FPGA Replay Board

[wizard66]

Sweet all golden oldies from the 80"s
Nice to have a c64 and a speccy at some point..
Let the games begin ... ;-)

[psxphill]

...yet... but the expansion slot is fully capable of all of these things. SCSI is of particular importance to me.

I'd rather see SATA than SCSI support, at least you can still buy the hardware for a reasonable price. The command sets have become mostly common now to the point where Windows often refers to SATA devices as SCSI. The speed would truly be remarkable.
 
Adding SCSI-I is probably cheaper though, you could do a SCSI controller in the FPGA and run out some I/O to a connector on the board. You could do the same for a cheap ass IDE implementation as well (like commodore did).
 
The problem of course is going to be coming up with a one size fits all board. Realistically it's unlikely there will be more than one expansion board designed and manufactured & my guess is you're going to want mike's board with the full 68060 and extra ram and ethernet.
 
Adding an CD/DVD drive could probably be done using USB, but that is probably harder than adding SATA. I'm especially thinking about games consoles where you won't have a USB stack and the extra latency of emulating direct access would probably kill it (i.e. you're reintroducing the same problems that Windows has).

[Everblue]

Btw how is the c64 core coming up?

[JimDrew]

You could do a SCSI-II controller in the FPGA (plenty of gates left), but I happen to have about 2000 53C80 chips sitting here to give me SCSI.  SCSI is exclusively used by the Mac, and for the Mac emulation I will need SCSI support to access things like Syquest drives, CD-ROM drives, tape drives, etc.. all of the same stuff that is plugged into my A3000.

The way Mike setup the menu system and such is really nice.  It makes it easy to just load a new core on the SD card, update a .ini file and presto, new game or emulation is available.  This is the way it should be done!

[freqmax]

Wolfgang has some pictures of Phoenix here ...
http://pin4.at/pro_arcade_phoenix.php

How come his 8085 design uses so much FPGA resources?

[JimDrew]

This is from his website:

Due to the implementation of the "analogue" sound section, it barely fits to small 500E boards (100% utilization) and I don't have the external flash feature implemented yet.
It has some possibility for a "low HW cost" sound implementation - but you do not really want that, do you...?

[freqmax]

Gah.. missed that. Seems mystery is solved.

The Amiga in FPGA poses a somewhat similar problem when used with S/P-DIF or HDMI-audio (digital sound). As the Amiga sampling frequency may vary significantly but the output will not. A constant difference in frequency of course add another frequency, then there's aliasing etc.

[psxphill]

As the Amiga sampling frequency may vary significantly but the output will not. A constant difference in frequency of course add another frequency, then there's aliasing etc.

I don't believe the Amiga sample rate does vary, all samples appear to be output relative to the colour clock.
 
http://blog.kebby.org/?p=11
 
http://eab.abime.net/coders-general/63227-low-level-workings-paula.html
 
3.58mhz is a little high to be outputting though. The Amiga will put that through some form of filter, even when the low pass filter is off.
 
From what I can tell the 2 bytes in the AUDxDAT register get output alternatively for 64 clocks, the audio changes when another 2 samples are loaded (either via dma or cpu). Which kinda sounds like it would cause a lot of noise artifacting, but apparently not (although paula does sound a bit crunchy at times).
 

You could do a SCSI-II controller in the FPGA (plenty of gates left), but I happen to have about 2000 53C80 chips sitting here to give me SCSI. SCSI is exclusively used by the Mac, and for the Mac emulation I will need SCSI support to access things like Syquest drives, CD-ROM drives, tape drives, etc.. all of the same stuff that is plugged into my A3000.

I would hope the Mac emulation will work without any real SCSI peripherals though, at that point you probably don't want to use a real 53C80 as you'd be limited to only having real peripherals or only having emulated ones. If you emulate the 53C80 then you can have a mixture of real and virtual peripherals, plus it would be nice if you could use the same interface for emulating any machine with SCSI whatever controller chip it uses.
 
Of course you can go ahead and make your own expansion board with a 53C80 if you like, but it is likely it will have a very small audience as everyone is likely to want the board with the real 68060 and the people who need an emulated SCSI controller chip will have to effectively redo the same work. While if we could persuade mike to just throw on some SCSI/IDE connectors (or even space for them) then it would meet everyone's needs (except your manufactured need of finding somewhere to put these 53C80 chips).

[Everblue]

I've been looking at the game Minimig compatibility list here:

http://www.opencircuits.com/Minimig_Software_compatibility

Would this be valid for Arcade FPGA or by now the core would have been fixed to make more games work?

