Using C64 Core on MiniMig boards.

[mikej]

The FpgaArcade (now called Replay) board has the following :

Large Spartan3E device (1200). 3x minimig size
Expansion connector for real processor or other IO (like a real SID) / Ethernet. 68K daughter board already designed to test the 68K soft core. I can't remember the exact number, but it's got about 100 IO pins and another 30 odd input only pins plus some clocks and power on the expansion connector.

ARM micro controller for hardfile support + USB.

24 bit DVI(HDMI) output + analogue output.
Good quality Wolfson audio DAC.
32 MByte memory.

SVHS/Composite video (on tiny expansion board)

small form factor (17cm x 8cm) and fits in an ITX case.
External input connectors for wiring joysticks / buttons up in an arcade machine.

It has been a long time in development, as I keep adding bits to it. It was completely finished and ready to be manufactured before we decided to move from the AVR to the ARM controller. Should be done in another week. Price is unknown but will become clearer once I get the first batch made.

The reason I designed this board was so I can run the game cores I develop. I did the vic-20 core used on C-one and I have a cycle accurate ST chipset. I also debugged and maintain the T65 and T80 CPUs used in a lot of projects.

Any board is only as good as the software and firmware support - without this it doesn't do much. I'm an FPGA engineer, so I will continue to support the Amiga and other cores on this platform. Other people can continue to port them to other boards if they wish. Most of the emails I get are people having problems getting things to work on other boards, so having one "reference" board will from my point of view save me a lot of time.

What it will do is boot multiple environments from the OSD menu. An environment includes ROMs and the FPGA image. The ROM files are copied over to the memory at startup. You can then select a run-time image, either a floppy or later a hardfile image the FPGA can access while it is running.

My aim for platforms (initially) :
(working code exists for all of these on my other boards)

Amiga A500 - Minimig core + Mike memory controller
Atari ST - Mike + Wolfgang)
Vic20 - Mike
C64 - Peter + Mike SID
Spectrum
BBC B
Bally Astrocade
+few others

Pacman / Pengo
Frogger / Scramble
Defender
Asteroids
StarWars
Spaceinvaders


/Mike

[alexh]

Palm wrote:
Would it be possible to use the core of a C64DTV if it could be extracted somehow

It cannot be extracted. Why not? It's a modern ASIC which was synthesised from HDL and then flattened and implemented using deep submicron technology. Even if you took xray photos of the DIE you'd never work out what was going on. You can extract the information from the much older original C64 ASIC's because they were created by hand in the form of schematics using a much larger technologies making the DIE's almost human readable.

If you knew the C64DTV developers and could get a copy of the HDL source code they used then sure. (But I doubt you'd be able to get them to part with it legally)

But I feel that C64 HDL development has moved on since the C64DTV and the C64DTV was under some price constraints so they had to leave out several seldom used original C64 features.

[Palm]

I guess your´re right there Alexh. And the DTV is kinda like not really a c64. It has some extra stuff, which imo should not be there. It is too pimped up

But back to Mike´s post. I wonder if I might have bought the Minimig too early. To me, the Replay board seems to have much more coresupport than the minimig has.

However, parting with my newly obtained mini itx minimig is kinda sad too. I think that if the minimig community can get the Replay cores ported and running on minimig boards, it would be very nice.

Let us just hope that this FPGA thing does not end up in a war between the different developers :-)


Espen

[mikej]

Palm,
well, I'll say it before anybody else does - I would wait until you see pricing and the board is up and running and available for shipping.

We could hit some snag before then, but I hope not.

As the boards get more features porting the code between them does get more difficult. The integration with the micro controller is also a big deal - hence the last minute change to the ARM.

/Mike

[Palm]

If I am not mistaken, the new ARM board from Yaqube replaces the minimig PIC.

Or do I remember wrongly here ?

Espen

[mikej]

Yes. I have changed to the same controller to make sharing code easier.
/Mike

[Palm]

Ah, very nice. I like that. Good.

So when can we expect to see a demo of your board ? youtube maybe? running c64 core ? It would be very nice to see it.

Espen

[boing4000]

Could we please stay a bit on the ground?
Jakub's ARM board is not even released or finished and we are planing ahead of the not even known hardware.

Sure the Minimig board is able to run different core like FPGA64 or Atari-ST. The current PIC (or ARM board) should be able to handle different core files and the extension of disk files (i.e. .adf, .d64, .st etc.). Its also possible to rename all files in .adf as long as the sector size is still 512 byte per block. That would not require different PIC version or bit changes in its firmware, since there is no much space left.

For any new Minimig hardware releases or board revisions, the designer should be open for other core and programming ways. Right now the Minimig is an open Amiga replacement with some more options.
Don't plan ahead too much, all step by step :-)

[TheDaddy]

I agree.

Let's exhaust the Minimig first.

C64, Spectrum and Atari ST Cores, let's make sure the Minimig as it is gets fully supported and fully used.

Then, all together, we can provide an updated version which can offer more.

