TechCapsules

AI-summarised brief · reviewed before publication

A computer enthusiast has stumbled upon a previously unknown "Easter egg" image file embedded in the ROM code of the 27-year-old Power Macintosh G3, revealing the team that worked on the project. Doug Brown, who documents his experiments and research into older computers on his blog, made the discovery while exploring resources in the Power Mac G3's ROM. The Power Macintosh G3 was manufactured by Apple between November 1997 and August 1999, with the same ROM used for the minitower, all-in-one, and beige desktop models. Brown was using a pair of tools called ROM Fiend and Hex Fiend to examine the G3's ROM resources on a lazy Sunday when he came across two undocumented anomalies. The first was a resource of type HPOE that contained a JPEG image, which had previously been documented in 2014 by another ROM researcher, Pierre Dandumont. However, Dandumont's discovery did not reveal what the JPEG file would display if extracted. The second anomaly, discovered by Brown, was a nitt resource with ID 43, named "Native 4.3." This turned out to be the PowerPC-native SCSI Manager 4.3 code, which was expected and routine. However, Brown noticed some unexpected Pascal strings at the very end of the data, including references to ".Edisk," "secret ROM image," and "The Team." Brown noted that the "secret ROM image" text seemed related to the picture Dandumont had uncovered but was unable to reveal. Further internet research revealed that the phrase "secret ROM image" had been used for Easter eggs in earlier PowerPC Macs. On those machines, users could simply type the text, select it, and drag it to the desktop to display the picture. However, this approach did not work with the secret G3 image. Brown then fed the extracted file into Ghidra, a framework for software reverse engineering, to further analyze the image.