Welcome, Guest. Please login or register.

Author Topic: FPGAARCADE minimig compatible board, comments?  (Read 32997 times)

Description:

0 Members and 1 Guest are viewing this topic.

Offline mikejTopic starter

  • Hero Member
  • *****
  • Join Date: Dec 2005
  • Posts: 822
    • Show only replies by mikej
    • http://www.fpgaarcade.com
FPGAARCADE minimig compatible board, comments?
« on: March 17, 2008, 10:52:42 PM »
Hello all.

I have been developing a board for a while to run the games developed at www.fpgaarcade.com. I have also been working towards a gate-level perfect AtariST clone (ok, wrong forum :) ). Having talked to Dennis I decided to include a similar bootloader to Minimig so it can also run the Amiga hardware.

This is how it stands at the moment (its about 90% placed, some components are missing).


The board size is ECX but it has got slightly bigger today and is now "EPIC/ narrow mini-ITX" 17 cm wide by 12 high. It will fit in an ITX case and the two front screws are correct. It is a slightly ~6mm oversize EPIC format.

I wanted to keep the base board as simple as possible, everything platform specific would go on a daughter card. This increases the cost though, so I added some connectors at the top but these would not be fitted. The daughter board can be stuffed with whatever connectors you wish. Two daughter boards are being designed, one has the joystick ports over the bottom connectors and TV out, and the other has a JAMMA edge connector for arcade game cabs.

It has DVI out as well as 30bit analogue RGB on the DVI connector. You can plug in a 15 pin VGA adapter or a cable to your SCART TV. It has a high quality audio output as well.

The PIC has a bootloader so it can be updated by the serial port (if it works!)

The FPGA is quite a bit bigger than the one on Dennis' board (Spartan3E ~ 1.2 M gates), so I am hoping the 68K processor would not need to be fitted and we would use TobiFlex's core. (Hello again!)

The RAM is DDR DRAM and there is 64MB of it, maybe more. I will come up with wrappers for the Minimig code so it runs on this board. What I want to get to is the bootloader loads a default FPGA image at startup which drives the on screen menu. You then choose the platform (Amiga/Atari/Pacman/HD Asteroids etc) and the disk images / roms.

I will do a small production run when it all works as it is tricky to solder BGAs at home :(

Any comments? There is still time to tweak it....
Should the base card have composite / SVHS TV out, or is the DVI into a HDMI tv good enough? Do modern TVs work at 50Hz with HDMI actually, I don't have one???

Thanks,
Mike.
www.fpgaarcade.com

 

Offline AJCopland

Re: FPGAARCADE minimig compatible board, comments?
« Reply #1 on: March 17, 2008, 11:26:39 PM »
I'm justing crashing out now so quick reply!

Great to see you getting this board done, I've been following your FPGAArcade site for a while and hoping you'd get this done (and the jaguar 2 FPGAs *ahem*:-D).

Could a 68k series CPU be put on a daughter card slot that you're currently planning to use for JAMMA boards or would there not be enough IO? I'm just thinking that TobiFlexs 68k is great but it'd be nice to have a hardware option or to allow for other 680x0 series cpus to be swapped in.

If it could have composite/SVHS as well that'd be good so that people could connect it to their regular TVs. What connector was used for the older hi-res arcade screens?

Andy
Be Positive towards the Amiga community!
 

Offline mikejTopic starter

  • Hero Member
  • *****
  • Join Date: Dec 2005
  • Posts: 822
    • Show only replies by mikej
    • http://www.fpgaarcade.com
Re: FPGAARCADE minimig compatible board, comments?
« Reply #2 on: March 17, 2008, 11:37:13 PM »
Thanks!

All the 68K pins also go to the connector as I expect the CPU wont be fitted. There is a lot of IO there so anything is possible, faster CPU no problem. I don't see any reason why we can't get the soft68K upto silly speeds actually, the DRAM controller should keep up.

All reasonably modern arcade machines use the JAMMA connector, older ones had custom ones. I also want to do a daughter card to drive vector monitors for StarWars :)

You can wire to the regular telly using a vga to scart cable, the chip will output PAL/NTSC and composite sync on the H sync pin (look at my vic20 page). Question is, to keep the base board cost down can the composite video out go on the optional daughter board???

Actually I have been making some good progress with the JAG2 stuff, I have a working cell simulation library that is nearly consistent. Most of the work recently has been finishing off the Atari customs, but that is mostly done. Full focus on getting this board done now, my deadline was Easter....
/Mike
 

Offline freqmax

  • Hero Member
  • *****
  • Join Date: Mar 2006
  • Posts: 2179
    • Show only replies by freqmax
Re: FPGAARCADE minimig compatible board, comments?
« Reply #3 on: March 18, 2008, 10:31:00 AM »
Why 2x PS2 ports on opposite sides ..?
SMPS or Linear (hot-hot) regulators ..?
Configuration jumpers for video signal ..?
 

Offline TheDaddy

  • Hero Member
  • *****
  • Join Date: Feb 2005
  • Posts: 1154
    • Show only replies by TheDaddy
    • http://www.loriano.pwp.blueyonder.co.uk
Re: FPGAARCADE minimig compatible board, comments?
« Reply #4 on: March 18, 2008, 10:57:48 AM »
Hi,

I have been following your fpga site for about a couple of years and I always wondered when you were going to come out with a FPGA Amiga.

Will this board be like an A1200? Or a generic board which allows you to run anything from Atari to Amiga?

