Author Topic: Super Amiga Hobby Project (Just a fantasy ATM) (Read 3333 times)

MskoDestny · « **on:** July 12, 2005, 04:34:25 PM »

Someone recently sent me a link to a low-cost Spartan 3 (an FPGA) dev board and it revived an idea I had for a hobby project. No idea whether or not I'll attempt it (or if I could complete it if I tried), but I think it's a fun idea to dream about.

Basically it would be a Coldfire V4e based computer with a mostly AGA compatible chipset and modern connectivity (PCI, USB, Ethernet). The AGA-like stuff would be implemented on FPGA and would support the classic modes and sound formats, but would also have updated modes for things like 24-bit color and 16-bit 5.1(6) channel sound. Nothing too fancy like 3D acceleration or a sound DSP, though I suppose with a PCI card and appropriate drivers you could get those as well.

Ideally it would be able to run Amiga OS 3.X (ROMs and install disks would probably have to be provided by the user) with the help of that 68K emulation and a new 680XX.library and AROS (obviously the Amiga port would have to be revived).

Personally, I think this would be really cool. It would retain the classic hardware that helped make the Amiga so cool, but would also bring the machine forward enough to be useful for lightweight computer tasks. Obviously it would be a rather foolish commercial venture, but I see this as more of a hobby project than anything.

So I guess the question is, in the unlikely event that I actually do this, would anyone buy one and how cheap would it have to be.

x56h34 · « **Reply #1 on:** July 12, 2005, 04:41:01 PM »

Sure, it sounds interesting, but what about the legal issues in regards to this venture? Would there be a need for some sort of a license?

pixie · « **Reply #2 on:** July 12, 2005, 04:43:48 PM »

150€? Well, for this Project you could try seek AROS, as they might allow you to avoid legal issues while having a full AmigaOS(like system)

x56h34 · « **Reply #3 on:** July 12, 2005, 04:46:18 PM »

I'm just wondering if the chipset itself would be legal? Like if he were to create AGA compatible FPGA replacements... ?

MskoDestny · « **Reply #4 on:** July 12, 2005, 05:25:19 PM »

In theory patents could be an issue, but I seem to remember someone saying that the patents on the chipset have since expired. It's also possible the design would end up being different enough that it wouldn't be considered infringement. My friend's brother is a patent lawyer so in the unlikely event this goes anywhere I could ask him for advice.

As for Amiga OS copyrights, if I bundled it at all I would buy existing legitimate ROMs and disks or would see if Amiga Inc. would be willing to license it (I kind of doubt it, but if they're desparate for cash...).

I doubt I could do it for 150 euros. In low quantities (40+) the 266MHz V4e chips cost around $40 US. An appropriate FPGA would probably be in the neighborhood of $50 (not really sure on this one, I haven't done any FPGA work, just CPLDs so I'm not sure how big of an FPGA this will need). Add in board manufacturing and I might be able to sell one for $300, but that's just a guess.

JoannaK · « **Reply #5 on:** July 12, 2005, 05:56:30 PM »

You could save a lot money/headache by using Soft-core 68K CPU fitted directly inside spartan fpga. It'll be fast enough and have a lot better compatibility with old code than Coldfires are able.

IIRC there may well be one suitable at www.opencores.org

bloodline · « **Reply #6 on:** July 12, 2005, 06:13:57 PM »

Quote

x56h34 wrote:
I'm just wondering if the chipset itself would be legal? Like if he were to create AGA compatible FPGA replacements... ?

You can only patent implementations, if he designes his own AGA compatible chip, he does not need to worry about patents any more than the UAE people do :-)

I like the idea though :-D

bloodline · « **Reply #7 on:** July 12, 2005, 06:18:13 PM »

Quote

JoannaK wrote:
You could save a lot money/headache by using Soft-core 68K CPU fitted directly inside spartan fpga. It'll be fast enough and have a lot better compatibility with old code than Coldfires are able.

IIRC there may well be one suitable at www.opencores.org

Personally, I would base the whole thing around an XScale CPU (With a 68K Jit emualtor) with a CPLD/FPGA (Whatever is cheapest) to emulate the AGA registers/features but with the GFX and audio output being directed to standard off-the-shelf video and audio parts.

MskoDestny · « **Reply #8 on:** July 12, 2005, 06:42:54 PM »

Depending on how many gates/cells it would require a Soft-core 68K might not be a bad idea for a compatibility mode, but I don't think it makes much sense for a main CPU. At the speeds I'd likely to be able to get I would probably just be better off with a 40MHz EC030 (~$60 from Digikey). Doesn't look like they have a 68000 at opencores anyway, just a 6800.

For me, the XScale + off-the-shelf solution would be cheating and not really a "real" Amiga anymore. Still, not a bad idea to keep in mind.

