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frootloop69

Posted Fri Apr 23, 2021 2:54 pm

Hi all,

Was curious on peoples' views on the piStorm? Looks like a promising feature set for a super low price.
With projects like this and buffee, its got me really excited about upgrade options for my trusty old A1k!

https://www.hackster.io/news/hands-on-w ... SNuXInbSjU

User avatar
nonarkitten

Posted Fri Apr 23, 2021 9:45 pm

Well, full disclosure, I'm good friends with Claude but in direct competition with him.

PiStorm fills a niche of giving good performance and a slew of features missing on the Amiga such as RTG, fast file system, and Ethernet. By leveraging Open Source emulation, PiStorm was able to be brought up quickly and works fairly well.

That being said I see three big problems with the PiStorm.

First is the bottleneck between the Pi and the Amiga. The Pi has no true memory bus on the GPIO headers and the PiStorm "bit-bangs" communication to and from the CPLD which in turn emulates the 68000 bus. There's a lot of transactions and latency here and right now, the PiStorm accesses chip RAM about as fast as a real 68000 if it had an additional wait state with chip RAM.

Which leads to problem number two; the transactional nature of this does not lend itself to efficient emulation. Musashi right now is hitting "modest" 68040 speeds because any chip RAM access has to stop the world and poll the CPLD. I think some of this can be mitigated by adding a FIFO to the CPLD, but I'm not sure that particular CPLD is complex enough to do something like that.

And the third thing is that this is running on Linux. Now, I'll shelve my hatred for Linux for the moment and tell you what the real problem is -- determinacy. See, you're running a processor on a full operating system and that operating system might decide to go do something else for a while. And you can go crazy stripping Linux down and it still might do that. And you could rebuild the kernel with RT extensions, and Linux might still do that. You're at the mercy of Linux.

Which leads me to my final question.

If you have a Pi, why not just run PiMiga on it? It's spanking fast and faster than PiStorm. See, the load of emulating the chipset stopped being an issue around the K3-600 (remember those?) and since most people only use that to emulate games, there's no need to run better than a 1200. For everything else, there's RTG and AHI leaving the CPU to go crazy on JIT and give you performance PiStorm could only dream of.

So in the end, I don't see how it makes any sense. UAE will do better chipset emulation here because it's not bottlenecked. It's a strange solution for a problem we didn't really have.

User avatar
nonarkitten

Posted Fri Apr 23, 2021 9:58 pm

PS: Modern Muscle is ~55MIPS? Really? What an absolute rubbish click-bait headline. I wouldn't even consider Buffee at 1000 MIPS, "Modern Muscle". My 2021 MacBook Air get's like 30,000. Per core. And there are like eight of them. Go home Hack-a-Day, you're drunk.

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Zippy Zapp
CA, USA

Posted Thu Apr 29, 2021 8:11 am

nonarkitten wrote: If you have a Pi, why not just run PiMiga on it? It's spanking fast and faster than PiStorm.
This was exactly my thoughts when I read about it. You are running two computers and two different OSs at the same time. What happens when the Pi crashes? Some devices, such as the pi1541, use bare metal and don't use one of the Pi's OSs. But this is not one of those devices and even if it was I don't think it would be for me. To each his own, though.

I realize it is all how you look at it too. But I prefer a drop-in replacement that does not rely on booting up an OS then starting the emulation then shoe-horning it into the Amiga. Hey, don't get me wrong I think it is great that someone figured out how to do this but for myself, I want a completely transparent experience.

User avatar
intric8
Seattle, WA, USA
Website

Posted Thu Apr 29, 2021 10:13 am

This whole evolution of the Pi being used as a solution for so many various upgrades, I jokingly told a friend of mine last week:

Need an HDMI solution? RPi. Accelerator? RPi. Hard drive? RPi. Modem connection? RPi. You could have a machine with 4 separate RPis running in it!

:D

User avatar
nonarkitten

Posted Thu Apr 29, 2021 5:59 pm

intric8 wrote:
Thu Apr 29, 2021 10:13 am
This whole evolution of the Pi being used as a solution for so many various upgrades, I joking told a friend of mine last week:

Need an HDMI solution? RPi. Accelerator? RPi. Hard drive? RPi. Modem connection? RPi. You could have a machine with 4 separate RPis running in it!

:D
And yet, somehow, just running a single Pi and emulator would be faster. All the Amiga is now is a slow network connection between Pi's emulating subsets of the Amiga.

User avatar
fxgogo
Website

Posted Fri Apr 30, 2021 5:42 pm

I like the activity around these projects. I was interested at first, but decided my hardware is going to be as close to original spec apart from the convenience of goteks and hdmi outputs. Games will be the main focus there. However for my creative applications, I will so much more from running an emulator on my pc or pi400.

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dalek

Posted Sun May 02, 2021 1:25 am

I won't be getting a piStorm but well done to the creator - the more projects that freely document 68000 bus interactions the better!

For me, once the pi is in there I might as well just ditch the rest. It's a purist thing I guess, but I don't see the point in using an Amiga motherboard as a keyboard / mouse dongle, since I'd want to use modern replacements anyway.

I just don't understand the fascination - if you want speed and convenience just use WinUAE. If you want the Amiga's soul coursing through your veins as you bang away the keyboard then use real hardware.

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Kevin Brice
Seattle, WA
Website YouTube

Posted Mon May 03, 2021 3:17 am

I do share the sentiment, in most cases, of it feeling weird to have one or more Pis running their own independent operating systems to replace Amiga subsystems inside an actual Amiga when one Pi would run faster on its own. However, it's worth pointing out there's still hardware that can't otherwise be connected to UAE. Without peripheral requirements, though, I don't really see the point either. It's cheaper to make your A500 faster with a Pi, but it's even cheaper to not have the A500 in the first place and just use the Pi.

User avatar
Bulletdust

Posted Mon May 03, 2021 3:15 pm

As someone that's run a 68030 A1200 accelerator on an Amiga 500 via an ACA500, when it comes to 16bit Amiga's, the CPU hitting chip ram is always an issue and in many cases can result in a system that's slower than if the stock 68000 was fitted - I've mentioned this many times in the past and is an issue regarding the 16bit bus. Under the A1200/A4000 with their 32bit bus there is no problem.

As for the comments regarding Linux, I see no reason to hate a free and very versatile OS that's literally perfect considering the task at hand. It's most likely not running much more than the kernel at the end of the day.





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