AROS68K and the Freescale Coldfire CPU

[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.

[Iggy]

Atari Coldfire is 599 euros(they have a expensive FPGA oboard), so you are right...
My goal would 300-350... But I have insufficient info to base that on any real life data. Especially the V5e price.

If the only way to get V5s is to salvage them and have the processors re-balled this could get expensive.
The V4 still might be an easier to obtain option.

[Iggy]

MorphOS is no better than OS4/AROS in the context of my post. ALL use UAE to run legacy stuff like Rocket Ranger.

So OS + Emulator requirement is present on all 3 for REAL Amiga functionality.

My point about ARM or RISC was the removal of instructions to streamline the chip performance is exactly what ARM v1 did in 85 prototype and 87 retail machines. 400 MIPS is more than enough to emulate OCS or ECS and if you are writing a specific version of AROS for Coldfire and using something like Starscream to emulate 68000 then it is a non-issue.

We need to get off PoS PPC hardware that is overpriced AND underpowered. There is only an issue with getting KS/WB to run on Coldfire, if you are writing an OS version of AROS for it there is no issue whatsover.

You're mistaken if you think we in any way disagree. I like my current PPC system because it is low cost and while I look forward to G5 Mac support I can't really justify the cost of new PPC hardware.
ARM would definitely be an improvement. They've already developed 2Ghz ARM processors, the current A9s should be good for 2.5Ghz, and I expect to see higher performance out of later introductions like Nvidia's Denver Project.

And yes, X86 emulation does seem to work fine. If you've got legacy apps its hard to argue with the performance advantage. I just pointed out those benchmarks because they point out pretty clearly that MorphOS does a fairly good job at 2D and other non CPU related tasks.
In the last few months I've been a pretty vocal advocate of moving to ARM.

Now Coldfire, the main thing that worries me (besides compatibility i ssues) is that its getting rather old and the fastest available version is the 266Mhz V4. That's a solid improvement over a 50Mhz 68060, but I'm still not sure it makes sense when compared to ARM or X86 (both of which can outperform this).

Anyway, lets see if there is some way to obtain V5es. If so (even in small quantities) this could offer the additional performance that would help justify this project.

[Iggy]

@WolfToTheMoon

The only reasonable way to start is to get hold of a CF V4 developer board and get AROS running on that first, _then_ you can come back and talk about doing all the other things you've mentioned.

That would be a valid idea, but I can't find one on Freescale's site. Do you know of any?

BTW- If you can get to France, these two courses look interesting.

http://www.mvd-fpga.com/training/en/files/formations003831A.pdf

http://www.mvd-fpga.com/training/en/files/formations003382A.pdf

Correction -First development board found
$850 for evaluation board for MCF547X Coldfire Microprocessor

http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=M5475EVB&fsrch=1&sr=1

Freescales direct sales system erroneously pairs this up with a PPC processor that wouldn't be applicable for this board.
I still have to find out if this board comes with a processor (but it seems likely).

The MCF54455 would probably be a better processor to use. I haven't found an evaluation board fort this though.

http://cache.freescale.com/files/32bit/doc/data_sheet/MCF54455.pdf

I can get samples of the 266Mhz MCF54455 from Freescale, but starting a project with these is daunting.

OK, evaluation board for the MCF54455 (also $850)

http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=M54455EVB&fsrch=1&sr=2

[Iggy]

It can be done, how ever its a matter of money.
But what about the Dragonball?? There you can have everything in one unit. Its old, but still..

For 68k and coldfire compatibility there is this http://www.microapl.co.uk/Porting/ColdFire/cf68klib.html

Nice reference, interesting company. Although I'm still curious as to what a 68340 is (in the chart in their FAQ).
Looks like Coldfire could be used to work with some 68000 code, but the interpreter still doesn't handle instructions that operate differently on Coldfire.

BTW - Dragonball is slowww..
         And is EOL (not available).

[Iggy]

ColdFire CPUs are dirt cheap... in fact, you could probably sell an entire acc board with a V4e Coldfire, DDR RAM and PCI GPU for the price of one 68060 CPU.

Yes Coldfires are cheap. About a quarter the price of a 68060, and I can get '060 50s for under $50. I don't think the accelerator boards would be quite as inexpensive as you've estimated, but they should undercut 68K accelerators and would be a lot lower than PPCs.

[Iggy]

Run th CF68Klib in supervisormode, then most kind of 68k SW/OS should be possible to run on af CF cpu

The problem with CF68Klib, if you check the documentation, is that even in supervisor mode it doesn't trap instructions that run differently on the Coldfire than they do on the 68K.
I'm sure there's a way around this, but while CF68Klib looks promising, it may not be the only answer.

[Iggy]

...Note that this is not foolproof. Self modifying code etc. or code that intentionally jump into the middle of an instruction could still cause trouble and is much harder to deal with....

Man, I'd almost forgotten about that practice (self modifying code). Anyone resorting to that should be bitch slapped.

The JIT could be very fast, as for any instructions deemed "safe" it'd just need to recognize them and move on to the next instruction, and recognizing them could be done with a very small, compact decoder since it could discard large groups of instructions as safe with a few simple bit masks.

Having seen what the MorphOS team managed to do with JIT for 68K code running on PPCs I'd have say you've got a point. Since many of the instructions would not require modification, this should work fairly quickly.

[Iggy]

I have some info on the V5e...

The guy I contacted informed me that the entire motherboard from the HP laserJet that contains the V5e @ 540 MHz can be bought for about 500ish $ thru his service. I'm still trying to find info on whether I could get any V5e documentation.

Well, at least we know they're available. Removing them from the boards and re-using them is nightmarish task, but not impossible. And the printers may be available used, refurbish, or broken allowing salvage of V5es from those sources.

Although I wouldn't discount the idea of using V4s just yet. They're available, low cost, and run at up to 266Mhz. As has been pointed out, JIT translation of 68K instructions to Coldfire should be aided by the similarities in the instruction sets.

[Iggy]

here are some becnhmarks... a V4e Coldfire running at 200 MHz on a MCF5484 evaluation board vs CT60-100-25(68060 @ 100 MHz!) and Hades 060 atari clones.


http://img402.imageshack.us/img402/3604/kronos2.jpg





More info can be found HERE


As you can see, the Coldfire V4e did rather good in most tests.

I was actually surprised to see the 68060s doing as well as they did in comparison. That early Coldari posting is fascinating. Thanks..