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

Hackaday Retro Edition Roundup

In case you’ve forgotten about it, we still have a retro edition of Hackaday. It’s our simple, hand-coded HTML site featuring a few random hacks from Hackaday’s 8-year history. There’s also a retro successes page where our readers can log on with their old boxxen and claim their prize as a master of retrocomputing. Here’s a few retro successes that came in over the past month or so:

Our second OS/2 Warp submission comes from [Chris]. He got an HP Omnibook 800CT running OS/2 Warp 4 to load up our retro site.

A few of you may be wondering what the upper bound of what we consider a retro computer is. [Witek] used a Wyse thin client from the year 2000 to pull up our retro edition. These terrible computers used a Compact Flash card plugged directly into an IDE port to load up Windows CE. Yeah, it’s technically a SSD. [Witek] put the GRUB bootloader on one and loaded up our retro edition with Debian Squeeze. We have too many bad memories of these thin clients, and we’ve got to commend [Witek] for putting the effort into doing something useful with one.

[leadacid] is on a roll. He gave us our first OS/2 Warp submission and has since moved onto an IBM RS/6000. Previously, he got a Macintosh 8100 and a Quadra 840AV to pull up the retro site. Nice job.

Those are all the retro submissions for now, but if you have an old computer lying around, try pulling up our retro site and send it in.

Reliving The BBS Days With A Propeller

Back before the world wide web, self-proclaimed geeks would get our compute on by dialing in to bulletin board systems. In their heyday, these BBSes were filled with interesting people and warez to fill the most capacious 10 Megabyte hard drive. In an attempt to relive the days of the Internet before the Eternal September, [Jeff Ledger] whipped up a tutorial for dialing up BBSes with an updated classic computer.

Instead of doing this tutorial with a C64 or an Apple II, [Jeff] used the Propeller powered Pocket Mini Computer he designed. This computer features 32Kb of RAM inside an eight-core Parallax Propeller along with a BASIC interpreter to run your own programs.

This Mini Computer can connect to BBS systems, but seeing as how acoustically coupled modems are rare as hen’s teeth these days, [Jeff] thought it would be a good idea to log in to the many Internet connected BBS servers using his desktop as a bridge between the Propeller and the Internet.

After [Jeff] got his Propeller computer up and running on a BBS, he was free to play Trade Wars or slay grues in one of the many MUDs still running. Not bad for a demonstration of the Internet of old, and made even better by the use of a Propeller.

Retrotechtacular: Simulating Weather Patterns With A Logic Chip Computer

In 1975, [D. L. Slotnick], CS professor at University of Illinois at Urbana-Champaign faced a problem: meteorologists were collecting a lot more data than current weather simulations could handle. [Slotnick]’s solution was to build a faster computer to run these atmosphere circulation simulations. The only problem was the computer needed to be built quickly and cheaply, so that meant using off-the-shelf hardware which in 1975 meant TTL logic chips. [Ivan] found the technical report for this project (a massive PDF, you have been warned), and we’re in awe of the scale of this new computer.

One requirement of this computer was to roughly 100 times the computing ability of the IBM 360/95 at the Goddard Institute for Space Studies devoted to the same atmospheric computation tasks. In addition, the computer needed to be programmable in the “high-level” FORTRAN-like language that was used for this atmospheric research.

The result – not to overlook the amazing amount of work that went into the design of this machine – was a computer built out of 210,000 individual logic chips at a total cost of $2.7 Million dollars, or about $10 Million in 2012 dollars. The power consumption of this computer would be crazy – about 90 kilowatts, or enough to power two dozen American houses.

We couldn’t find much information if this computer was actually built, but all the work is right there in the report, ready for any properly funded agency to build an amazingly powerful computer out of logic chips.

Digital Zoetrope Uses 18 LCD Displays

[Jasper] sent in a project he, [Quinten], and [Mr. Stock] have been working on for a while. It’s called the Pristitrope and brings the classic 19th centrury paper-based animation device into the 21st century with 18 LCD displays.

The lazy suzan portion of the build was fabricated out of plywood cut on a CNC router and fastened together with the help of a slip ring to transfer power between the stationary and spinning portions of the device. For the electronic part of the build, eighteen LCD displays were connected together on a data bus with each display independently addressable by a microcontroller.

One really interesting feature of the Pristitrope is its ability to detect if it is currently rotating clockwise or counterclockwise. While [Quinten]’s video doesn’t show off the full possibilities of this feature, the spin sensor makes it possible to always have an animation played in the right direction regardless of how the Pristitrope is spun.

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Giving The TRS-80 CoCo A 44 Color Display

As a relic of the early 80s, the TRS-80 Color Computer couldn’t display very many colors. By default, the CoCo could only display 8 colors on the screen at a time, but [John] figured out a way to increase the number of colors displayed using a very simple trick that surprisingly isn’t found in original CoCo games.

The TRS-80 Color Computer uses a Motorola 6847 video display generator to produce color graphics on its display. There are several graphics modes available to CoCo programmers, including a high-resolution black and white mode, and two four-color modes using red, green, blue, and yellow or buff, cyan, magenta, and orange.

These color palettes are extremely limiting, and usually switching between these modes produces a lot of flicker. [John] figured out if he switched the color pallets every 1/60th of a second (i.e. during the vertical blanking interval), he could display 44 colors on the CoCo.

It’s a clever little hack to increase the color palette of the CoCo, and in our opinion should be in the running for winning this season’s Retrochallenge. Sadly, [John] is judge for the Retrochallenge this time around, so he’ll have to settle for earning a Hackaday merit badge.

4004 ROM Emulator Allows Fast Development On Slow Computers

Developing for extremely old computers is a chore; not only are you limited by assembly or pure machine language, there’s also the issue of burning ROMs to actually run your programs. [Frank Buss] came up with a neat solution to developing for the venerable 4004 CPU – build a ROM emulator using a modern microcontroller.

The build started off with a ZIF socket for the 4004 CPU and a 256 byte 4001 ROM chip emulated on a PIC micro. The CPU looked a little lonely sitting in the ZIF socket all by its lonesome, so [Frank] updated his board to allow a 4002 RAM chip to be plugged in as well.

Because [Frank] chose a 4004 for his entry for this season’s retrochallenge competition, we need to point we’re offering a prize for loading our retro site with this CPU. Yes, it’s most likely impossible but nothing worth doing is easy.

You can check out a video [Frank]’s ROM emulator after the break.

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