Parallel machine made out of 17 stitched-together Apple //e's

Michael J. Mahon's AppleCrate II is a parallel computer stitched together out of 17 enhanced Apple //e main boards from the dim recesses of personal computing history. It's the second iteration of the design (the earlier AppleCrate I was racked in a literal roughly carpentered crate).

Since the Enhanced //e ROM has only $200 bytes available, a new "passive" boot protocol had to be devised. The new ROM code continuously monitors the network for a broadcast BOOTREQ control packet containing the load address and length of the immediately following boot code data. When the boot image has been correctly read from the network, control is passed to its starting address. This passive boot code only needs to read packets from the net, and so occupies just $190 bytes, which comfortably fits in place of the Enhanced //e ROM self-test code at $C600.
The new boot protocol capitalizes on the fact that boot code is sent as a broadcast transaction, so the machines being booted do not need IDs to receive boot code. A page of "second-stage boot" code is added at the front of the slave machine boot image. This code is given control immediately after the boot image is received, and, when enabled by the "GETID daisy chain", it sends a GETID request to the machine that &BOOTed it, making use of the code in the full NadaNet boot image to do so (see the BOOT2 code in the NADA.CRATE listing for details).
The GETID daisy chain functions just as it did in the AppleCrate I. The "first" machine is permanently enabled by connecting its PB2 to ground. AN2 of each machine is connected to PB2 of the "next" machine. The second-stage boot code running in each machine initially sets its AN2. Then it waits until it sees its PB2 go low, enabling it to send its GETID request. When its GETID is successful it drops its AN2, enabling the next machine. Then it clears its video display, writes a banner showing the machine ID, and enters its server loop.

AppleCrate II: A New Apple II-Based Parallel Computer (via The Command Line)

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voiceinthedistance

How long until the white model comes out, I ask?
Robert

Are there really that many (working) Apple //e’s floating around?
- xunker
  
  Many, many millions likely, especially the “Enhanced //e”. I don’t know the actual production numbers but almost every school in North America had some amount of them from the 1980s in to the early 1990s. That’s a lot of Oregon Trail games.
  
  IIRC the Enhanced/Platinum //e had the longest run of any Apple product, being produced in various revisions from 1985 up until 1992.
jphilby

This is quite a fine ultra-geek project (for WHAT I have no idea, but that’s secondary). Although I doubt that Danny Hillman will feel threatened in any way, I’d send a picture of this to Dubai, along with a claim that the next one will be 5000 //e’s high.
Anonymous

When the $ designation was first used, it prolly cost a dollar per byte!
Anonymous

I disapprove of “$” as a hex designation, but googling now, I see that it was used “in older versions of the computerlanguage BASIC.” So perhaps in this one instance it is appropriate ;-)
- Jonathan Badger
  
  The “$” wasn’t just BASIC. That’s how *all* hex numbers were written at the time, at least in the context of the 6502 processor which the Apple 8-bit computers used.
Angryjim

what is this thing in laymans terms? I see that its a bunch of old computers strung together. whaddoesitdo?
- joeposts
  
  It computes parallel-ly. Instead of doing one thing at a time, it can do a bunch of things at once.
- Johnny Coelacanth
  
  He’s hooked them up to make them run as parallel processors. It’s a platform for experimenting with parallel computing, or so the maker sez. It seems like a clever hack which involves professional-grade knowledge of soldering, electronic components and programming. Above my head, but admirably geeky.
oasisob1

Does it run Doom?
Lobster

Y’know, if he was looking for a little more power he could have just asked to borrow my wristwatch.
PaulR

Apple ][‘s were the hacking machines!

I still wish I had mine. I could use the EPROM burner ($49) and the TTL IC tester ($69). Good times.
enkiv2

Such things aren’t actually entirely useless, though they qualify as retrocomputing now…

The Gemini is an example of a (really neat, but failed) commercial product using multiple Apple ][ boards in parallel. If I recall, there were only four of them, and they were actually Apple ][ clones.

For the time, the Gemini was pretty technically advanced. Speech recognition and synthesis, automatic room mapping, obstacle detection and avoidance, voice identification. Procedurally generated stories for the kids. Had a 'tutor mode'. Had a 'security guard' mode (though, unlike the other things listed, that was fairly standard amongst its competitors). Cost eight thousand bucks. Company went out of business eventually.

The schematics and code are still floating around, along with all the documentation. I hope one of these days someone will start fabricating clones. I'd certainly sink some money into them. Especially if the new version used seventeen 6502 boards!
Mark Crummett

Even if it didn’t do anything, it looks cool. And actually functioning? Bonus!
Anonymous

This is high grade hackery. I love it. It reminds me of the time, in 10th grade or so, when I spent almost a full day in my high school computer lab connecting “cassette out” ports of one Apple II to “cassette in” of the next, making a primitive 6-computer ring-shaped network.

The network was used for one thing only: to synchronize the six computers so that they would play a 6-part fugue (ricercar a 6 from the art of fugue) that I had painstakingly entered using an interpreted music language called Forte. Each computer played one voice, and it was actually pretty impressive to hear them play together.
bhtooefr

Here’s an example of what it can do, from 2008:

http://www.youtube.com/watch?v=pa_ONTDm35U

17 mainboards, I believe one is acting as a control board, and the rest are outputting audio.

Not that impressive, until you consider that Apple II audio is… the speaker clicks when the CPU accesses $C030. Access it multiple times quickly, you start to get something resembling sound.
victorvodka

it’s a lot easier to gang up a bunch of arduinos via I2C for a lot more computing power (and code with a lot more current applications) but i guess ease and current applications weren’t a factor here. i have to say what i just said as part of the mental exercise to keep me away from my pile of old 6502 equipment.
EH

Think of what they could achieve if they sprung for the $250 bytes.
FnordX

I would like to just point out that this is how the video game Darwinia starts out. Former computer genius parallels all of the old computers his company created, sets it up in his garage, and *boom* eventual iterative virtual life. You can get the full explanation here:

http://www.introversion.co.uk/darwinia/extras/story/esofa.html

They explain it a lot better than I can.
- spstanley
  
  Also reminds me of Tron….
- Kimmo
  
  I would like to just point out that this is how the video game Darwinia starts out. Former computer genius parallels all of the old computers his company created, sets it up in his garage, and *boom* eventual iterative virtual life.
  
  That’s a sweet game. I’m not surprised it reminds spstanley of Tron, cause it includes recognisers.
Anonymous

LOL – just need to plug in 6 AppleCAT modems, SafeHouse BBS software, and you’re all set to rock back to the 80s.