PiStorm – Keeping the Amiga alive

A look at a board that makes the Raspberry Pi 3 emulate various parts of the Amiga as a replacement for the processor. Still has a number of limitations.

The PiStorm, designed by Amiga fan Claude Schwarz [is] one that stands out from the crowd for a variety of reasons. The first is its open hardware; Schwarz doesn’t sell the PiStorm, but instead publishes the source code and design files for anyone to submit to a PCB fabricator. If you don’t fancy fighting with minimum order quantities, the community around the PiStorm organises semi-regular group buys, in which an assembled board, requiring only the headers to be soldered in place, can cost as little as $13 US (around £9 ex VAT).
[…]
Installation is simple – remove the processor from your Amiga 1000, 500 or 500 Plus, and push the PiStorm into its place. Add the Raspberry Pi on top, with a micro-SD card loaded with the lightweight Linux distribution of your choice, and you’re done.
[…]
By default, the PiStorm is configured to act as a Motorola 68020 and a 128MB chip memory expansion. Tweak the configuration and you can increase that to a Motorola 68040 – albeit with a few compatibility issues that are still being worked on – with 8MB of additional Zorro II memory – just about the most you could ever fit in a classic Amiga.

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This is a pretty cool device … it makes me wonder what people are doing with their expanded Amigas.

PiStorm looks cool, but I will use this thread to mention something I ran into a few days ago, yet another Amiga hardware revival thing, looks like basically 68xxx on a FPGA, they call it “Apollo Core 68080”: http://www.apollo-computer.com/

(which of course makes one wistful for Apollo Computer - Wikipedia)

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Ah… Apollo :slight_smile: I used Apollo workstations in 1990-91, at the Norwegian National Defense Research Institute. The Motorola-based workstations were fine, but the DN10000 was an absolute beast.

Amiga users may also be interested in the “Buffee”: New Buffee (ARM 68K Emulator) Accelerator In Development - English Amiga Board (more links in article).

As to the Amiga environment itself, I used to own A500 and A3000, still have the former, and I’d like to work with it, but hours in the day etc. My interest is a bit unusual though, I think, namely having around an operating system that’s not Unix and not Windows is just refreshing, and from open source porting viewpoint quite essential. Though I fully accept that in this I am in a rounding error of a rounding error. From where I stand, “open source” people are Unix bigots all, and I count myself as a Unix bigot :slight_smile:

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Oh, for me too, a major attraction of the Amiga is (and was) an alternative operating system, and a self-hosting development environment. Good value too, at the time.

The PJIT work is very interesting to me - there’s also a work-in-progress JIT 6502 for ARM. Actually, there might be two of those. It’s a way to get another leap in emulated performance. It doesn’t necessarily help the clock-cycle-accurate performance needed for games, but it helps for anything which uses a computer to compute.

PiStorm I find rather interesting because it’s a kind of trojan horse, or russian doll: AIUI there’s a rather complete emulation of a computer living in the CPU socket, which accesses the original motherboard chips only for I/O.

But improved performance, again, isn’t directly applicable to the land of retrogaming, which is where most of the audience is. The Spectrum Next is an exception to that: among other things, they’ve build an improved-performance platform, and got people developing for that platform. The improved performance comes in the form of extra opcodes and higher clock speed - it’s still the kind of platform where you could count cycles and regard the machine as deteministic, if you really wanted to.

Edit: having said which, a nice comment in the Buffee thread:

Compatibility comes from giving the user the power to control the CPU. Need 7MHz? Get 7MHz. Don’t want caches? Turn caches off. Need Lightwave done now? Turn it all back on.

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Even with all these retro processors, you’re still mostly at the mercy of:

  • 1980s-90s capacitors

  • The Amiga video output, which talks to precisely 0 modern monitors

  • One of the custom chips failing. These are close to unobtainium.

For me, without actual Amiga hardware, something like a MiniMig might be better. MiniMig also sell PiStorm boards. They’re based in Toronto.

I think the PiStorm might get over two of those three, as the Pi is running an Amiga emulator and producing its own video output (if I understand correctly.) So the Amiga needs a working keyboard, and perhaps floppy interface, and a good power supply - but possibly not working custom chips.

Clearly, one might feel that this is not quite an amiga, but a Pi in amiga clothing. For me, that’s not too bad: if you have the feel and sound of the genuine keyboard, the smell of the electronics, you have something that might be worth having. It’s certainly a matter of personal taste, and we all know that people differ.

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And the Apollo “68080” if I am reading right is not using old hardware at all, but instead doing 68K and some “SAGA” chipset. If I can have serial console with a bell, that is all the graphics and sound I need :slight_smile:

But then again, the Apollo might not be able to run the true AmigaOS, but instead AROS, which though is supposed to be API compatible… I don’t know, or understand the exact differences, and at the moment do not have the time to delve in. Complicated…

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