Page 1 of 9

EMUya - A emulation store for homebrew NES development

Posted: Fri Feb 15, 2013 10:33 pm
by Zelex
Hi all!

I'm putting together an emulator for the Ouya and this is a call out to all indie NES devs. I modeled the emulator after nemulator (cause its design is awesome!)

I had a crazy idea that instead of selling the emulator itself, it could be a marketplace for indie NES games.

If you guys think this is a good idea I can add an purchase option to the emulator to unlock your games (which I will store in an encrypted format).

The only rule for Ouya is that you have a demo that people can play for free before purchasing.

Let me know if your interested in selling your game to a large audience! :)

Best,
Jon

Image

Re: EMUya - A emulation store for homebrew NES development

Posted: Fri Feb 15, 2013 10:44 pm
by blargg
If people made games for purchase on it, it seems that it wouldn't be a NES, just a NES-like platform. The game would have to work properly on your emulator, since that's what people are paying to play it on, so any differences from NES would have to be accommodated by the games. And you could't fix emulator bugs since it would break previous games (unless you are able to tie each game to a specific emulator version). Even ignoring these unwanted sources of inaccuracy, since the emulator would be the only target, you'd want to add things to make split-screen easier, give more CPU time, etc. These are easy to do and make game development simpler.

It would be an interesting way to sell homebrew NES games without high production costs and without worries over unwanted sharing. In fact, worries over unwanted sharing would actually encourage making the emulator work somewhat differently than NES to prevent playing any leaked game ROMs on NES emulators or NES hardware. Simple approaches would be to change the memory map, e.g. RAM in a different place, PPU/APU registers elsewhere.

Re: EMUya - A emulation store for homebrew NES development

Posted: Sat Feb 16, 2013 12:14 am
by Dwedit
If there are desirable games, and an esoteric mapper, people will emulate it. (see Super Mario World or Final Fantasy 7).

Re: EMUya - A emulation store for homebrew NES development

Posted: Sat Feb 16, 2013 6:12 am
by tepples
blargg wrote:If people made games for purchase on it, it seems that it wouldn't be a NES, just a NES-like platform. The game would have to work properly on your emulator, since that's what people are paying to play it on, so any differences from NES would have to be accommodated by the games.
Using an existing well-tested emulator core in NDK would help, as long as the emulator is at least as accurate as a common famiclone. I imagine the idea is that some games will be made available on Ouya and on an NES cartridge, and someone who owns both an Ouya and an NES might play the free demo on the Ouya Store and decide to buy it on cartridge.
And you could't fix emulator bugs since it would break previous games (unless you are able to tie each game to a specific emulator version).
Hence the different IOS binaries in the Wii system software and the emulator binaries in Virtual Console.
Simple approaches would be to change the memory map, e.g. RAM in a different place, PPU/APU registers elsewhere.
Hence the palette rearrangement in the 2C04 and the swapping of addresses of PPUCTRL/PPUMASK in the 2C05. "RAM in a different place" wouldn't work because the 6502-derived core in all 2A0x family CPUs depends on having the direct page at $0000-$00FF and the stack at $0100-$01FF.

Of course this whole plan would need to be modified if the Ouya Store distribution agreement has a non-compete clause like that of the App Store and Google Play Store that prohibits applications from acting as app stores themselves. In such a case, you'd need to distribute your emulator as a tool to package a single ROM, much like Virtual Console for Wii and Macifom for iOS.

Re: EMUya - A emulation store for homebrew NES development

Posted: Sat Feb 16, 2013 7:33 am
by James
Zelex wrote:I modeled the emulator after nemulator (cause its design is awesome!)
8-)

Re: EMUya - A emulation store for homebrew NES development

Posted: Sat Feb 16, 2013 2:40 pm
by Punch
An idea that I had not long ago (when I was thinking about XNA only to learn computer generated sounds is a no-go on the platform) was to add "achievement" support by watching a ceirtain RAM address... when the ROM program sets a watched flag to true, the emulator app must acknowledge it and display "you have unlocked a trophy: [TROPHY TITLE]" (search the respective trophy ID/Title on the emu's internal database) and then save it on a separate file.

Re: EMUya - A emulation store for homebrew NES development

Posted: Sat Feb 16, 2013 2:49 pm
by tepples
Punch wrote:An idea that I had not long ago (when I was thinking about XNA only to learn computer generated sounds is a no-go on the platform)
They finally fixed that in XNA 4.

