Flash cart development

Started by arfink, August 10, 2010, 01:39:11 pm

Previous topic - Next topic

arfink

I am new to this forum, so be sure and tell me if I'm doing something naughty by posting this. I read the rules and it looks like probably not, but just in case. ;)

I and a friend are developing a reprogrammable USB-enabled flash cartridge for the NES, and our design would work on the Famicom as well. The only problem is, we have no idea if there would be significant interest in a Famicom version of our design.

The cartridge, currently known as the Munchausen Cart, is an MMC1 flash cartridge which can support up to 6 NROM games with a selection menu or 1 MMC1 game that uses 8kb CHR RAM, up to 256kb PRG, and it also provide 8kb of battery backed SRAM if the game needs it. The design is fairly simple. The cart contains bootstrap code which can detect the presence of a pre-loaded game and run it, or can load a new game to the cartridge via the 2nd player controller port, which connects to USB with a special cable. On the Famicom this cable would attach to the expansion port.

The intended cost for this cartridge and cable together is currently around $40 to $50. Right now we are building prototypes and honing the code, and I hope to have some production or at least pre-production units made up by the end of August. Does this kind of thing sound interesting to any of you? If not pre-made cartridges, would a DIY tutorial or kits be of interest?

Also, if you want a boatload of tech details etc, you can look at this thread here:
http://chipmusic.org/forums/topic/2004/blargg-bootstrap-usb-cartridge-coming-soon/

i heart yuna

I don't know about anyone else,but I think a Famicom flash cart would be amazing.
Famicom Club! http://www.famicom.ca

nintendodork

Yeah.  I figured RetroUSB would've already taken care of that but I guess not.
I like to glitch old VHS tapes and turn them into visuals for live music events. Check out what I'm working on - www.instagram.com/tylerisneat

arfink

Quote from: i heart yuna on August 11, 2010, 03:19:52 pm
I don't know about anyone else,but I think a Famicom flash cart would be amazing.

Thanks for the feedback.

Quote from: nintendodork on August 11, 2010, 03:33:41 pm
Yeah.  I figured RetroUSB would've already taken care of that but I guess not.

Well, if the PowerPak was adapted to Famicom it would be a gigantic cart, which is why I think they didn't do a Famicom version. My design will be smaller primarily because it can't do eveything the PowerPak can do.

satoshi_matrix

I don't mean to discourage you, but with the Powerpak on the market already, I don't see how an MMC1 only flashcart could even hope to be competitive.

Even if you were to sell the Flashcart at half the price of the PowerPak (that would be around $68) the cost of manufacturing would likely make your even price somewhere around there if not higher.

That said, what I would be interested in in something that does everything the Powerpak does but be 60 pin for the Famicom. As you expressed, the interest in this kind of device is very limited and you'd likely not be able to do it.

Bummer man.

arfink

August 12, 2010, 09:52:35 am #5 Last Edit: August 12, 2010, 09:57:55 am by arfink
Quote from: satoshi_matrix on August 11, 2010, 08:15:46 pm
I don't mean to discourage you, but with the Powerpak on the market already, I don't see how an MMC1 only flashcart could even hope to be competitive.

Even if you were to sell the Flashcart at half the price of the PowerPak (that would be around $68) the cost of manufacturing would likely make your even price somewhere around there if not higher.

That said, what I would be interested in in something that does everything the Powerpak does but be 60 pin for the Famicom. As you expressed, the interest in this kind of device is very limited and you'd likely not be able to do it.

Bummer man.


Interestingly enough, I had thought that myself. However, I am finding there is a very high amount of interest for this device in the homebrew community and chiptune community. My device should support two very popular trackers for the NES as well as running NSF files, and there is an abundance of VJ-oriented software that will run on my cartridge as well. A number of developers are actually designing their programs to be able to run on this. Now, for the average gamer who just wants to pop his whole Famicom ROM collection onto one device this won't be very useful for that, but as a very cheap development cartridge I think the design will be successful. Competing with the PowerPak was never something I was prepared to do with this, but simply to provide something that the code makers, tinkerers, and their users can make use of.

