AppleCrate - parallel computing on 17 apple IIe boards

[BigEd]

See here (and the earlier 8-board system)

It's networked up (and network booted) using NadaNet, and can be used for multi-voice sound synthesis.

(By Michael J. Mahon – July 26, 2008, Revised – May 7, 2010)



(seen here)

[Arlet]

I wonder how hot it gets

[BigEd]

He'll be fine - there's no power supply!

But seriously, the earlier system was better arranged for convective cooling. I'm a big fan of fanless computing. (No pun intended.)

[Nightmaretony]

got a bunch of 2+ and 2E motherboards if anyone wants to duplicate...

[Nightmaretony]

scratch, I should consider for my own music studio, already got ESQ-1s, a theremin and an 1891 pump organ....

[micro_brain]

Wowser.

Didn't know there were so many Apple IIe boards lying around. Thought they'd all been ebayed..

[dclxvi]

Only 17? The last paragraph of this article briefly mentions a "supercomputer" with 256 6502s. (I don't know if Bob and his colleagues actually built it, though.)

http://bob-bishop.awardspace.com/Mandelbrot/index.html

[ElEctric_EyE]

dclxvi wrote:

Only 17? The last paragraph of this article briefly mentions a "supercomputer" with 256 6502s. (I don't know if Bob and his colleagues actually built it, though.)

http://bob-bishop.awardspace.com/Mandelbrot/index.html

That is an awesome find! Talk about a stress test. That's it. May take hours in machine code @2MHz... and there's code too!

[8BIT]

The CC65 package has a Mandelbrot Generator in the sample code. I adopted that for the SBC-3. The code took 7 minutes and 46.4 seconds to run (65816 clocked at 7.1MHz generating a 320x200 color display).

Here a picture of the results:


The article was very impressive. I would like to use some of that code in the future, when I can get the time.

Daryl

[Nightmaretony]

backscratch, boards still offered for anyone who wants them, just pay shipping. will inventory. Mostly 2+, some 2Es in there. doing variation based on my Thinking Dolphin based on Darryl's SBC-1 on paper...

[BigDumbDinosaur]

8BIT wrote:

I recall seeing some of those in a hotel room in Saudi Arabia.

[dclxvi]

8BIT wrote:

The code took 7 minutes and 46.4 seconds to run (65816 clocked at 7.1MHz generating a 320x200 color display).

The code in the article can be sped up in a number of ways, such as using a smaller timeout value than 256 (e.g. 32 as in CC65). 7.1 MHz compared to 1 Mhz Apple II (or 2.5 MHz Apple IIgs) helps too, of course, as would using 16-bit native mode on the 65C816. (I thought about replacing the multiply routine with a faster table-driven technique, like 4AB = (A+B)^2 - (A-B)^2, but I never got around to doing much about that.) The BASIC loop in lines 300-550 would be much faster in assembly, since the all the necessary values already pre-computed; the FP math would be replaced with fixed point math (and the FP to one's complement fixed point conversion wouldn't happen inside the loop any more, nor would saving/restoring the ZP each time), and so on.

One modification I made was to separate the calculation from rendering. I just stored the data in RAM, then I could apply coarse value coloring or fine value coloring to the same data without having to recalculate the data (which was the slow part). (The built-in BASIC graphics routines were ROM-space-optimzed, and thus slow; redisplaying the image was fairly quick using speed-optimized routines.)

The next month's article (Bob doesn't have a scan of it on his website for whatever reason) has a modified BASIC program that uses (if memory serves) the neighboring value technique described in the article. I still have both issues somewhere in the bat cave. It was an interesting, but slow, program. I'd let it run overnight, and I can remember my father making me get out of bed at some ungodly hour of the morning one day because "the computer is beeping". Of course, back then I considered anything before 11:45 A.M. to be some ungodly hour of the morning.

[ElEctric_EyE]

I came across this post at the FPGA4FUN forums.
It's someone's mandlebrot project on a Spartan 3E based Nexys 2 Digilent board, started in April 2011. Check out his Wiki, it's pretty cool, although VHDL coding... I think it's the owner of the forum.

[dog_meat_phantom]

BigEd wrote:

See here (and the earlier 8-board system)

It's networked up (and network booted) using NadaNet, and can be used for multi-voice sound synthesis.

(By Michael J. Mahon – July 26, 2008, Revised – May 7, 2010)



(seen here)

It sure looks cool....I like it.