FPGA solution for special chips on SNES?

Im about to order the everdrive MD, since it has nearly perfect compatibility with MD games. Virtua racing ill play the superior 32x version

Now i read a couple of discussions about the everdrive and other romcards about the lacking special chips, some suggested having a socket to solder a real chip into, which wouldnt be so bad idea if it was only one special chip, but there are nearly a dozen for the SNES, and sadly for me personally some of the best games like super mario world 2 depend on those special chips.

Recently i played around with the DSTWO flashcard for the NDS. IT uses a FPGA to emulate all of the SNES instead of the internal CPU, and does it quite smoothly.

So my suggestion would be, why not try to implement an FPGA onto the PCB?

The DSTWO uses a Actel ProAsic3, a very small/cheap and lowpower FPGA chip pictured in the link below
http://gbatemp.net/news/09_supercardds2_review_pcb_front.jpg

Specificly it uses the A3P125 version, found in the datasheet of Actel below
http://www.actel.com/products/pa3/

They name the unitprice as low as $0.99, assume that the one needed to emulate everything perfectly is $2 or $2.5 worst case scenario.

The sourcecode for all the special chips is available at (im sure a deal can be made with the developer )
http://www.zsnes.com/index.php?page=files

Of course this would still involve quite some work to get it running perfectly, but while i find $80 not quite justified for the limited compatibility, if you made this card with the FPGA with near 100% emulation i would put down $120 for it in a heartbeat. Also any other romcard manufacturer would be put out of business since it would not have any competition, again more profit!

I hope the idea is consider

 

1) why you thinking that A3P125 do snes emulation? 1024 macro cells it is too small for snes implementation, or even for spec chips only implementation. here need some like altera cyclon or eq and such class of chips price much more 2.5usd, 40usd min i gues .

2) C sources totally unusable for FPGA implementation, even as sample

3) i dont want to spend 400-500% more time for make just little more popular device, or even it will be not so popular device as current, because all want chips compatibility, but nobody want pay 2x or 3x price. who need costly device just for few good games? you easy can buy original games for few $ on ebay. so i think that spec chips implementation is irrational step

 

FPGAs are not magic. Cloning the special chips would take a significant investment of time. Some chips are used in a good bunch of games while others are used in 1 or 2 games. Not at all worth the effort in cloning them on a FPGA.

As KRIKzz said, the original cartridges are not that expensive if you want to play those games. But the cost to add support for those games to EverDrive would probably equal or maybe surpass the cost of buying all the games you would want to play.

It would be awesome if you could play absolutely 100% of the SNES library on one flash cartridge or copier but that's very unlikely to happen and if it ever does it will cost probably much more than you are willing to pay.

 

To add to this, the FPGA used in DS adapters are not used for their FPGA abilities, they are used as quick-time-to-market ASIC. In order for a single FPGA to be reused across multiple special chips and core logic it would need even more external logic to bootsrap and reprogram the FPGA or the FPGA would have to be self-reconfiguring which is a very tricky process that few people in the entire industry dare to attempt (and I think there is often a $2K+ license for this feature on development environments). You, sir, are misguided about the technology (clearly there are more real life limitations on things than you realize), and are cheap

Why is it that everyone thinks this stuff is easy to pull off???

 

Like Igor said in the end this comes down to money. I am sure if he could sell 100,000 of these next year if it supported these chips it may be worth the investment to figure out a solution.

However, we are talking about a niche market of an already niche market item that has heavy competition from emulators and next gen virtual consoles. If doing this was easy RetroUSB, TotoTek, or Igor would have done it by now.

 

With the decapping of the dsp-1 (and the dump of the rom), can it be adapted to a pic ? Either by using the uPD77C25 emulator inside bsnes, or by reversing the rom using Overload's disassembler.

 

uPD77C25 capability unknown for me, but i think uPD77C25 can be replaced by some modern MCU

 

I didnt know the DSP-1B had been decapped and the ROM dumped :-0

I think DSP-1B support using an MCU would be fantastic, expecially since it is the most commonly used SNES special chip. Is this something you are already working on KRIKzz?

 

no, i not worked over it, to many time need. much more easy to use dsp from donnor cart. i not hacker and in revece engineering i also not a master. i can create some hardware only if i have specification. code repair from binary or some similar things is not for me.

 

it seems to be very recent news. see this interesting article of the well know byuu. http://byuu.org/articles/decap

don't forget the link to the Dr decapitator's page http://decap.mameworld.info/

 

RetroUSB actually has implemented DSP1 but it is not possible to do more than one special chip on one cart. There is a total of 28 games I believe that use the other chips and out of that 28 there are like 3 good ones. So I chose to buy the Powerpak and the 3 good SuperFX games. This was before Krikzz made his SNES cart or I may have considered his just because of price. $135 is not a casual spend, but I personally feel it was worth it.

 

he not implement dsp on some custom hardware, he just used original chips from donnor carts. look here

 

Yes it was originally like $11 US to get the donor chip installed. Now it's included. RetroUSB's SNES cart has suffered a lot of problems with the CF Card scheme as well. I think he only recently fixed all of it, but it required sending it back to him for updates.

 

Greg2600: What problems are you referring to? I have had my SNES Powerpak since the first week he offered it and never had any issues with anything.

Kirkzz: Ahh I was not aware that they were donors. Either way though it works quite well.

 

Most people seem to be fine but there's also a lot of people who've had serious issues. Myself included - I've tried my PowerPak on three different Superfamicoms and it hasn't worked right on any of them. If I remember right, two give errors right at the start and won't load games, the other loads games but hangs almost immediately (at the developer logo or menu). If he's released new fixes I should probably check it out, but I've just about given up on the fucking thing, to be honest.

 

Ahhh...I use a US SNES..maybe that's the difference. Who know. I was not aware of any issues since mine has always been well worth the $135. But I can see how issues could occur on different hardware types. I wish you good luck on it Alchy.

 

the solution is easy, use a T-connector like Tototek, you pop in a cart with the chip you need, the flash cart checks the cart on the t-connector and launches the game.

maybe the tototek t-connector will work already?

 

I believe someone has stated it already does. Keep in mind though, the T-connector will only help with DSP1 games.. not c4 or superfx or any of the other chips.

 

hmm, I thought the tototek t-connector worked with any chip as long as you had game with the right chip inserted. here is the link:

http://www.tototek.com/store/index.php?main_page=product_info&cPath=1_8_11&products_id=40

but honestly I can not make it out form the engrish description of it so you're probably right if it has already been discussed.



the retrousb snes cart already has dsp1 game support built in so it would seem THAT cart has a one-up on the krikzz snes cart.

 

The english description only mentions super mario kart (DSP1 game) and no others....

Also, i believe KRIKzz is putting out a revision of the SuperEverDrive at some point with an area to solder in a DSP1 chip... which is what the SNES PowerPak does.