AROS68K and the Freescale Coldfire CPU

[Iggy]

That's known for the AmigaOS and I'm not suggesting that.

But here we're talking about AROS68K. Which could be patched to avoid compatibility trapping on ColdFire. The only thing in question is how to provide full backwards compatibility with 68K... software or hardware emulation?


P.S. The V5 Coldfire @ 333 MHZ does 610 MIPS.

P.P.S. If what you say is true that it would be about 40 MHz 68040 in "emulated" mode, than maybe that's not that bad after all. Which memory and bus speed did Elbox's Dragon run? I'm thinking DDR2 RAM should speed up things. ATA controller is also built in V4e core.

Re-werite an OS that hasn't been finished yet to run on a CPU thats only partially compatible. Then require that apps be re-compiled for the new CPU or run in an emulation mode that provides much lower performance. The entire idea sounds kind of painful.
And how are you going to implement the rest of the chipset?  Is this going to be an accelerator card or a complete new computer?

Yes the Natami will be fairly expensive, but hopfully it will offer a good level of compatibility. Your idea doesn't offer much compatibility at all.
Personally, I'll stick with NG OS' and hope for better emulation as they progress.

[Iggy]

As you've pointed out, it is a hobby so I'm not going to discourage you.
If you do explore using a Coldfire CPU, hopefully you can keep us informed as to your progress.

[Iggy]

I've noticed FIDO but I haven't considered it. Do you think one could use a dual CPU configuration and possibly use FIDO to execute legacy 68K apps and CF to run patched AROS68K? I'd like to keep CF on board so to be able to use faster DDR memory and it would offer greater speed in native CF applications(and those that would be cross-compatible between 68K and CF).


also, feel free to name any other 68K and 6502 compatible CPUs as I'm still evaluating all options

That might make more sense. FIDO has an operating speed of 66Mhz. Considering that it is a 68000 and that a 50Mhz 68060 would probably outperform it, adding a Coldfire processor to either makes some sense.
The real trick would be getting AROS to use both processors. AmigaOS and its derivitives have never sucessfully used more than one processor.

[Iggy]

So, to summarize, we're talking about a V4 Coldfire with its own memory used in an accelerator installed on legacy Amigas running AROS68K (suitably modied to run on a Coldfire processor). Is this correct?

[Iggy]

In a word, yes.

Usage? Hobby.

Why make it? To provide a hardware solution for AROS 68K. Running AROS68K natively on a V4e Coldfire would provide a noticeable improvement over even the fastest 680x0. Only apps affected by 68K/CF incompatibility would be affected and would run at 030 or 040. But, with a max of 4 GB DDR RAM, a PCI graphics card(Matrox still makes new PCI cards and they'd be willing to provide documentation, but alternatively older Radeon or GeForce cards could be possibly used, especially if supported under Gallium) and fast disk would it matter much? I think there is no 68K application that would not run EASILY on such a configuration.

Elbox Dragon was supposed to be priced at 350 euros, according to their website.

I would really like to know more about what Elbox was planning. I just downloaded some technical data from Freescale and I'm having trouble seeing how a MCF5474 could be implemented in an accelerator. The Coldfire CPU has some common instructions it shares with the 68K but the interfaces are radically different. The MCF5474 is a much more integrated product. Not quite an Soc but close.

[Iggy]

There are some pictures of Dragon here from 2006...

http://tdolphin.org/amikrak/amizaduszki2006.php

I wonder if they'd be willing to sell the design  if it still exists?

Interesting! Looks like it relies on RTG. What, if any, Amiga legacy components are supported?

[Iggy]

I'm trying to find some more info about it...

I re-examined the photos you referenced and looked at Elbox's website to gather further information.
The base for the 1200 Dragon system is a replacement bus board similar to their Mediator but with a processor slot and an AGP video slot. An Lattice FPGA is visible on the bus board.
I assume that connection to a 1200 motherboard is similar to a Mediator 1200.
There is little visble on the CPU card except for the two DDR memory slots visble on the back of the CPU card.
The Coldfire processor  mentioned is the MCF5475. This is slightly different than the MCF5474 I've seen mentioned in relation to the Atari Coldfire Project.
One thing that becomes apparent is that the Coldfire's main interface with other components is via the PCI bus.
This approach (which suits the Coldfire's inferface) is not similar to other 68K based accelerators.
In order to use this processor a heavily customized OS would be needed.
I'm not sure why some of the photos show AmigaOS 4.0 splash screens. To the best of my knowledge AOS4 makes no use of an Amiga's 68K processor (running all code on the PPC processor).

If I can dig up any further details I'll post them.

Jim

Edit - Looking at the design of this processor, I don't see how it could be incorporated into an Amiga as code that directly accesses legacy hardware locations would not function correctly.

[Iggy]

I was juts looking at some of the V5 Coldfires that can be found in certain printers...

They go as high as 540 MHz!!! Even emulated, any 68K apps would FLY! Man, this would be a killer CPU to test AROS on. I wonder is there any way to get these chips but not having to deal with Freescale directly?

