Monday, August 8, 2011

Who framed created PITMAN?

Read another thrilling crime story in Hardcore Gaming 101's Video Game History Casebook #3, in which private investigator derboo finally succeeds in solving his first case.

You might have read our article on the unique Game Boy puzzle game Catrap from last year. It contains a lot of research on the game's origins—in Japan the game is known as PITMAN, and constitutes a remake/sequel to a very old game that designer Yutaka Isokawa submitted to a magazine called Oh!MZ back in 1985. With its source code printed, the game spawned a number of adaptions in the following months and apparently became popular enough in Japan to warrant the revival five years later, as well as an inofficial GBA remake in 2004 and a number of mobile games.

So far little story is going along nicely, until a reader named hitchhikr contributed a post on our forums that threatens to shatter its very foundation: In 2004, he made an MS-DOS port of PITMAN, not based on Isokawa's code, but rather a version that one Sylvain Bizoirre, founder of, had programmed to demo his own interpreter MBasic in 2001.

The catch: A little comment at the top of the 2001 source code saying "a MBasic adaptation from a game I wrote for the Sharp MZ 80K computer in march 1984." Isokawa's PITMAN was printed in August 1985, but his HuBasic source code for the Sharp MZ-700 and MZ-1500 models is labeled 1985.3, still a whole year after the date given by Bizoirre. Neither mentions an original version or even an inspiration, that would make one of the two guilty of plagiarism. But is PITMAN a French game or a Japanese game?

Although mostly identical in their gameplay mechanics, the HuBasic and MBasic source codes are structure very differently—almost as if either version was programmed without seeing the source code of the other, despite both being freely viewable, as Basic programs used to be compiled at runtime with pretty much all 8-bit home computers. The binary level data, however, is exactly the same—save for the fact that Bizzoire's game ends after 22 levels, while Isokawa made it a whooping 50, which would favor the notion that his game could be an upgrade of Bizzoire's. Both feature a level editor (which the 2004 DOS version by hitchhikr omits).

Now what could each programmer's motives look like? Bizoirre wouldn't have much of a reason to consciously fake authorship—in 2001 he just included PITMAN as a simple program to demo his interpreter, nothing important. That also means, however, that he not necessarily would have cared much about its exact origins—he made have found the code among his old files, confused the date, forgotten that he had based it on another's code. Just a bit far fetched, but not impossible.

The stakes were a bit higher on Isokawa's end, at least after his code was printed in the magazine: PITMAN, so it appears, became the most meaningful work in his portfolio until today. Revealing that the game that essentially kickstarted his professional career was in fact a mere convertion at this point probably would have had serious consequences.

Pitmania Unlimited (Mobile)

"Geez, derboo!" You might wanna say after all this fishing in the dark. "Just shut up and ask the guys, willya?!" Well, it's not like I didn't try. Unfortunately, Sylvain Bizoirre apparently has not so long ago made major changes to his life, cutting his ties to the retro computer community entirely. Yutaka Isokawa keeps an online presence, though he stopped posting in fall 2010 and I couldn't get any reply to my emails. It's as if both have fallen off the face of the earth just in time to escape my questioning.

We're nonetheless getting to our happy ending, though, as one keyphrase finally came to my mind: Circulation of Knowledge!

The question remains, after all, as to how Isokawa would have learned about Bizoirre's game in the first place, or vice versa. The French programmer at one point contributed a bunch of photos and coverscans of the Oh!MZ magazine to a Sharp MZ fan page, which shows that he at one point probably had access to the 1985 version. (The collection in the last photo looks large enough to be complete.) If he had seen his game claimed by someone else, wouldn't that have him caused to react in any way? Given, in the 80's (though it is not known when Bizoirre would have acquired the magazines, there has to have been some kind of information flow) it would have been much more difficult to communicate. If Isokawa on the other hand indeed took Bizzoire's game and built upon it, how would he have known about a French homebrew game to begin with?

As it turns out Sylvain Bizoirre used to be president of the French Sharp User Club, the Sharpentiers, from 1982-1986, and editor to the club's own magazine focused on the Japanese manufacturer's range of computers. La Revue des Sharpentiers is fortunately preserved online (at least from issue #5, but #13 contains a complete index of past contents), and combing through the issues finally brought up some result in issue #15—November 1985.

"PITMAN est un jeu inspiré d'une revue japonaise et adapté au S.BASIC. Il fonctionne donc sur MZ 700 et MZ 800 en mode 700 avec BASIC 700."

or translated into English:

"PITMAN is a game inspired from a Japanese magazine and adapted to S.BASIC. It works with MZ 700 and MZ 800 in 700 mode with BASIC 700."

This conversion retains the structure of Isokawa's original code, and also retains his credits. Although it remains a mystery why Bizoirre decided to leave that out in his 2001 reprogrammed version, and how did he get the March 1984 date, we can now safely assert that Yutaka Isokawa is indeed the original creator of PITMAN.

Catrap (Game Boy)

Source Codes:
Isokawa's Original HuBasic Source Code scanned from Oh!MZ August 1985
French S.Basic Source Code from Sharpentiers #15 (November 1985)
Bizoirre's MBasic Source Code from January 2001

I'm trying to get the original version running in an emulator, but it's proving more difficult than I thought, because I can't access many of the necessary special characters in HuBasic, as it replaces their mappings with its own functions. Might try my luck with the French S.Basic version later...


  1. Good job on the research, Derboo. Fascinating stuff.

  2. That's pretty good research. Thanks for the clarification!

  3. Thanks for the informative article. Helped me port this great program to my own favourite 8-bit computer the TRS-80 MC-10: