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Why do so many homebrew games don't have roms?

Question Homebrew Rom

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#51 hizzy OFFLINE  

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Posted Mon Sep 24, 2018 12:15 PM

I buy homebrews from the AA store to help support Atari Age. There are ROMs I play like crazy. I played so much Anguna and Panky the Panda that I wanted to have the game on cart and give something back to the site.



#52 Kosmic Stardust OFFLINE  

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Posted Mon Sep 24, 2018 8:45 PM

Especially graphics can be removed without much knowledge. Watermarks are spread all over the ROM, so it is very hard to remove them sufficiently.

So I buy the game and play it. So what if there's an odd extra pixel in my player's hairdoo not present in the video trailer?

Enemy has pixel removed from foot? Yeah they won't expect the preview video to match thd csrt at all.

#53 Thomas Jentzsch OFFLINE  

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Posted Tue Sep 25, 2018 12:39 AM

So I buy the game and play it. So what if there's an odd extra pixel in my player's hairdoo not present in the video trailer?

Enemy has pixel removed from foot? Yeah they won't expect the preview video to match thd csrt at all.

??? :?



#54 Gemintronic OFFLINE  

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Posted Tue Sep 25, 2018 2:07 AM

So I buy the game and play it. So what if there's an odd extra pixel in my player's hairdoo not present in the video trailer?

Enemy has pixel removed from foot? Yeah they won't expect the preview video to match thd csrt at all.

 

Well, it's a anti hacking/watermarking technique.  Not necessarily something obvious (or not obvious) to the user.  Just something that can be detected once some genius decides to take a pirated ROM and make reproductions. 



#55 John Stamos Mullet OFFLINE  

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Posted Tue Sep 25, 2018 4:00 PM

PCB's have to be populated into cases, labels have to be placed. It's all work that somebody has to do and sometimes it's not worth the hassle.

in that case, release the rom, since they don't plan on making money from selling it at that point.

#56 lingyi ONLINE  

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Posted Tue Sep 25, 2018 6:27 PM

The more I think about it, in this age of anything posted on the internet, it's there forever, the 'artistic' aspect of game development may be a major factor. For many developers, 2600 games are a hobby and like many hobbies, their skills get better the more they do it and sometimes (as a stated before), they don't want their earlier possibly 'primitive' works to be available to the general public. Especially if it may be the first or only introduction to someone of their work, that is not representative of what they're capable of now. 

 

Personally, I'm relieved and satisfied that the ROMs are preserved by Albert and others, perhaps someday to be released with the developer's blessings. 



#57 lingyi ONLINE  

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Posted Tue Sep 25, 2018 8:23 PM

Here's a thought that will likely get flamed to death. What if homebrew ROMs were issued with limited levels or capabilities with those wanting to get the complete ROM having to purchase it through AA. 

 

I use my 2600 primarily for those games I played back then and have more then enough free ROMs to use with my Harmony cart, but would be open to try before I buy homebrews  as downloads for say $5-$10, versus $30-$50 for an actual cart. 



#58 hizzy OFFLINE  

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Posted Thu Sep 27, 2018 7:43 AM

Here's a thought that will likely get flamed to death. What if homebrew ROMs were issued with limited levels or capabilities with those wanting to get the complete ROM having to purchase it through AA. 

 

I use my 2600 primarily for those games I played back then and have more then enough free ROMs to use with my Harmony cart, but would be open to try before I buy homebrews  as downloads for say $5-$10, versus $30-$50 for an actual cart. 

 

Assembloids had a demo rom, which was good enough for me to get a taste of game play. I've always been able to try any game before purchasing. I have a modest collection of 15 - 20 homebrews. I would buy more, but the Canadian exchange is awful right now. 

 

I wonder what the ratio is between downloading and purchasing? Do people end up buying the game if they like the rom?

 

I think the only AA roms that are not available in full are Assembloids and Boulder Dash.


Edited by hizzy, Thu Sep 27, 2018 7:46 AM.


#59 Kosmic Stardust OFFLINE  

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Posted Thu Sep 27, 2018 10:43 PM

Well, it's a anti hacking/watermarking technique.  Not necessarily something obvious (or not obvious) to the user.  Just something that can be detected once some genius decides to take a pirated ROM and make reproductions.

I would suggest making changes to an unused area of rom (for watermarking purposes) that do not "corrupt" the graphics.