What printers are they found in and are the processors socketed or soldered directly to the boards>

[Iggy]

Some more info on V5e...

supports DDR2 RAM(V4e only DDR)
has onboard Wi-Fi on some models(correction - can come with W-Fi interface, needs ZigBee Wi-Fi board).

I'll try to get an example through HP channels(or some other vendors).

 Yes, but is it a BGA that is soldered directly to the board? We would have a lot of trouble salvaging those.

[Iggy]

I don't know, but I know a person who works with printers and I have asked him to find out if I could buy V5e through him(since he services printers and has contacts at various companies), along with any documentation/developer's tools. I also asked about motherboards... I should have answers in a day or two.

I think a 540 MHz V5e would be great to have.
That's probably more then enough for DVD playback and encoding.

From a technical aspect, its interesting, but if it requires to much work to get 68K code running I'm wondering if there's an advantage over MorphOS' JIT interpreter.

[Iggy]

Well, this would be a fun project aimed entirely at classic hardware and aimed for AROS68K only.

But... if it's 540 MHz passive cooling, then greater speeds might be possible with fan cooling. Also, it supports DDR2 RAM(more then 4 GB RAM is possivble with V5e)... this would be a pretty decent computer in any way. Add AGP graphics and it'd be great for upgrading 68K systems(though I suspect it would have to be a towered system for it to fit). Don't know, maybe a standalone board which would fit inside any Amiga + FPGA makes more sense?

V5e is an enhanced V5e core. Unfortunately, there's very, very little info about these even on Freescale's webpage. That's why I asked about documentation. Even so, a V5e is fully superscalar and could be fully pipelined. At 540 MHz, it should run above 060 speeds even in 68K emulation mode.

I appreciate your enthusiasm, and I'd urge you to explore this idea fully.
My only reservation, as I've sort of stated before, is that if emulation is required then solutions we already have may work just as well (or better).

[Iggy]

Again, this would not be directed at AmigaOS, but AROS68K. I wouldn't even be talking about this for Os 3.x because it's too much of a hassle for not much speed up.
Emulation layer would be needed for those apps/games that call 68K specific instruction that are absent from CF. With the V5e core, even those apps would probably run far faster then on real 68060. On V4e core, they would run somewhere between 030 and 040 speeds.
For apps compiled on CF and newly written apps, they would run completely native on CF and at full speed.

But the key point here is that 68060 costs a LOT of money, while CFs are dirt cheap. And they enable modern peripherals, DDR RAM, ATA, even Wi-Fi.

This is only an idea currently.

Yes, Coldfire is cheap and it would add a PCI interface and USB ports (as well as some other feature I haven't reviewed yet). The emulation (or JIT interpretation) would have to function on all 68K code and not just for missing instructions, but also for instructions that operate differently (on Coldtfire than the 68K).
It might be hard to get the V5s, so don't give up on the V4s yet.
I'd love to see this combined with a FPGA emulating the Amiga chipset.

[Iggy]

Me too... I'd prefer it to be an acc. card(towered 1200 or 4000) because of price, but if it is not to be for this or that reason, a standalone motherboard with FPGA could be made.

But I'd like to avoid a standalone option, because it would be pricier, competing with NATAMI and while it would probably be somewhat cheaper, we do not need 2 very similar products with a similar price on this very small market.

Actually, it would be a fourth system in a limited market. First the Minimig, then the FPGA Arcade, then the Natami, and finally this system.
So you're right, it would be better to keep the price down (by avoiding a FPGA).

[Iggy]

Or RISC vs CISC lol

Acorn Archimedes had the same issue, and people all said 'whatever' 'what happens when you need to divide?'

Truth was when you all paid 1000s for crapp 7mhz A2000s and then played a 16 colour game called Virus at 10-15FPS the Archimedes did it in 256 colours and 30+ FPS in 1987

RISC is better, and a Coldfire v4 + AROS specific kernal recompile + UAE = Rocket Ranger running 100%.

Why do people have to make it so difficult. AROS Coldfire for legal Amiga apps written in guidelines, AROS+UAE for legacy/games stuff.

It's not like MorphOS does it any better, or OS4 come to that At least Coldfire is dirt cheap unlike way OTT priced PPC boards to run OS4/MOS

Actually, if you look at the benchmarks, MorphOS does do better in a lot of areas. X86 definitely has more horsepower to run 68K emulation, but in most other areas MorphOS has an edge.

http://www.lukysoft.cz/?page=benchmarks

And since Coldfire is a CISC, I suspect that RISCs like ARM and PPC might outperform it.
PPCs are expensive, but ARM and Coldfire are not so we'll just have to see.

[Iggy]

I wouldn't consider Minimig or FPGA arcade as competitors to Natami or my proposed CF machine. Sure, there is some common ground between them, but my idea is more of a next-gen 68K like Natami.

If I cannot get this my idea for under 400-500 euros, I will not do it. Primarily because then, IMHO, it becomes too expensive to be called hobby(even so, I'm sure some people might still want to buy a machine like that) and it would be too close to natami to justify it for me personally.

Personally, I'd hope for an even lower price as 400-500 euros strikes me as a little high.
I could see that if it did incorporate a small FPGA, but if not I'd hope to see it for as little as half that figure.