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SCP-4904-03 ("Sonic Adventure" version).

Item #: SCP-4904

Object Class: Safe

Special Containment Procedures: All seven instances of SCP-4904 are kept in a climate-controlled Safe-class storage locker at Site-15. Long-term tests (> 1 hour) of SCP-4904 instances should only be conducted on reinforced modified hardware to prevent disc deformation or explosion.

Description: SCP-4904 is a set of modified GD-ROM ("Gigabyte Disc Read-Only-Memory") storage discs manufactured by Sega between the years 1997 and 1999. Each disc is visually indistinguishable from a non-anomalous GD-ROM save for a serial number identifying its origin as a batch of anti-piracy prototype discs created by Sega Japan's enigmatic "R&D-0" division during the height of the Console Wars. Though an estimated 60-100 such discs were known to have been made, only seven survive in the Foundation's possession, each containing a copy of a Sega game released in the late 1990s.1


Sample of SCP-4904-03 visuals at 00:00:00 of gameplay.

When read, SCP-4904 instances cause the optical disc drive's reader to move in unpredictable ways, accessing disc data seemingly at random. Each game boots up as expected, but any action taken past the first loading screen causes the display to deteriorate into chaotic patterns within seconds. Sprites and assets blend into each other in asymmetrical chunks, maps recursively render onto other maps, and soundtracks transform within seconds into incessant, oscillating noise. These eventually stabilise into complex renderings of landscapes and figures wildly inconsistent with the content of the original games and computationally impossible for 1990s-era video-game hardware to render.


Sample of SCP-4904-03 visuals at 01:02:23 of gameplay.

According to Ken Matsuya, R&D-0's former lead hardware programmer, there were many difficulties implementing the discs' anti-piracy encryption measures — a nanometre-scale variable-depth pattern along the discs' grooves allowing for the encoding of proprietary checksums. While the experimental discs could be legibly read from start-to-finish by Sega hardware, diffraction-induced inaccuracies in accessing pointers caused roughly 95% of dereferenced locations to be read as pointers themselves. This resulted in the discs skipping erratically back and forth as the optical reader loaded and accessed disc segments recursively until failure. The result was unplayable. The encryption project was abandoned, and the prototype discs quietly destroyed.

Seven of the double-grooved GD-ROM prototypes are known to have been preserved by Matsuya before their destruction. With the help of improvised Sega hardware, Matsuya spent the next 4 years trying to understand the cause behind the discs' erratic behaviour. Notebooks recovered from his apartment contain numerous sketches of the disc-generated visuals, depicting fractal combinations of landscape and figures seemingly drawn from places outside of the game data themselves, and stylised spinning discs in the shape of eyes.


Sample of SCP-4904-03 visuals at 03:17:52 of gameplay.

Matsuya was later found dead from cardiac arrest in his apartment in August 2003 with large portions of his brain stem and limbic system missing, despite the lack of evidence of any human or non-human intrusion. The strange visuals playing on his television screen at the time of his death led to the investigation of SCP-4904 as the possible cause of death, resulting in its subsequent classification and containment.

No such effects have been observed in testing.

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