Two bytes of data will suffice. To make it more hack proof, two bytes of data in two areas of the rom. Use a random number generator to assign unique values from 0000 to 9999. Encode one of them in binary coded decimal (two bytes), and the other in hexadecimal (two bytes), both with random bit orders. Then create an fake read command that reads the affected areas but does nothing with the data. This will make it difficult for hackers to use an emulator debugger to check for unused address space.

The only way for a pirate to leak the rom without getting caught would be to buy two copies and compare the data. But if you add a checksum to the rom, the hacker has more hurdles to jump through, as editing a single byte will render the rom unplayable. Hacker will have to correct the checksum after editing or figure out how to disable it.

Again, the checksum is not drm, just a safeguard against tampering with the watermark. At this point, most hackers will have given up, and those that are skilled enough to modify the rom and remove the watermark probably will respect the right owners and not do it. Like the one anonomous dude who dumped Boulderdash and did not release it.

#60 Thomas Jentzsch OFFLINE  

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Posted Fri Sep 28, 2018 1:10 AM

I would suggest making changes to an unused area of rom (for watermarking purposes) that do not "corrupt" the graphics.

What makes you think watermarking would influence the graphics (or anything else in the game)? The opposite is true.

 

And what you suggested can be removed (e.g. by me) in 10 minutes. For a watermark, you will need much more than 2 copies to even find the changes. The more watermark spots and bits are used (and 100 or more spots are easily possible, even for a 4K game), the more copies you need to identify the changes. Then that approach alone makes no sense anymore and you would have to disassemble and analyze the code by hand. And even then you cannot be 100% sure that you removed all watermarks. If you didn't find e.g. 10 bits, chances are very good that some of these are set unique for only a single copy sold. Bingo!


Edited by Thomas Jentzsch, Fri Sep 28, 2018 1:10 AM.


#61 Gemintronic OFFLINE  

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Posted Fri Sep 28, 2018 3:23 PM

Pretty much you have to invent a proprietary bank switching scheme and make agreements with emulator authors.  Even after that people will find a justification for "liberating" your work.  Note that I don't think the original poster is in this camp.  They just didn't understand the implications.



#62 Andrew Davie OFFLINE  

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Posted Fri Sep 28, 2018 5:38 PM

Here's a thought that will likely get flamed to death. What if homebrew ROMs were issued with limited levels or capabilities with those wanting to get the complete ROM having to purchase it through AA. 

 

I use my 2600 primarily for those games I played back then and have more then enough free ROMs to use with my Harmony cart, but would be open to try before I buy homebrews  as downloads for say $5-$10, versus $30-$50 for an actual cart. 

 

We kind of did that for Boulder Dash. We released a free ROM with two (or was it three?) levels. It didn't seem to gain much traction. Still took ages to sell the 250 copies. I don't think it's a bad idea, I'm just giving an example of doing what you suggest.



#63 Zonie OFFLINE  

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Posted Fri Sep 28, 2018 8:06 PM

I download the roms. I buy the carts of the ones I really like and will actually play.

 

I have about a half dozen.



#64 Supergun OFFLINE  

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Posted Fri Sep 28, 2018 8:34 PM

.........Pretty much you have to invent a proprietary bank switching scheme.........


...yeah...they did...its called Melody...

#65 Zonie OFFLINE  

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Posted Fri Sep 28, 2018 8:37 PM

If more games were sold like Defend Your Castle: buy the board and labels, (or board only) and put in my own cart, I'd have a lot more.


Edited by Zonie, Fri Sep 28, 2018 8:37 PM.


#66 lingyi ONLINE  

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Posted Fri Sep 28, 2018 11:30 PM

 

We kind of did that for Boulder Dash. We released a free ROM with two (or was it three?) levels. It didn't seem to gain much traction. Still took ages to sell the 250 copies. I don't think it's a bad idea, I'm just giving an example of doing what you suggest.

 

Thank you for the info. 

 

I find it interesting that this model is still alive and doing well on Android and IOS. I wonder what it is that it doesn't work with 2600 games. 



#67 Keatah OFFLINE  

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Posted Fri Sep 28, 2018 11:35 PM

The VCS doesn't have the benefit of a walled garden. And you can't easily (if at all) pirate encoded apps. And then there's communication with the app server - which the VCS also does not have.



#68 Video OFFLINE  

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Posted Sat Sep 29, 2018 2:17 AM

There's also far fewer Atari consoles than Android (which everybody has in their pocket right now) and it's not for sale cheaply or new anywhere, there's a wide selection of Android phones, and other devices you can get new now for under $50.

