Expansion hack: Ejihon Detective Agency
The arcade port stands on its own, finally
In this edition:
Making Ejihon Detective Agency playable as a standalone Saturn game
The Game-Ware “digital magazine” discs
The obscure Super Prologue 21 sampler disc
Get the standalone Ejihon patch from SegaXtreme!
Intro
Ejihon Tantei Jimusho is a puzzle-style arcade game from Sega AM1, the developers behind many Sega arcade games (e.g., The House of the Dead). In the game, you look over artistic scenes that contain hundreds of identical Japanese characters. Your job is to locate the one character that’s different.
Ejihon was developed for the Sega Titan Video arcade platform. That platform’s hardware is very similar to the Sega Saturn console’s (it uses cartridges instead of CDs, but is otherwise the same), so porting ST-V games to Saturn is relatively simple. Indeed, lots of ST-V games were also released as Saturn games — Golden Axe: The Duel, Baku Baku Animal, and Die Hard Arcade are some well-known examples.
Although a Saturn version of Ejihon was produced, it was never released on its own. However, it did appear on the very obscure Super Prologue 21 game sampler, and variants of it were included in editions of the Game-Ware digital magazine. In this article we’ll look at those discs and how to make their versions of Ejihon more readily playable.
Game-Ware, the digital magazine
There were dozens of Saturn demo discs given away with magazines. But General Entertainment had an idea: what if the demo disc was the magazine? Thus was born the Game-Ware series of magazine discs. They have previews of upcoming Saturn games, sure. But they also have ads for consumer goods. And mini games. And mini games that function as ads for consumer goods.
Ejihon is the most substantial thing on the first Game-Ware disc. It also contains a trial version of Digital Pinball: Last Gladiators and several smaller games. Here’s a mini game that promotes hair spray:
And there’s Telecom Town, a mini game that promotes… telecom, I guess?
The Game-Ware Vol. 1 disc normally boots using the file 0STARTUP.PRG. However, the file system also has EJIHON.PRG. What happens if we replace the former with the later using, say, Sega Saturn Patcher?
That’s right, we boot right into Ejihon. Cool! This is the simplest patch I’ve featured on this blog, but it saves you from having to sit through the Game-Ware ads and from navigating its menu.
Super Prologue 21, the Saturn karaoke machine
Sega produced a line of karaoke machines and sold them in Japan. The Prologue 21 and Super Prologue 21 are based on Saturn hardware, and can play Saturn games.
Sega put out a sampler disc that’s locked to Super Prologue 21 hardware called Super Prologue 21 Games Vol. 1. It’s got a couple of weird adult-oriented mini games (they’re labeled “18+” in the menu), but it’s also got the kid-friendly Ejihon.
The hardware locking is pretty halfhearted. Here’s Ghidra’s decompilation of the game disc’s outermost loop:
If you manipulate 0602b344 directly, you can get past the “wrong hardware” screen and jump into the games. For Ejihon you can do:
06003aa2 e204 # Launch mode 4 for EjihonSaturn guru Knight0fDragon developed a patch that lets a standard machine play using his own methodology; there’s a patch at SegaXtreme.
The Ejihon variations
The Game-Ware Vol. 1 and Prologue 21 Games Vol. 1 versions of Ejihon have more features than the arcade version: support for up to 4 players and a “karaoke” mode.
The versions that appear on the later Game-Ware discs are slightly different. They are more connected with the main Game-Ware menu, and don’t have the extra modes. Each one has a different title screen and features different stages:
The original arcade version doesn’t have the karaoke mode, but it does have a hidden sprite test menu that isn’t present in the Saturn versions:
Outro
Playing Ejihon without being able to read Japanese is quite the challenge. I suppose it would be possible to localize it by using the Roman alphabet? If you want to try it, I’ll share my hacking notes.
Thanks for reading Rings of Saturn! I hope you’ve enjoyed this end of year hacking blitz. Send me your suggestions for games to examine; I’ll put them on my list.
Hey how did you access that hidden sprite test in the st-v version?
Would you be willing to make a patch available for the Super Prologue 21 version of Ejihon? Thanks for all your great work by the way!