[gaula92]

@EverBlue: that list is terribly outdated!
On the Minimig V1.1 board, it's very VERY hard to find a single game that doesn't work these days. Boing4000, Mmrobinsonb5, Chaos... these guys at the minimig.net forum have fixed most incompatibilities by now. I think the only game that doesn't behave as intended is some obscure Asterix game because it uses the mouse in a strange way.
I have hundreds of Amiga games on the Minimig V1.1 board (Whdload versions, who cares about slow ADFs anymore??) and they all work.

I'd say compatibility is more or less the same on the DE1 board (TG68 68000 softcore) if you use Chaos's latest testing core, but  I haven't tested it so hard as the Minimig V1.1, wich is my main Amiga these days.

I believe MikeJ incorporates every Chaos's CPU fix to the unreleased new core, so we can expect a similar compatibility. Correct me if I'm wrong, Mike.

[Everblue]

I assume arcade fpga = DE 1?

The arcade fpga is the reason I haven't bought a minimig with an arm controller, due to AGA compatibility and DVI (if it had HDMI would have been perfect). Hoping they are shipped out soon.

Just curious is there a working c64 core for the Minimig?

[psxphill]

(if it had HDMI would have been perfect).

Unfortunately HDMI is expensive to add. The video is easy to convert from DVI-D to HDMI as it's just the connector, but getting the audio in the correct format is not as simple. However a lot of DVI connectors on PC graphics cards include HDMI compatible audio as well, ATI seem to just put the interleaved video and audioover DVI-D.
 
http://www.mcscom.co.uk/live/index.php?route=product/product&product_id=22510
 
"With the correct hardware this adapter allows you to transmit high-definition digital audio from your PC using a single HDMI cable. Generic DVI-HDMI adapters do not support this function and only transmit the video signal."
 
What I don't know is what stops the standard cable from working, whether it's just a case of the graphics card detecting the special ATI dongle.
 
I believe NVidia also have an adapter, but they use a different method that involves SPDIF and are supposedly less compatible. I can't find a technical description of how that works either.
 
People selling adapters don't help http://www.ebay.co.uk/itm/Replacement-DVI-Male-to-HDMI-Female-Audio-Plug-Adapter-/390611645116?pt=UK_Sound_Vision_Other&hash=item5af244b2bc

[Darrin]

I've been looking at the game Minimig compatibility list here:

http://www.opencircuits.com/Minimig_Software_compatibility

Would this be valid for Arcade FPGA or by now the core would have been fixed to make more games work?

If you look at the core used for most of the testing (080408) you can see that the list was done back in August 2008.  There have been a lot of updates since then.

I started to make a new list using the Minimig, Chameleon and FPGA Arcade, but I stopped because I was waiting for the new FPGA Arcade core.  Once I have it (and some spare time) I'll start again.

[Everblue]

What about one of these (expensive) adapters?

http://www.ebay.co.uk/itm/StarTech-com-DVI-to-HDMI-Video-Converter-with-Audio-Video-converter-black-/380549230284?pt=UK_Computing_Other_Computing_Networking&hash=item589a806ecc

Unfortunately HDMI is expensive to add. The video is easy to convert from DVI-D to HDMI as it's just the connector, but getting the audio in the correct format is not as simple. However a lot of DVI connectors on PC graphics cards include HDMI compatible audio as well, ATI seem to just put the interleaved video and audioover DVI-D.
 
http://www.mcscom.co.uk/live/index.php?route=product/product&product_id=22510
 
"With the correct hardware this adapter allows you to transmit high-definition digital audio from your PC using a single HDMI cable. Generic DVI-HDMI adapters do not support this function and only transmit the video signal."
 
What I don't know is what stops the standard cable from working, whether it's just a case of the graphics card detecting the special ATI dongle.
 
I believe NVidia also have an adapter, but they use a different method that involves SPDIF and are supposedly less compatible. I can't find a technical description of how that works either.
 
People selling adapters don't help http://www.ebay.co.uk/itm/Replacement-DVI-Male-to-HDMI-Female-Audio-Plug-Adapter-/390611645116?pt=UK_Sound_Vision_Other&hash=item5af244b2bc

[Everblue]

If you look at the core used for most of the testing (080408) you can see that the list was done back in August 2008.  There have been a lot of updates since then.

I started to make a new list using the Minimig, Chameleon and FPGA Arcade, but I stopped because I was waiting for the new FPGA Arcade core.  Once I have it (and some spare time) I'll start again.

Thanks!

I wasn't aware the list is so out of date. Great so see most if not all games work. Can someone lend me a minimig until I receive my Arcade FPGA

[SamuraiCrow]

Re:HDMI vs. DVI

Full HDMI have more than just audio added into the standard.  DVI is unencrypted video while full HDMI is encrypted to disallow people from just recording lossless video onto a BluRay burner.  The licensing and associated circuitry for HDMI make it undesirable for hobby projects since they would never be able to successfully defray the costs of adding the encryption circuits as opposed to high-volume retailers which are more worried about the outputs being used to pirate video outputs.