MiniMig + PowerPC = OS4 Hardware for all

[AJCopland]

little wrote:
Nowadays MIPS is barely a memory and for quite some time sony has not used that architecture in anything new.

...except for the PSP which is MIPS32 based with matrix/vector co-processing hardware. Oh and the PS2. Mips is quite a nice architecture to work with actually. Not the best but nice and simple to get used to I found.

Andy

EDIT: darned typos...

[downix]

AJCopland wrote:

little wrote:
Nowadays MIPS is barely a memory and for quite some time sony has not used that architecture in anything new.

...except for the PSP which is MIPS32 based with matrix/vector co-processing hardware. Oh and the PS2. Mips is quite a nice architecture to work with actually. Not the best but nice and simple to get used to I found.

Andy

EDIT: darned typos...

The original PS3 had a MIPS chip in there as well IIRC.  Not as the main CPU, mind you, but in a peripheral fashion.

[AJCopland]

The launch versions of Japanese and US PS3s, but not the European and UK, ones had something in there. It was either the MIPS cpu or the EE, not sure which. Either way somethings in there much like the IOP in the PS2 to provide hardware based backwards compatibility.

Unlike the IOP though you can't write code for it using the Sony APIs so it can't be used to offload anything. Shame really as the IOP was very handy for that kind of offloading work.

Andy

downix wrote:
The original PS3 had a MIPS chip in there as well IIRC.  Not as the main CPU, mind you, but in a peripheral fashion.

[Crumb]

[AROS...]

It already runs hosted. Getting it native should not be too difficult now that AROS handles 64-bit.

AROS runs hosted on SPARC??? are you sure? The PPC port took some work to leave it at the same level than x86. Now that AROS runs on various CPUs and the 64bit port is improving, a SPARC port would probably be easier. I know some code was written to support SPARC, but AFAIK it doesn't run on SPARC yet.

Anyway feel free to prove me wrong... I wouldn't mind watching a screenshot of AROS running hosted on your SPARC machine  :-)

[Skyraker]

Speaking of Patents... i'm sure I read recently that Gateway are about to be bought out / taken over.

I'll go find out some more.

** Bloody interesting thread btw **

*Edit* Gateway now belongs to Acer. Can we have our patents back please?

[freqmax]

@Skyraker:
They seem to sit on the patents until they rot :-)

@downix:
"add registers to the setup without having to remap" what do you mean by remap?
How does these custom "cpus" know when to run or halt?

[downix]

freqmax wrote:
@downix:
"add registers to the setup without having to remap" what do you mean by remap?
How does these custom "cpus" know when to run or halt?

Well, if I insert a bank of registers, it has to fit somewhere into the memory map of the system.  But, 8086 dictates a lot about where you are allowed to map these banks into a system, how many you can have, the size, etc.  To work around it is a headache.
And typically custom co-processors are started by the main CPU, and flag when they're finished through an interrupt.  But, in some cases, they can keep going, fetching the next set of work without needing CPU guidence, through a dedicated co-processing element such as a dedicated "stack-start" register, or other methods.  Lots of ways you can do it.

and @Crumb
Just looks like AROS on Linux, but I can grab a shot for you in a bit once I recompile it.

[little]

A basic (SPARC CPU) entry-level can be had for less than $20

What about giving the name of this CPU so a real comparision between this and other CPUs in the same price level can be achieved?

BTW, The PSP is basically a scaled down version of the PS2, which was launched in 2000, in computer years that is a lifetime ago :-P

[freqmax]

Speaking of PS3.. a Cell cpu wouldn't be too bad :-D

@downix:
What do you mean by "bank of registers" ..?

In the case of Amiga (or even Sun). The co-cpus are started by the main cpu and then continue until told to stop?, or do they start at system boot directly (like the main cpu) ..?

[downix]

little wrote:

A basic (SPARC CPU) entry-level can be had for less than $20

What about giving the name of this CPU so a real comparision between this and other CPUs in the same price level can be achieved?

BTW, The PSP is basically a scaled down version of the PS2, which was launched in 2000, in computer years that is a lifetime ago :-P

That would be the one I mentioned earlier, the S1.  It's a bit too new for real detail on specs, but as the core is similar to the UltraSPARC II, I'd compare it to that.  Which does mean that it's performance is comparable with, say an AMD Athlon 800Mhz, but while consuming 1/5th the wattage.  A lot faster than the SoC PowerPC's we're currently looking at.
In addition, there is also the MicroSPARC, which retails for $15, but it is a 32-bit SPARC, not a 64-bit, so not a very good comparison.  Also the PicoSPARC, same issue.  The Geisler LeonSPARC can also be had for this price, but again, 32-bits.  The S1 and II are the two entry-level 64-bit CPU's at this time.  I don't know Sun's pricing on the II atm.

[downix]

@downix:
What do you mean by "bank of registers" ..?

In the case of Amiga (or even Sun). The co-cpus are started by the main cpu and then continue until told to stop?, or do they start at system boot directly (like the main cpu) ..?

Well, in some setups (like the Amigas) registers can be mapped just like memory, so I typically call them the same way I would a memory bank.
And no, the CPU starts to co-pro (hence why it's a co-pro and not a full processor).  How it starts them depends on the CPU and co-pro.  In the Amiga's case, the CPU just had to write the starting address to the coppers control register, and that started it running.