Thanks :-)
 

Offline alexh

  • Hero Member
  • *****
  • Join Date: Apr 2005
  • Posts: 3644
    • Show only replies by alexh
    • http://thalion.atari.org
Re: FPGAARCADE minimig compatible board, comments?
« Reply #5 on: March 18, 2008, 11:29:17 AM »
Quote

TheDaddy wrote:
Will this board be like an A1200 with AGA implementation?

What has the board to do with implementations?
 

Offline TheDaddy

  • Hero Member
  • *****
  • Join Date: Feb 2005
  • Posts: 1154
    • Show only replies by TheDaddy
    • http://www.loriano.pwp.blueyonder.co.uk
Re: FPGAARCADE minimig compatible board, comments?
« Reply #6 on: March 18, 2008, 11:44:19 AM »
What I meant was:

Is this board going to be able to run AGA programs?
 

Offline Krusher

  • Sr. Member
  • ****
  • Join Date: May 2003
  • Posts: 450
    • Show only replies by Krusher
Re: FPGAARCADE minimig compatible board, comments?
« Reply #7 on: March 18, 2008, 11:49:52 AM »
Quote

TheDaddy wrote:
What I meant was:

Is this board going to be able to run AGA programs?


If someone is capable and willing to port the minimig source and implement AGA support, yes. The used FPGA has enough gates anyway.
 

Offline AJCopland

Re: FPGAARCADE minimig compatible board, comments?
« Reply #8 on: March 18, 2008, 11:49:58 AM »
I believe, from his comments, that MikeJs board design is made to be able to emulate multiple platforms, either by using other cpus on daughter boards or everything in the onboard FPGA.

This means that, to answer your example: You could put a 68020 on a daughter board AND if you had an FPGA implementation of the AGA chipset that you could put into the onboard FPGA, then yes you could use it to emulate an A1200.

MikeJs earlier post was saying that because the FPGA he has used is much larger than the one in the MiniMig (3x larger!) it should be able to fit both the MiniMig OCS chipset and TobiFlexs tg68k into the FPGA together so this could become a good board for MiniMig projects.

However he's designed it so that it could be used for the implementation and emulation of many other systems.

That clarify?

Andy
Be Positive towards the Amiga community!
 

Offline bloodline

  • Master Sock Abuser
  • Hero Member
  • *****
  • Join Date: Mar 2002
  • Posts: 12113
    • Show only replies by bloodline
    • http://www.troubled-mind.com
Re: FPGAARCADE minimig compatible board, comments?
« Reply #9 on: March 18, 2008, 11:58:08 AM »
Quote

AJCopland wrote:

However he's designed it so that it could be used for the implementation and emulation of many other systems.



I would also note that this board supports 24bit output, which is needed for AGA support... this, I believe is the largest impediment for the AGA support on the MiniMig (with its 12bit gfx)...

Offline AJCopland

Re: FPGAARCADE minimig compatible board, comments?
« Reply #10 on: March 18, 2008, 12:04:50 PM »
I'd counter that the largest impediment to A1200 emulation on the current MiniMig v1.1 is the use of the 68000 rather than a 68020 or better :-D

The bit depth would only affect colour output rather than logical implementation whereas attempting to persuade programs made for a 68020 to run on a lower clocked 16bit data/address wide cpu would probably be an unsurmountable hurdle :lol:

Andy
Be Positive towards the Amiga community!
 

Offline jkonstan

  • Full Member
  • ***
  • Join Date: Dec 2005
  • Posts: 243
    • Show only replies by jkonstan
Re: FPGAARCADE minimig compatible board, comments?
« Reply #11 on: March 18, 2008, 12:28:50 PM »
Mike,

Please post a pdf of the schematics so that we can give some better "design review" like feedback. Also, add an IDE connector via Spartan3e/level shifters (CBT16245).

 :-)
 

Offline Dennis

  • Full Member
  • ***
  • Join Date: Dec 2005
  • Posts: 128
    • Show only replies by Dennis
Re: FPGAARCADE minimig compatible board, comments?
« Reply #12 on: March 18, 2008, 12:48:22 PM »
What PIC are you using?
Could you use one of those newer PIC18F..J types?
These run faster and at 3.3V, have more RAM and ROM and are easily programmable using a PICKIT2 header.
I don't know about tiny bootloader though, that may have to be ported but that should be easy.

Dennis
 

Offline bloodline

  • Master Sock Abuser
  • Hero Member
  • *****
  • Join Date: Mar 2002
  • Posts: 12113
    • Show only replies by bloodline
    • http://www.troubled-mind.com
Re: FPGAARCADE minimig compatible board, comments?
« Reply #13 on: March 18, 2008, 12:49:45 PM »
Quote

AJCopland wrote:
I'd counter that the largest impediment to A1200 emulation on the current MiniMig v1.1 is the use of the 68000 rather than a 68020 or better :-D


Which is why I said AGA and not A1200 :-)

Quote

The bit depth would only affect colour output rather than logical implementation whereas attempting to persuade programs made for a 68020 to run on a lower clocked 16bit data/address wide cpu would probably be an unsurmountable hurdle :lol:


Hmmm... maybe...

Offline TheDaddy

  • Hero Member
  • *****
  • Join Date: Feb 2005
  • Posts: 1154
    • Show only replies by TheDaddy
    • http://www.loriano.pwp.blueyonder.co.uk
Re: FPGAARCADE minimig compatible board, comments?
« Reply #14 on: March 18, 2008, 12:50:23 PM »
@all

Thanks for the explanation. :-D