Crystal Maze theme

Posted by HEx 2014-02-02 at 14:35

I've been getting my nostalgia on recently by watching The Crystal Maze. My main takeaway—other than that surely sliding block puzzles aren't that hard?—is that the theme tune badly needs remixing. But before I embarked on such a project, I was aware of a computer adaptation to the Archimedes, a platform with which I'm deeply familiar. I'd played the game (well, the demo) back in the day: I even still had a copy, although it had suffered bitrot and would crash on startup. It presumably contained the theme tune. Now I just had to extract it.

It's been many years since I did any Acorn hacking, but this turned out to be remarkably straightforward. The presence of TrackerModule in the game's Modules directory was a dead giveaway. TrackerModule can play precisely three file formats: Soundtracker, Protracker, and its native format, the almost-lost-to-history Archimedes Tracker. Soundtracker doesn't have any magic numbers to speak of, but even in 1993 nobody used such an obsolete format. Happily the others do: in particular, Archimedes Tracker files start with the string "MUSX", and lo, three data files contain that string. Not quite that easy though, as they're embedded in some kind of custom archive format that I'm not about to reverse engineer.1

Instead I turned to the game itself. Will it unpack the tune for me? I found a pristine copy of the demo—pristine enough to get to the title screen before crashing anyway—and listened for the first time in about two decades to its remarkably poor quality rendition of a fragment of the theme tune. Hardly worth ripping, but no point leaving a job half done. It turned out the crashing was actually an asset: the tune would be left in memory, I didn't even have to break out a debugger! The game normally cleaned up after itself, but that was easily remedied.2

So, the game has quit, and TrackerModule is still loaded. *PlayStatus? Address exception. Well, of course, the tune was in application workspace. Retry outside of desktop, *Modules gives me the workspace address, *PlayStatus gives me the length (also "Converted from Amiga" *sigh*), save it out and we're done.

Since nothing can read Archimedes Tracker these days3, since it started off as an Amiga format anyway, and since I just happen, once upon a time, to have written a converter, I converted the tune back to Protracker. So here it is in all its non-glory. The main executable contains the string "Thanks to Mark Vanstone for the tracker music"—so now we know.

I wonder what the other tunes were.

[1] I'm also struck by how much data compression has come along since the early nineties. These days no compressor I can imagine would leave recognizable ASCII strings behind: what a waste of entropy!

[2] RISC OS's command line interpreter (and its predecessor on the BBC micro) is, at least in my experience, unique in using a single vertical bar as a comment character.

[3] Except xmp, of course.