I think if I do attempt this I'll start with a Spartan 2 in a PCI form factor (fpga4fun sells a $99 board in this config) and work on AGA compatible video hardware. I could then modify UAE to send video writes to this card for testing. That way I can break down the system into pieces for testing.

JoannaK · « **Reply #9 on:** July 12, 2005, 07:06:03 PM »

I needed to check, it's been some time since I visited that site. See :
http://www.opencores.org/projects.cgi/web/k68/overview
Apparently it's been uploaded about two years ago and has not been debugged since. Ah well, at least it's opensource and I think it could make nice start for project.

MskoDestny · « **Reply #10 on:** July 12, 2005, 07:33:43 PM »

Ah, okay. I didn't see it because I didn't turn off the filter that prevents beta cores from being shown.

It looks like it's relatively small. If I use a large enough Spartan 3 (maybe the 1000 part) and I'm thrifty with the AGA stuff I could probably fit it in. Definately a possibility for a compatability boot mode. If it doesn't fit, I suppose I could make a second core with just a standard AGA or even ECS to save space and just add an option at boot to choose a core.

amiga4001 · « **Reply #11 on:** July 12, 2005, 07:38:40 PM »

If you could keep the price around $300 I would surely buy one from you.
Should also be nice if it would fit in a mini tower or something.
Hope you will work it out.

billt · « **Reply #12 on:** July 12, 2005, 08:38:40 PM »

> I'm just wondering if the chipset itself would be legal?
> Like if he were to create AGA compatible FPGA replacements... ?

That's all the BoXeR was. Too bad that went down the tubes... This sounds like quite a project, I hope you actually get someplace with it.

Doppie1200 · « **Reply #13 on:** July 12, 2005, 10:06:40 PM »

Ive worked on a project like this. Not the programmable logic but on the software side. The problem was simulair to this. The approach we took was like this.

To recreate the exact functionality of exsisting hardware lab proto's were buidt that could interface with the original hardware. For instance; you pop out the device you want to replace. Build a protoboard that connects to the original interface (or directly to the PCB) The protoboard contains glue circuitry and your programmable device. The glue is to cope with electrical incompatibilities between the new decive and the current interface.
You program your new design in your programmable device. When your design is functionally the same and all works as before you advance to the next device. After all devices are redesigned into seperate parts you can take the next step.

Melting your design into one fpga. At this point you can estimate how much of your design will fit into your target device. You could decide to split things in order to be more expandable.

Ofcourse this will require some redesigning because interfaces will change again. At least your functional blocks are correct. You verified them using the existing hardware.

When you have melted the blocks into your target devices, redesigned the PCB (with expandability in mind, and got it all working again you can add nice features to the design.

But I would first of all keep it simple.

A collegue of mine made a drop in replacement for the 6510 CPU this way just for fun. He has been expanding that design to a more modern architecture (he said he got to 68040 comparable performance) but the project is in the ice cabinet now since he has become father recently.

Still, I think these ventures are technically possible, but as a one man project it is probably too much work.

It also requires some cash. When you run into trouble (and you will) you need pretty expensive equipment to measure all the signals you are interested in.

But it is always nice to think about these projects.

Jose · « **Reply #14 on:** July 12, 2005, 10:53:00 PM »

Since you're at it why not finish the AAA chipset instead and make it AGA compatible. Then you could implement it in FPGA in a PCI card so that any future Amiga could have classic compatibility. I think like that would make it much more comercially viable, just look at the Classic Amiga sales on eBay.

Author Topic: Super Amiga Hobby Project (Just a fantasy ATM) (Read 3333 times)

MskoDestny

Super Amiga Hobby Project (Just a fantasy ATM)

x56h34

Re: Super Amiga Hobby Project (Just a fantasy ATM)

pixie

Re: Super Amiga Hobby Project (Just a fantasy ATM)

x56h34

Re: Super Amiga Hobby Project (Just a fantasy ATM)

MskoDestny

Re: Super Amiga Hobby Project (Just a fantasy ATM)

JoannaK

Re: Super Amiga Hobby Project (Just a fantasy ATM)

bloodline

Re: Super Amiga Hobby Project (Just a fantasy ATM)

bloodline

Re: Super Amiga Hobby Project (Just a fantasy ATM)

MskoDestny

Re: Super Amiga Hobby Project (Just a fantasy ATM)

JoannaK

Re: Super Amiga Hobby Project (Just a fantasy ATM)

MskoDestny

Re: Super Amiga Hobby Project (Just a fantasy ATM)

amiga4001

Re: Super Amiga Hobby Project (Just a fantasy ATM)

billt

Re: Super Amiga Hobby Project (Just a fantasy ATM)

Doppie1200

Re: Super Amiga Hobby Project (Just a fantasy ATM)

Jose

Re: Super Amiga Hobby Project (Just a fantasy ATM)