Motorola 68060 FPGA replacement module (idea)

[wawrzon]

actually someone is actively working on an a600 fpga accelerator:

http://www.natami.net/knowledge.php?b=6¬e=32232&x=7

http://www.a1k.org/forum/showthread.php?p=589135#post589135

he may not be very experienced, but he is motivated seems to learn quickly and may require all assistance and support from experienced hardware experts (preferably without sarcastic remarks).

it seems to be a rule that the experienced users dont start such projects for whatever reason, maybe bored with it at work or maybe knowing how much effort it is. on the other hand there are those willing newbies. being stubborn and treated right, like the guy recreating thylacine-usb also on a1k, they actually deliver some results. so maybe just try to support them as much as possible.

what concerns coldfire if there were free open source modifyable cores one might adopt changes granting backwards 68k compatibility. i guess natami team might have such a chance at some point as they ve been provided coldfire dev boards by bbrv at some point.  but there are no open cf cores as far as i see, and its unlikely freescale will reveal its designs, so this isnt an opportunity.

[wawrzon]

perhaps if focusing efforts of all involved the (intelectual and work) investments fore each one could be minimized while solutions may be reached easier, as it happens with open source efforts, such as aros. when the common (technical) goal has been reached the actual technic can anyway only be provided by those who are able to handle it. therefore supporting the common goal might be benefitial for all.

on the other hand c64 hardware market except it is bigger is probably more easy to staisfy with simpler solutions.

[wawrzon]

Developers may want make the most comatible solution, others the fastest with most bells and whistles which ofcourse ends up with that you loose the starting point.

Some have different coding styles. Or just use different schematics CAD. It might be more fun to make new than to integrate with existing creations. Some stuff just requires a heavy start like Kickstart+Workbench and thus require a dedicated work like the one undertaken by AROS-m68k.
etc..

There are reasons why efforts diverge.

all that has to be overcome in an software open source community projest as well. everything an  individual has to understand about it that together we can get further and faster than each on his own. all that costs some drwabacks like making appointments and coordinating the effort to certain extent but the gain is worth the cost usually. otherwise we wouldnt have any industry, hell we would not have a civilisation. it just a basic social thing.

that said im not trying to insist on anything just pointing out stuff to consider. look at natami, where an isolated one man project tends to end after all that effort. nothing has been gained, save for thomas himself. maybe even him considers it wasted time now. if it was open someone else might have followed up..

[wawrzon]

He has his own site: http://www.majsta.com/

Seems several FPGAs had to give their life to that project due to soldering technique. But he seems on track now.

i said he may not be experienced but stubborn. thats valuable too. if it was common effort someone else could solder for him..

[wawrzon]

wow?! so where we start. actually we would have to agree on hardware to use. x86 is one option. arm is another, perhaps better because of endianness and because its easier to find contemporary module witha single core cpu. i think the board would have to be assembled of a prefabricated module and a glue bridgeboard.

[wawrzon]

i think a tiny industrial module is a better choice than a bga cpu because it provides chipset, ram and doesnt require soldering. it should be singlecore too i guess, emulation doesnt need multiple cpus.

btw here is a corresponding thread on a1k, some people such as ratte, newamigauser, jens schoenfeld (paradroid) considering 68k, fpga and x86 emu accelerator as option:
http://www.a1k.org/forum/showthread.php?t=35374&page=11

[wawrzon]

I think it's unrealistic to do this in an 68060 replacement module, but an A1200 accelerator design would be awesome.

or an 030slot board for big box amigas. the glueboard could provide both variants.

[wawrzon]

And x86 need lot's of peripherals to run.

therefore im hammering on using an available module. prefferably one available in longer therm. anyway its the easiest way to approach.
thats what tobiflex did
thats how ratte tried to approach (http://www.a1k.org/forum/showthread.php?t=6745&highlight=ratte+holzbrett)
thats what shadowfire and otheres had in mind apparently.
this is the easiest way to proceed i guess. none here will be able to develop x86 accelerator from the scratch together with mem controller and all periferials people wish.

[wawrzon]

Indeed!

Though I personally think that what might be more fun is to have the x86 interface directly with an FPGA large enought to take the MiniMig core, and bring out the Amiga compatible I/O (as the MiniMig does)

sounds even better perhaps, a x86 cpu module for fpgaarcade?? there would be no doubt about interface, and the original amigas might stay what they are, which is what im fine with.

[wawrzon]

so all you need is decelerator board? lets focus on something else.