Just my two cents :-)

[mikej]

"C64, Spectrum and Atari ST Cores, let's make sure the Minimig as it is gets fully supported and fully used.

Then, all together, we can provide an updated version which can offer more."

I actually agree, that's why I have been using the Xilinx Spartan3e "standard" board for ages. However, I really want a board with the features I want - so I designed one. That is the one I will support from now on, it just takes too much time to do multiple ports. I feel the current minimig board is too feature limited.

To answer some other questions I have been getting, the Replay board will only be available fully assembled and tested - it's not easy to build by hand even with professional tools.

/Mike

[alexh]

Quick n dirty ports are very easy. You can usually have something on the screen in 20 minutes. For Spectrum you can create the port very quickly because it was written very well. Add the MiniMig I/O wrapper for CLOCKS, RAM/ROM, VGA, Joystick and keyboard and combine the ROM and an SNA file to replace KICK.ROM. A few pokes and an RUSR and you're playing the game. Not particularly user friendly as it is only one game per SDCARD ;-)

To get it to work better you need a replacement OS or HDL to replicated either the Disciple or +3 interfaces.

Like most things it's no fun once you've got it working a little bit. It becomes "work" to get it that next bit further, at least to me.

[alexh]

boing4000 wrote:
The current PIC (or ARM board) should be able to handle different core files and the extension of disk files (i.e. .adf, .d64, .st etc.). Its also possible to rename all files in .adf as long as the sector size is still 512 byte per block. That would not require different PIC version or bit changes in its firmware, since there is no much space left.

But that's just it, AFAIK they are not the same (although I've never tried)

AMSTRAD / Spectrum +3 DSK format for example has different possible sector sizes and non are the same as Amiga ADF.

However I'm not sure for MiniMig how much of the disk image file access is inside the PIC and how much is inside the FPGA. If all the track/sector handling is inside the FPGA and it just requests data from the PIC as an offset within the file then it should be possible to use the existing PIC (at least for reads).

[Palm]

Taken into consideration that the minimig is quite a nice board, we should be able to get alot of cores running on it before switching to a new mobo probably. If the Replay and the MiniMig users keep fairly good sharing between the mobos and if cores can be shared for these two boards without too much hazzle, it would be nice with another mobo on the market. Nice to have a choice. But my biggest fear is that the boards (and future fpga board) develop in different direction so that neither boards can share cores easily. That is kind of like a lose-lose situation for all of us. Maybe a common roadmap for the developers of the boards would be a good idea.

I am sticking to my minimig hoping for a c64 core soon. That makes my world a perfect one One CD card labeled "Amiga" and the othe "C64". Could I ask for more ? :-)
(oh, I could...but I wont hehe)


Regs
Espen

[TheDaddy]

>>Taken into consideration that the minimig is quite a nice board, we should be able to get alot of cores running on it before switching to a new mobo probably.

Totally agree. I want to use it to its fullest and make sure it becomes a mature product, like a classic Amiga and keep it.

Also I make and produce the cases for this little beauty :-)

>>But my biggest fear is that the boards (and future fpga board) develop in different direction so that neither boards can share cores easily.

This will eventually kill one of the two boards and that is a shame.

>>I am sticking to my minimig hoping for a c64 core soon. That makes my world a perfect one One CD card labeled "Amiga" and the othe "C64". Could I ask for more ?

Totally with you there :-) It makes sense to exploit the Minimig to the full, hoping for a C64 core and more cores later on.

[Palm]

Yes. Fingers crossed. Regarding casing, I have the ITX version so I have the possibility to choose standars ITX ones, but they are expensive as hell :-( So I am gonna make a simple homemade PLEXI box for it instead. Will cost me a fraction of a commercial mini itx casing.

Did you make that white nice box in plastic ? If so, great work. Looks very nice.

Even though minimig dies in the end because other boards are for sale which has more power and more capacity, that doesn´t matter too much because every board has its lifespan, and the minimig is not that new anymore. But it was "the" board which probably kickstarted all this amiga-in-a-chip in the beginning. I am very thankful for both the minimig board and Dennis´ work here. But as time goes by, more people will follow in his footsteps and make better boards. And this is just normal i guess. It benefits everyone. It is just a shame that the market for these boards are limited to the retro-people. So not much money to earn here. Although, they do earn quite some respect in the community, and this is priceless, right ? ;-)))


Regs
Espen

[TheDaddy]

>>standars ITX ones, but they are expensive as hell  

I know, I have built a few pcs using those cases.

>>Did you make that white nice box in plastic ? If so, great work. Looks very nice.

Thank you. The second batch arrives tomorrow. 50 cases, 30 have already been booked and paid for. So if anyone needs one let me know.

>>It is just a shame that the market for these boards are limited to the retro-people. So not much money to earn here. Although, they do earn quite some respect in the community, and this is priceless, right ? ))

Well, as the designer of the Minimig case I can tell you that you are absolutely right. :-)