, it’s STGs having leftover menus.

Another SECRET MENU! - Dungeons & Dragons: Shadow Over Mystara

Thu, 01 Oct 2015 19:52:00 +0900

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!

Update to the Chrono Trigger unpointed text recovery

Tue, 11 Aug 2015 21:10:00 +0900

Almost two years after its release, we have an update to the Chrono Trigger unpointed text document!

Tinkle Pit Name Substitutions

Tue, 04 Aug 2015 00:00:00 +0900

I took a look at Tinkle Pit a few months back, and recently I’ve tried tackling it again to see if I can’t get that wonky Level Select working. While I’ve made some progress with that (maybe?), I also stumbled across some interesting name substitutions in the High Score Entry screen.

Rezon - ASCII Art and Usage Display

Mon, 27 Jul 2015 22:00:00 +0900

Rezon is a fun little shooter with a couple interesting leftovers (maybe one is an easter egg?). Sadly, neither finds are as amazing as the game’s ending.

Panasonic 3DO Hidden BIOS Dev Messages

Wed, 22 Jul 2015 23:18:00 +0900

Normally I’d save this to post on a rainy day, but I was so amused when I saw it that I really wanted to share it right away: it looks like those wacky 3DO firmware devs left some messages for us to find!

Nebulas Ray Developer Credits and Enabling All Namco Nb 1 Test Options

Mon, 20 Jul 2015 00:00:00 +0900

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!

Disabled Test Options in Bakuretsu Breaker / Explosive Breaker

Tue, 14 Jul 2015 17:30:00 +0900

Oh, you disabled your debugging options in the test mode menu? We’ll see about that…

Pocket Fighter / Super Gem Fighter - Secret Menu (finally) re-enabled!

Wed, 08 Jul 2015 01:27:00 +0900

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*

The Super Famicom CDROM (aka the original PlayStation) appears

Sat, 04 Jul 2015 14:14:00 +0900

I want to believe…

Debug Leftovers in Dark Seal 2 / Wizard Fire

Sat, 04 Jul 2015 02:19:00 +0900

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…

Panel & Variety Akamaru Q - All sorts of test options!

Wed, 15 Apr 2015 00:15:00 +0900

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!

Object menu, debug tools and more in Kyukyoku Sentai Dadandaan (Monster Maulers)! - Part 2

Sun, 15 Mar 2015 12:11:00 +0900

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.

Object menu, debug tools and more in Kyukyoku Sentai Dadandaan (Monster Maulers)! - Part 1

Mon, 09 Mar 2015 19:00:00 +0900

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…

Hidden Menu in Miyasu Nonki No Quiz 18kin

Fri, 27 Feb 2015 20:00:00 +0900

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.

English Text in Kōtetsu Yōsai Strahl

Thu, 19 Feb 2015 19:14:00 +0900

I’m pretty burnt out on tackling Super Gem Fighter / Pocket Fighter right now. I took a little break and did some more research on something quite interesting I had found a while back: English text in Koutetsu Yousai Strahl, a horizontal shooter and a favorite among shmup fans.

EDIT 2018-11-28: As of MAME 0.203, there is a world region dump of Strahl. It contains the English text that was found in the Japanese version, making this article relatively useless. Oh well.

Oops.

Mon, 16 Feb 2015 19:26:00 +0900

The Atari File Management Subsystem (FMS) is the filesystem on an Atari 810 floppy disk.

The 720 sectors of the disk were numbered from 1 to 720, but (perhaps due to poor communication between the different development teams at Atari) the FMS filesystem was designed to support sector addresses in the range from 0 to 719, which meant that sector 720 was not addressable but a nonexistent sector 0 was. This resulted in the filesystem only using the 719 sectors in the overlap between what is addressable and what actually exists, so sector 720 is unused (a waste of a perfectly good 128 bytes).

(Source)

Level Select and More in Magical Error wo Sagase

Sat, 14 Feb 2015 22:11:00 +0900

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.

Unused Menus in Land Maker

Sat, 14 Feb 2015 12:22:00 +0900

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…

The Taito Code

Thu, 12 Feb 2015 22:18:00 +0900

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.