Re: EMUya - A emulation store for homebrew NES development

Posted: Sat Feb 16, 2013 3:59 pm
by zzo38
Zelex wrote:If you guys think this is a good idea I can add an purchase option to the emulator to unlock your games (which I will store in an encrypted format).
What if I make a game and want you to not make it encrypted, rather make it decrypted once purchased? It seems not so useful if you cannot copy it to a different system to play or modify. (Digital signature may be useful, though, in order to ensure working of achievements and so on.)

Re: EMUya - A emulation store for homebrew NES development

Posted: Sat Feb 16, 2013 4:51 pm
by Zelex
zzo38 wrote:
Zelex wrote:If you guys think this is a good idea I can add an purchase option to the emulator to unlock your games (which I will store in an encrypted format).
What if I make a game and want you to not make it encrypted, rather make it decrypted once purchased? It seems not so useful if you cannot copy it to a different system to play or modify. (Digital signature may be useful, though, in order to ensure working of achievements and so on.)
Sure that can be an option, np. I think the folks who sell cartridges only would however prefer the ROM didn't go into the wild though.

Re: EMUya - A emulation store for homebrew NES development

Posted: Sun Feb 17, 2013 12:43 pm
by tepples
Such an option might be called "Export Game to CF for PowerPak". In that case, I wonder how easy it'd be to watermark the ROM on decryption by adding obfuscated copies of the IMEI or other buyer-identifying information in various parts of the ROM. For example, it could be hidden in an unused tile, a grass tile, etc. The buyer's name could be stored in the title screen. That way, a decrypted ROM inappropriately distributed to the public could be traced to the buyer. Apple does this with DRM-free M4A tracks sold through the iTunes store.

Re: EMUya - A emulation store for homebrew NES development

Posted: Sun Feb 17, 2013 3:10 pm
by Sik
Zelex wrote:I had a crazy idea that instead of selling the emulator itself, it could be a marketplace for indie NES games.
Couldn't this potentially put you into trouble, making a store within a store? Sure, I guess you could argue it's the IAP of the emulator, but being full-blown games I'm not sure the guys at Ouya would be happy about the idea.

It'd make more sense to just sell each game separately directly on the Ouya store and use the emulator as the means to get it running on the Ouya. You could even easily customize the interface of the emulator to each game.

Re: EMUya - A emulation store for homebrew NES development

Posted: Sun Feb 17, 2013 3:17 pm
by 3gengames
Put ads in the emu that are downloaded off a server that show the other games, new releases, etc. So they're linked but separate entities.

Re: EMUya - A emulation store for homebrew NES development

Posted: Sun Feb 17, 2013 3:43 pm
by Zelex
Sik wrote:
Zelex wrote:I had a crazy idea that instead of selling the emulator itself, it could be a marketplace for indie NES games.
Couldn't this potentially put you into trouble, making a store within a store? Sure, I guess you could argue it's the IAP of the emulator, but being full-blown games I'm not sure the guys at Ouya would be happy about the idea.

It'd make more sense to just sell each game separately directly on the Ouya store and use the emulator as the means to get it running on the Ouya. You could even easily customize the interface of the emulator to each game.
People do this all the time on iOS and Android, I don't see why they would have a problem as long as they get their cut. If we tried to cut them out, they probably would not be very happy about it.

Also, I'll let you choose how much you feel the store is worth to you. So, if you want nothing to go to the store, the cut is between you and Ouya only. I think that is fair given all possible outcomes.

Re: EMUya - A emulation store for homebrew NES development

Posted: Sun Feb 17, 2013 3:47 pm
by Kasumi
That way, a decrypted ROM inappropriately distributed to the public could be traced to the buyer.
I've thought about something like this for selling a plain homebrew rom. When I told someone of that plan, they asked, "Yeah, so you know who did it. Then what?" What can you do as a solo person? Taking them to court is expensive. I mean... you could publicly shame them, maybe get them banned from the OUYA store, but I think that makes you look worse than them and doesn't undo the damage.

Re: EMUya - A emulation store for homebrew NES development

Posted: Sun Feb 17, 2013 4:34 pm
by 3gengames
Put the ROMS online and have it download them from a server just to host them. I'm sure it's a lot harder to extract them if they're not in the file.