Uncovering easter eggs in old Mac ROMs

The picture you see above is taken from the ROM of a Macintosh SE made in the  late 1980s. This black and white image remained buried inside old Macs until [Adam] and [Trammell] at NYC Resistor reverse engineered these old Mac ROMs and found a few really cool Easter eggs.

[Adam] and [Trammell] have been dumping ROMs from old computers for a while now. Their modus operandi is finding old 27C-series EPROMs on old computers, prying the out of their comfortable home, slapping them in a breadboard, and wiring up an Arduino clone to dump the data to a computer.

Recently, the guys found an old Mac SE lying on the side of a road in Brooklyn and brought it over to NYC Resistor. They had known about images hidden in the SE ROM, but the guys wanted to know how and where these pictures were stored. After carefully inspecting the binary file generated from dumping the ROM, [Adam] was able to recover three images hidden in every Macintosh SE.

The folks at Apple – especially in the heady days of the Apple II and 68k Macs – hid quite a few Easter eggs in the ROMs of their computers. For instance, the Apple IIgs has audio data stored in the ROM, and the Macintosh Classic hid an entire operating system – System 6.0.3 – in the ROM of the machine.

via Make

Comments

  1. KG4MXV says:

    Ahh the good old days,
    There is another easter egg that if you held down a certain key combo during startup it would scroll the names of all the programmers while playing the monty python theme and at the end a big foot would come down and squash the names and make the fart sound.

  2. Erik Johnson says:

    These weren’t “discovered” by them, these photos have been known (and how to display them in the debugger) for decades. They just merely picked apart the code that was behind packing them and displaying them.

    • SFRH says:

      Not only that, the boot ROMs to practically every Mac ever made have been dumped and floating around the ‘net for years. Heck, MESS even emulates up through the Mac II including the original NuBus cards.

      So the reinvented the wheel by way of dumping ROMs that have already been dumped, and are touting their reverse-engineering skills that any emulator author would have – well done, I guess?

    • KlaymenDK says:

      G 41D89A

  3. SFRH says:

    Too bad that [Adam] and [Trammell]‘s article on how to dump ROMs doesn’t include the all-important 8th step: Contact the MESS (Multi Emulation Super System) team at http://www.mess.org/ with the ROM images that you’ve dumped, so that we can emulate the hardware and preserve its functionality even after the boards have bit-rotted away.

    Some might say it’d be pointless to emulate things as esoteric as an Intel 4004-based clock, or a satellite receiver set-top box. I say everything deserves to be preserved.

    • Johnny. O. Farnen says:

      Agreed. I cannot state how many time saving old “junk” code and hardware saved my ass during my active duty days. I operated on some of the oldest ships in the fleet at the time. Like much of the military, sometimes we still use a thirty year old piece of equipment because it still does the job better than newer, more modern throw away gizmos.

      I cannot even count how many times we got free beer or extra shore leave because I kept a few ammo cans of obsolete hardware and software.

      My favorite was demonstrating how a version of space invaders was hidden in certain cards of the original Block 0 CIWS gun mounts…

      (My trademark trick involved resetting all the flip-flops on a certain board in a certain weapon system by inducing voltages with a large magnet passed over the card in a certain direction.)

  4. mewse says:

    Nearly every damn post on hackaday gets a comment that’s either “I would’ve done it better” or “these guys are terrible, check out [established project]“.

    We get it, you are elite, but check your goddamn ego and let people make their own baby steps into your world without being torn down. Talking shit about neophytes makes your community toxic, just don’t do it.

  5. Matt says:

    Not MAC related, but in the Radio Shack Color Computer 3, there were two easter eggs. One brought up some programmers’ names, while the other brought up a group shot that was encoded into the ROM. Some friends and I hacked the crap out of our ROMs after finding where a lot of these things were hidden and replaced them with our own easter eggs – including our own group and/or individual pictures.

  6. wow says:

    amazing find!! remind me of chip art!!

    Google chip art!!

  7. zebratangozebra says:

    Often wondered if there are pictures or sounds hidden in the PI sequence.

  8. NewCommentor1283 says:

    i wonder if theres a recipie for an edible, bakeable, pie in the RPI …

  9. gz says:

    I remember dumping the apple 2e roms to screen. Somewhere near the end was the words “apple prick”

    Ah my early days of hacking.

    Still, my favorite discovery was opening my amiga 1000 case to discover all the signatures inside it.

  10. Iguana Iguana Powersurgius says:

    Apple sure loved their easter eggs back in the 80s. They kept up the hidden pictures tradition with other machines, like the IIci and the first generation Power Macs.

    The hidden 6.0.3 image on the Classic (Command-Option-X-O on boot) holds another secret of its own. There’s a nested hierarchy of invisible folders that serve as credits. They’re hidden from the Finder, but you can see with with a tool like ResEdit.

    Speaking of which, ResEdit is great for finding stuff. Ambrosia Software hid a load of easter eggs in the resource forks of their games.

  11. veneficus says:

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