Also, one other thing that the developers like about my design is that since the NES is essentially made into a configurable UART with the cartridge and USB cable hooked up it is possible to quickly change code without removing the cart or even powering the system down. In fact, changing code located in RAM is possible even while the NES is executing code. While this could conceivably be done on the PowerPak, it's not really designed with that in mind.

In order to keep costs down I am planning to be making these myself. They will not need to be professionally manufactured because the design is quite strikingly simple. I find that a $40 price tag will probably be pretty accurate when all is said and done. So, since I'm making them myself and to order I don't have to really worry about competing with the PowerPak at all.

satoshi_matrix

I see. Again I wish you luck.

michaelthegreat

Sounds cool, but I don't think you'll get tons of famicom interest. Most famicom collectors have lots of multicarts with tons of nrom games already... And for those who own famicoms, definately having the carts is part of the experieince. Not many of the must-have games will play off your cart either. So I hope it works well for the nes community, but I'm not sure if the famicom community will get you  many sales.

arfink

Eh well, not a huge deal then. I haven't exactly tooled up for Famicom, since I'm doing these on a per-order basis and the procedure is essentially identical for NES and Famicom. I'll probably make one for myself and call it a day, unless somebody else suddenly becomes interested.

satoshi_matrix

Despite all that I've said, I may perhaps be interested. Will this cart only play MMC1 games? No UNROM or similar?

UglyJoe

Can you explain its ability to modify RAM in a bit more detail?  Sounds like it'd be a lot more useful as a development tool than the PowerPak is.

arfink

Sorry to take so long to reply.

First to Satoishi, the cart will support MMC1 with CHR RAM and also NROM. UNROM, CNROM, AOROM, etc. might be a future possibility, but I am not really sure if I can make them work with the current design. At the moment the cart also supports multiple ROMs, so you can have 1 MMC1 game and 2 NROM games, or 6 NROM games, menu selectable.

As for RAM modification and such, it's really entirely up to the creativity of the coder. The bootloader is capable of putting the data you send into the Flash and from there into any RAM bank. The serial cable could also be utilized by your custom software for other purposes as well. Some developers have been interested in my design for things like live NSF playback, for example.

If you want to get more information and more technical details than you probably need, please check this thread (it's on another forum, I know) http://chipmusic.org/forums/topic/2004/blargg-bootstrap-usb-cartridge-ntrq-and-lightwall-demos/

On page 7 you'll find some of the latest info. I'll hopefully post more here soon when I have the time, but that forum is the place that gets the most updates the most frequently.

Just ask if you have more questions!

UglyJoe

Quote from: arfink on August 19, 2010, 10:35:21 am
As for RAM modification and such, it's really entirely up to the creativity of the coder. The bootloader is capable of putting the data you send into the Flash and from there into any RAM bank. The serial cable could also be utilized by your custom software for other purposes as well. Some developers have been interested in my design for things like live NSF playback, for example.


Sounds good.  Definitely interested in getting one once they're ready.

arfink

If you'd like to see the current state of the prototype stage, please view this little video I made:

http://www.youtube.com/watch?v=nM-ayjjLYdA

arfink

OK, it's about time I put some good info down for people, and lots of pics:

NES label design by Pixls


Famicom label design by Pixls


Current state of prototype PCB (back)


Current state of prototype PCB (front)


Beta software game select menu


Beta software recovery mode


The cartridges will retail for $50. The probable release time for the beta hardware is estimated at 2-3 weeks. Public orders will be accepted for an official production run approx 1 to 2 weeks after the beta testing period.

Current specs on the cartridges:

-NES and Famicom carts will be available
-512kb Flash chip
-USB programmable
-PC side software available for Windows, Linux, and Mac OSX
-Supports MMC1 with CHR RAM and battery backup and NROM
-Supports multiple games on one cartridge
-Has recovery mode to restore cartridge in case of accidental Flash corruption (bricking)