[RW222]

Hmmm getting a headache trying to follow this thread, apologies if this has been addressed elsewhere...

I think, it's a "game of two halves", we need to boil it down to
i)What is the minimum Amiga specific hardware necessary to act as a classic "bootloader"?
ii) What is the minimum Amiga specific hardware necessary to run it after it's gone over to PPC mode? i.e. how necessary are custom chips at this point?

Because it seems like a whole lot easier ballgame if minimig hardware would not have to integrate with the PPC hardware beyond being able to hand over and bootstrap it.

So, problems of integration with the host machine may be simplified if the host machine does not have to have access to any of the custom hardware on a minimig board.

So, if all that's really necessary to run the PPC part is gfx we have drivers for, sound we have drivers for, standardish ATA interface, standardish network card- then we don't need much in the way of hardware emulated classic hardware.

So, if we rethink the minimig on PCI proposition as mostly an independant machine on a card, that does not integrate with the host machine beyond resetting it and bootstrapping it with the PPC code, then it might be an easier task.

Then we could use PPC/PCI boards, with a minimig to boot them, and that's all it needs to do.

IF we do need some classic hardware to run in PPC mode, a seperate implementation of it in FCPGA accessible only from the host side could be the answer. It could be derived from minimig, but it would essentially be functionally independant from the minimig bootloader part. It's a dirty solution, one and a half amigas on a PCI card, but if it will work....

I don't see why though, even if you have the minimig as a bootloader that you couldn't have it independantly functional as a classic mode machine solely for old games and such, with only the 680x0 CPU on board and the emulated chipset available for use. (i.e. the rest of the PPC machine's hardware is unavailable) but hopefully sharing compatible drives.

You'd have a kind of dual boot machine, one option would boot to classic, just the minimig and a classic 68k OS, the other option would be to use it to bootload OS4 on the PPC hardware.

So break it down into, i) what the 68K bootloader side needs to "see" for it to work, implement it in minimig. ii)what the PPC side needs to "see" for it to work, implement it with Amiga compatible PCI cards and if necessary FPGA emulation.

It would seem that i and ii would not have to be fully integrated. You'd lose compatibility with stuff that was written to co-process on PPC from a 68k OS though, but it sounds like it wouldn't work on OS4 anyway. But if you have that requirement you already have a PPC accelerator and don't need this hardware, and probably won't want to run 0S4 on it if you're dependant on that functionality.


Anyhoo, those are my crazy mixed up thoughts on it FWIW...

[AJCopland]

On-topic.
I thought there were still 603e and 604e based cores used in PowerPC cpus from Freescale. They might have been tweaked somewhat for process shrinks and cost reductions but they may well be fully compatible with all of the PowerUP and Warp stuff that exists.

If we're willing to settle for a lower end part at about 400Mhz or so then an MPC5200 would probably suit our needs.

The only problem with all of this seems to be the cost. All of the PPC board that i've seen being touted by people are really damned expensive because they use 10 layer board and incorporate everything including the kitchen sink!

So the real question is: Is it possible to do a basic PPC board with soldered on (DDR?) SD-RAM, the FGPA (500k gates+) and the MiniMigs current connectors for less than £200?

Or would it make more sense for us all to increase AmigaKits sales a little and order the Efika whilst turning the MiniMig into a PCI card for it?

Opinions on a postcard please :-D

Sorry for wandering a little off-topic everyone but:

little wrote:
BTW, The PSP is basically a scaled down version of the PS2, which was launched in 2000, in computer years that is a lifetime ago :-P

This is a myth that was caused by Sony stating that the performance of the PSP lay somewhere between a PSone and a PS2. The three of them are markedly different architectures and don't even use the same versions of the MIPS cpus.

They're all MIPS but different variants and with very different co-processors. I know this because I've worked on three multi-platform titles that all covered the PSP and PS2 ;-)

Andy

[downix]

AJCopland wrote:

So the real question is: Is it possible to do a basic PPC board with soldered on (DDR?) SD-RAM, the FGPA (500k gates+) and the MiniMigs current connectors for less than £200?
Andy

Not realistically, no.

[AJCopland]

downix wrote:
Not realistically, no.

:lol: well its good to get that out of the way at least! How come though? I realise that the examples I'm thinking of are commercial ones like the LinkStation or some set-top boxes, I guess they have ecomony of scale on their side.

How about the boards for PPC then? Is it feasible for us to do homebrew boards with only two layers that support a PPC chip or are they going to require more as a minimum? I ask since it gets more expensive for people to make N-layer boards doesn't it and anymore than two is instantly outside the scope of etching our own.

[downix]

AJCopland wrote:

downix wrote:
Not realistically, no.

:lol: well its good to get that out of the way at least! How come though? I realise that the examples I'm thinking of are commercial ones like the LinkStation or some set-top boxes, I guess they have ecomony of scale on their side.

How about the boards for PPC then? Is it feasible for us to do homebrew boards with only two layers that support a PPC chip or are they going to require more as a minimum? I ask since it gets more expensive for people to make N-layer boards doesn't it and anymore than two is instantly outside the scope of etching our own.

The sheer number of pins and the short distances that they can run makes 2-layers very difficult to manage.  The best solution would be to buy a chip with a PPC core already included, but they start at over $800 in volume.  We're in between a rock and a hard place here, sadly.  I would sooner recommend sticking it out with the original 68000 and keeping the price reasonable than take such a risk at this time.