[wawrzon]

i'm happy to see his thing booting at all

me too!

 i don't understand the slowness
 

it must be the bus. has been advised not to take one cycle without going into detail. seems its hard to get honest help. ofr it might be signals on the self made board..

anyway i like his stuborness, as said.

[wawrzon]

How about this for a crazy idea, an accelerator with an Arm CPU and an FPGA, the FPGA can function as a 68k CPU if set up as such, so it could run like the PPC accelerator boards. BUT you install AROS for ARM ROM chips and use the Arm as the main CPU, and allow the FPGA to be reconfigured by the Arm chip, so then you could develop your 68k core "live", and install updates through software.

i dont get it, but sounds like another hybrid idea, aros arm system with 68k apps. imho anything like warpos solution is a waste of time. we shouldnt create another split/branch with the need of dedicated binaries, and we shouldnt follow feature creap strategy. lets have simple 68k accel, as simple as it gets, no strange ideas. lets treat 68k as virtual common platform/denominator, then we will maybe have chance to actually achieve something one day.

lets start discussing wierd complicated ideas and we can have fun threadthat will follow in natami footsteps, to nowhere.

[wawrzon]

But we already have AROS for Arm.

sort of. actually hosted. its being worked on native version especially for pi.

Dual CPU PPC accelerators already exist so we have experience from that.

we, means who? the documantation of ppc boards is closed source owned by dce germany, its outdated and it is not going to be given to us except for multiple ten thousands of euro as it has been revealed. also there is none who would realistically build such a ppc board. jens schoenfeld outright refuses to have anything to do with unreliable ppc architecture as he considers it. such an hybrid board is very complicated and expensive in fabrication, Many layers, bga, and requires special softwware (warpos like) which is even more complicated. besides an approach like that already exists with ultimateppc. lets see what will come out of it.

the hybrid ppc boards were a sick stunt to start with. overpriced, overcomplicated, creating a split in community as they need own binaries, non reliable enough, with os4 its even crippier, when you have an ecpensive 68k cpu onboard surrounded by support chips not even being used. i see no advantage of such design even with an arm in place of ppc. please dont repeat past failures.

as for the rest, we actually have the software in question whether its the 68k emu or 68k fpga core already, or what do you mean. what we need it hardware to interface it to amiga, be it fpga or an asic cpu interface. im not an expert but i think this is much easier to achieve. since it has been now proven multiple times that fpga accelerator basically works. it can be improved on that.

and also if you want just an arm system with hosted 68k emu why not just hack an x86 or an arm board directly into amiga housing. with janusuae you will have semi transparent 68k emulation i guess. if this is what satisfies you, i dont see what might stop you, everything is at hand, no need to develop anything, you can start sawing your case right away.

[wawrzon]

@jimdrew:
i thought there is separate data and instruction bus, that can be handled separately. data will always need to be swapped i guess, where is the problem?

also, what does your 040 emu actually provides? does it support fpu and mmu? i guess it would be quite important and at the same time pretty complicated and expensive to have in a pure fpga. this is another argument in favour of x86. winuae contains cpu + fpu emulation with partial mmu emulation, the complete mmu support being merged in by toni right now.

[wawrzon]

Well I don't want to saw my case up for one thing... I'm not suggesting using PPC just pointing out that dual CPU has been made to work. I've never owned one, though, so I can't say how well it works.

i have one. i always refused one but got it beginning of this millenium, and can confirm that its nothing great. the best part is fast scsi controller. i can dispose of ppc, that can only be taken advantage of the specially precompiled code. all the usual (68k) stuff runs as usual on the 68k processor with its usual speed. so its just okay for what it should be.

Accelerators have an FPGA on board anyway to handle various bus signals, could just be a case of replacing it with a bigger one, and an interface to allow the firmware to be updated from software. FPGA accelerator basically works but there is a barrier to community development of the core(s). Plus people could create custom cores, which could produce some interesting projects. I'd like to develop my own core but I don't have the means to produce hardware.

Arm chip need not be expensive.

im sure its not just as simple as glueing another fpga to an existing design if there was one at disposal to start with. look how much effort has been put into minimig, fpgaarcade or natami hardware. there are several fpga aware people around the scene yet except those little else is available to us. lets do not underestimate the hardware development effort and try to keep it as simple as possible on this side. a hybrid board is under these circuumstanced surely not the best approach, except there is one already in development:
http://ultimateppc.nl/