

AppleCrate II: A New Apple II-Based Parallel Computer - rbanffy
http://home.comcast.net/~mjmahon/AppleCrateII.html

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tectonic
I'm always pleased when I see people finding interesting uses for old hardware
instead of throwing it away.

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alain94040
I actually tried to build something like this (with cables, not stacked) circa
1990. My plan was to implement a snooping protocol in the 16KB of extended
memory. All from discrete TTL components (74LSXXX). Surprinsingly, it never
worked.

Then I moved on to playing with machines with ~100 FPGAs where I can
instantiate as many RISC cores as I want. I'm not sure I'd want to move back
to 6502 for parallel programming.

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mjmahon
I'm glad you found the AppleCrate interesting. I have always found the
Applesoft BASIC programming environment very inviting and satisfying, and the
AppleCrate leverages this accessibility into parallel programming.

The NadaNet network is a low-speed "reinvention" of Ethernet that I developed
to support simple networking of Apple II computers, like the AppleCrate. It
was a very educational project, and has proven to be a robust implementation.

The mechanical compatibility of Apple II boards simplifies construction, and
the low power makes it a desktop-friendly device.

It certainly won't win any speed contests with modern hardware, but the fact
that it runs at a more nearly human-perceptible speed is actually a benefit--
from a "blinkenlights" perspective. ;-)

I should put up some YouTube videos of it in operation. There are already a
few AppleCrate/NadaNet videos up, but they are mostly presentation.

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falstaff
I'd certainly enjoy seeing this marvel in operation. YouTube away please!

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wtracy
I wonder how hard it would be to copy this with old PC boards. Given how non-
standard PC hardware is, I guess you'd have to know what motherboard you've
got before you can start trying to mod it to network boot.

It looks like Coreboot doesn't support any boards older than the Pentium II
timeframe.

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zokier
Look up PXE, many systems already support booting from network. If necessary,
you could add a PXE NIC to the machines.

~~~
wtracy
I figured I'd be dredging up hardware old enough to not support PXE. If it's
possible to add a PXE NIC and boot off the network without a PXE-enabled BIOS,
that is both news to me and very cool.

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joshu
Anyone played w/ a Propeller?

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wtracy
From what I've heard (I have a friend who tried to build a Propeller-based
embedded system) it's a miserable architecture to code for.

It assumes that you're using either assembler or the proprietary "Spin"
language. The accessible memory space is small enough to break the code
generated by C compilers; the only solution I know of involves a mini-
hypervisor that can swaps data in and out of memory.

It also doesn't support interrupts. Their solution? Dedicate an entire core to
busy-waiting for a hardware ready signal. o_O

~~~
joshu
Ugh. Oh well.

