Extracting Sounds With Acid And UV

Toaplan was a Japanese video game developer in the 80s and early 90s, most famous for Zero Wing, the source of the ancient ‘All Your Base’ meme. Memeology has come a long way since the Something Awful forums and a pre-Google Internet, but MAME hasn’t. Despite the completionist nature of MAME aficionados, there are still four Toaplan games with no sound in the current version of MAME.

The sound files for these games is something of a holy grail for connoisseurs of old arcade games, and efforts to extract these sounds have been fruitless for three decades. Now, finally, these sounds have been released with the help of sulfuric acid and microscopes.

The sounds for Fire Shark, Vimana, Teki Paki, and Ghox were stored on their respective arcade boards inside the ROM for a microcontroller, separate from the actual game ROM. Since the fuse bits of this microcontroller were set, the only way to extract the data was decapsulation. This messy and precise work was done by CAPS0ff, who melted away the epoxy coating of the chip, revealing the microcontroller core.

Even without a microscope, the quarry of this hunt was plainly visible, but there was still no way to read out the data. The built-in read prevention bit was set, and the only way to clear that was to un-set a fuse. This was done by masking everything on the chip except the suspected fuse, putting it under UV, and checking if the fuse switched itself to an unburnt state.

The data extraction worked, and now the MAME project has the sound data for games that would have otherwise been forgotten to time. A great success, even if the games are generic top-down shooters.

Filed under: chemistry hacks