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[Palm]

Has anyone a good technical answer to this:

As the MinMig works great as a A500, is it possible to do the same to the A1200 ? Or is the A1200 so much more complex than the A500, that making it in a FPGA is virtually impossible ?

Just wondering :-)


Espen

[countzero]

it's not impossible, but difficult. but I believe it will be done eventually. there's already a project called NatAmi which progresses very slow (some also regard as vaporware).

[Palm]

Yep. I did see the NatAmi project, but there is not much hype around it. Will it ever be finished ? Pricy ? Any useful ?

We´ve seen that quick, dirty and cheap solutions work well. Like the C64DTV. Not quite perfect, but cheap and available. This made it a killer piece of HW to modify. I still love mine. I also think MiniMig is great. It is available, and works great. Alot of hacks seem to surface aswell and new cores comes out now and then.

As you say, it should be possible for a A1200 "minimig". However, I wonder who will make it, and when it will be out. Price is as always in the amiga-world: way-too-much (but we like that...hehe)

Espen

[bloodline]

Palm wrote:
Has anyone a good technical answer to this:

As the MinMig works great as a A500, is it possible to do the same to the A1200 ? Or is the A1200 so much more complex than the A500, that making it in a FPGA is virtually impossible ?

Just wondering :-)


Espen

The MiniMig has a 68000, AGA needs 68020 minimum... Can you even buy 020s cheap anymore?

The minimig has 12bit video out put... AGA needs 24bit... Should be as simple as adding a few more resistors to the DACs, I think there is enough IO left on the FPGA.

AGA is poorly documented... Bug fixing would be a pain... But I expect there is probably still enough room left on the FPGA (AGA was a very limited upgrade from ECS)... I don't know how much is used right now?

[countzero]

bloodline wrote:

AGA is poorly documented... Bug fixing would be a pain... But I expect there is probably still enough room left on the FPGA (AGA was a very limited upgrade from ECS)... I don't know how much is used right now?

it really depends on the FPGA you're talking. what I know is minimig + 68k core takes about %70 of the resources of the Altera DE1 board, which is an entry level board. Higher/Newer models have an order of magnitude more space. AGA will definitely fit there. 68020, I dunno, but it should as well.

[countzero]

Palm wrote:

We´ve seen that quick, dirty and cheap solutions work well. Like the C64DTV. Not quite perfect, but cheap and available.

I don't think a quick dirty cheap solution will suffice for a AGA + 68020 machine. somebody needs to sit and think about it for a long time, it's not c64.

[mikej]

The Spartan3 400 in the Minimig is pretty close to full.
The board I have been working on has a much larger (3e1200) device and the prototypes will have a 3e1600 device on board. The video is 24 bit. There is enough IO to support an external 68020 processor, and I believe there is sufficient space in the FPGA to run a 68020 core when we have one. The jump from 16 to 32bit will expand the logic, but hopefully that will be limited to the ALU - most of the logic is taken up with instruction and address control in the softcore.

The AGA chipset is not well documented so it won't be simple to implement it accurately, there is no fundamental issue with doing so however.

I have an ST, A500 and A1200 machine with me now so I can work on the board bringup. Once I have my ST core and the original Minimig core running with my memory controller (32MByte on board) and video then I will look at expanding the Minimig hardware. I do FPGAs for a living, this board design stuff has taken far too long - once I have a nice platform I hope to get things moving quite quickly. Couple of years then


/Mike
www.fpgaarcade.com

[yaqube]

I have implemented all the AGA features into the Minimig core using MikeJ's Replay board. You can watch it running on YouTube.



As there is no 68020+ IP core available the TG68 CPU core is used. It runs at 7.09 MHz with no bus latency and according to SysInfo is 1.85 faster than a stock A1200.

The 64 MB of DDR SDRAM is configured as 2 MB Chip, 1.5 MB Slow, 8 MB Fast and 48 MB of extra memory which can be used as additional Chip memory. You can have 50 MB of Chip RAM in total.

[Hell Labs]

I like that. I like that a lot.

[desiv]

Originally Posted by yaqube

I have implemented all the AGA features into the Minimig core using MikeJ's Replay board. You can watch it running on YouTube.

WOW... Nice work....

Originally Posted by yaqube

As there is no 68020+ IP core available the TG68 CPU core is used. It runs at 7.09 MHz with no bus latency and according to SysInfo is 1.85 faster than a stock A1200.

I'm surprised that those programs and games are running on a 68000. I assumed (I know) that they would have used instructions limited to the 68020 instruction set?? Are there not that many actual differences in the two from the codes perspective?

desiv

[Cammy]

Holy crap, that's impressive! I love the way you just increased the ChipRAM so that gigantic image would load. Wow!

[NovaCoder]

Originally Posted by yaqube

I have implemented all the AGA features into the Minimig core using MikeJ's Replay board. You can watch it running on YouTube.



As there is no 68020+ IP core available the TG68 CPU core is used. It runs at 7.09 MHz with no bus latency and according to SysInfo is 1.85 faster than a stock A1200.

The 64 MB of DDR SDRAM is configured as 2 MB Chip, 1.5 MB Slow, 8 MB Fast and 48 MB of extra memory which can be used as additional Chip memory. You can have 50 MB of Chip RAM in total.

Nice, when will it be available to purchase?

[Lando]

This is a fantastic piece of work! Just wondering, how can it be accessing so much memory if it's using a 68000 core? The 68000 only has a 24 bit address bus, which would limit it to 16MB?

[koshman]

EDIT: Nevermind, a wrong thread...

[yaqube]

Originally Posted by Lando

Just wondering, how can it be accessing so much memory if it's using a 68000 core? The 68000 only has a 24 bit address bus, which would limit it to 16MB?

The TG68 IP core has full 32-bit address bus so it can access up to 4 GB of memory space.

Originally Posted by NovaCoder

Nice, when will it be available to purchase?

Mike should finish the new PCB layout in a couple of days and then should have new boards made.

Originally Posted by desiv

I'm surprised that those programs and games are running on a 68000. I assumed (I know) that they would have used instructions limited to the 68020 instruction set?? Are there not that many actual differences in the two from the codes perspective?

Those games don't use any feature specific to 020+ CPUs. I guess it was easier for developers to have the same code base for different (OCS/AGA) versions of their games.