Level Select in Riding Fight

Sat, 07 Feb 2015 23:41:00 +0900

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!

Hidden Options in Niyanpai and Musōbana

Sat, 07 Feb 2015 03:35:00 +0900

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.

Hidden Developer Credits in Two Mahjong Games

Wed, 04 Feb 2015 00:38:00 +0900

Still hacking around with MAME games, and I’m having a blast! This time I opened up Ojanko Yakata (roughly translated as Mahjong Girl Mansion), one of the many, many adult mahjong games to grace game centers of the past. I spotted some ASCII in the memory dump that looked like a hidden developer credits screen and investigated…

Pocket Gal Deluxe - Debug Menu and more

Sat, 31 Jan 2015 05:30:00 +0900

There’s a request on mamecheat for Pocket Gal Deluxe, and I figured I’d give it a go. I played around for a bit, then discovered a nice, juicy string table with some intriguing bits of text. After a few hours of working backwards through the disassembly, I discovered a number of interesting tidbits in the data!

Unused Ending in Momoko 120%

Sun, 25 Jan 2015 00:57:00 +0900

The MAME hacking continues! Momoko 120% is a platform shooter with an interesting history. I’ve always enjoyed it and have begun a full disassembly of the code, partially to learn Z80 assembly and also, as always, to look for any bits of leftover or unused data. And find something I did!

Tinkle Pit leftover demo screen and level select (and more!)

Tue, 20 Jan 2015 22:47:00 +0900

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…

Unreleased Sega arcade prototype "Hammer Away" found and dumped

Mon, 03 Nov 2014 23:18:00 +0900

News was posted today of the finding and dumping of an unreleased vertical shooter by Sega and Santos for the System 18 arcade hardware, called Hammer Away.

Ghosts in the ROM

Mon, 27 Oct 2014 21:35:00 +0900

This is a fascinating older post made by the NYC Resistor group detailing the technical data behind the images left behind in the Apple Mac SE ROM<. As the ROM only used 89kB of the available 256kB, the original development digitized pictures of themselves and hid them away in the remaining space. The article goes into some interesting details about the image format and CPU opcodes.

Damian Ward has also posted some nice shots of the images on hardware: here, here, here and here.

Here We Go Again

Mon, 27 Oct 2014 20:34:00 +0900

2014 is beginning to come to a close.

I’ve wanted to redo this website for a while now, and what better time to get it done than before the new year. The first iteration of the site was simply a front-end for a tumblr blog, which was focused on retro gaming and computer, digital archaeology, interesting hardware, etc., but also contained a fair amount of unrelated interests. It was also one of my first attempts at cobbling together a Javascript SPA; the original code is pretty nightmarish.

I dabbled in rewriting it with AngularJS which was… a learning experience. I got pretty far into it too, but in the end ot was more trouble than it was worth. Besides, while using the tumblr API was a neat exercise, I’d rather keep my posts on my own server, where I can back up and export the database as necessary. Nerd paranoia and desire for control, I guess.

So, here we are with a new blog/CMS system called Chyrp. It seems to be a nice balance of small and functional. I’m sure I’ve missed some nooks and crannies when making the custom theme, but they should be fixed sooner than later.

The content will focus on old video games and computer software, game hacking, digital archaeology, software easter eggs and secrets and retro hardware… I hope you find all of that as interesting as I do! For now I’ll be re-posting some of the more relevant content from tumblr, but I hope to keep it regularly update with new stuff after that.

About SUDDEN DESU

Mon, 01 Jan 0001 00:00:00 +0000

SUDDEN DESU is a blog dedicated to digital archaeology and related topics, such as data preservation, hardware emulation and the culture/history of the video game industry and the players who enjoy the games.

What is Digital Archaeology?

Digital archaeology is part of a wider field of study called archaeogaming. Archaeogaming considers video games as constructs to which archaeological study can be applied, both internally as part of the game experience and externally as data and physical media. Our corner of this field deals with examining the data itself as an “archaeological site” from which we can excavate artifacts to tell us more about the software itself. We can learn how a program is structured, how it uses or doesn’t use hardware, about features that may have been planned but cancelled part way, even about the personality of the devs themselves by way of easter eggs.