Revisiting the Macintosh ROM Easter Egg

Posted by timothy on Thursday August 23, 2012 @04:13AM from the when-engineers-play dept.

eldavojohn writes "NYCResistor has published photos of what they call 'Ghosts in the ROM' after dumping Apple Mac SE ROM images from a roadside Motorola 68000-era Macintosh and looking at all the data (they mention an Easter egg reference to this from 1999). They go into some nice detail about the strategy for extracting this data from a discarded unit and noticing structure. There's also other data that they weren't able to identify, which causes one to wonder how many other Easter eggs are lying about in various ROM chips and what modern Easter eggs must be shipping with software/hardware today."

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Re:Chips come in power of 2 sizes by tepples · 2012-08-23 04:44 · Score: 4, Informative

A compression routine that would allow the machine code to fit in the 256kb to begin with?
The ROMs of old world Macs were execute-in-place, meaning they didn't need to be copied to RAM first. Adding compression would require 412 KiB of RAM to hold the decompressed machine code. At the time, that was considered a huge chunk of RAM for a computer like the Mac.