As for pirating apps:lol: heh, most people I know do just that, which blows my mind as most are free (maybe the pirates lack adds? Not that you can't manually kill those anyways)

#69 Kosmic Stardust OFFLINE  

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Posted Sat Sep 29, 2018 2:21 AM

Pretty much you have to invent a proprietary bank switching scheme and make agreements with emulator authors.  Even after that people will find a justification for "liberating" your work.  Note that I don't think the original poster is in this camp.  They just didn't understand the implications.

 

...yeah...they did...its called Melody...

Pretty sure Melody isn't proprietary as anyone can develop for it. Also Harmony and Stella both support it.

 

"Gentleman's Agreements" type scenarios between emulator developers and game developers will not work for two reasons, one, because most emulators are open sourced and anyone can add features to the emulator by recompiling and creating new forks with the modifications, and two, because the game developers themselves using the custom hardware need emulators with debuggers to test their own code while developing.

 

Developers need certain forks or builds of emulators to allow the testing of proprietary bank-switching schemes. RetroUSB's UN-ROM 512 (Mapper 30) and Memblers GT-ROM (unassigned afaik) for NES both allow optional flash saving and both allow existing discrete mappers to be converted over to them using special tools. Both are fully documented on nesdev so anyone that wants to could write an emulator or flashcart plugin.

 

I do not know if flash saving support would be possible on either the Powerpak or Everdrive due to the fact changes to the ROM need to be written back while the game is already running. No preexisting games behaved in this manner. Even so games that don't utilize flash writes or only utilize them for high score tables would likely be fully playable. FCEU currently employs flash mapper functionality this by generating a save file containing a duplicate copy of the entire ROM, in contrast with FDS games that overwrite the actual ROM file.

 

The public nesdev data fully documents every bankswitch scheme commercially available, and can also be used to dump any game cart with a CopyNES equipped Toaster bank by bank (using peek/poke commands to write data to key bankswitch registers) and reconstructed in a hex editor. I have even poked around in homebrews I own on cart, but I do not share this data publicly, and have little respect for people who dump and publicly release homebrew carts.

 

To argue it doesn't happen would be folly. 



#70 Thomas Jentzsch OFFLINE  

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Posted Sat Sep 29, 2018 2:28 AM

Pretty much you have to invent a proprietary bank switching scheme and make agreements with emulator authors.

At least for Stella it is pretty clear, that this will not happen.

 

Just imagine the extra effort of supporting e.g. 10 proprietary schemes in 10 different (hidden) branches (and only for one person each). Not going to happen.



#71 Kosmic Stardust OFFLINE  

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Posted Sat Sep 29, 2018 2:52 AM

What makes you think watermarking would influence the graphics (or anything else in the game)? The opposite is true.

 

And what you suggested can be removed (e.g. by me) in 10 minutes. For a watermark, you will need much more than 2 copies to even find the changes. The more watermark spots and bits are used (and 100 or more spots are easily possible, even for a 4K game), the more copies you need to identify the changes. Then that approach alone makes no sense anymore and you would have to disassemble and analyze the code by hand. And even then you cannot be 100% sure that you removed all watermarks. If you didn't find e.g. 10 bits, chances are very good that some of these are set unique for only a single copy sold. Bingo!

You are a developer with intimate knowledge of the system. Anyone who shares your level of knowledge is going to be well respected by the community and likewise isn't going to sabotage that respect to pirate someone else's work.

 

Some bum poking around in a hex editor with no knowledge of how to read or interpret assembly could easily make an edit to presumably avoid detection. For instance say he dumps his own game cart, a limited edition NES homebrew #69 / 100, and displays "LE #69" on the title screen. Most NES games which use character data to display text have the first 37 or so tiles reserved for this purpose. 0-9 occupy range 00-09h (this makes it convenient to display the score onscreen using binary coded decimals in ram), then A-Z occupy range 0A-23h, and the space or empty tile is 24h. The bum uses a hex editor to search for the string 15-0E-24-XX-06-09 (XX denotes whatever tile address is reserved for the pound sign), finds a single match, and fills in this data with 24-24-24-24-24-24. Then he saves the ROM and loads it in the emulator. The title screen watermark is now gone, filled in with empty space. Feeling satisfied, he submits the ROM to a piracy site for public dissemination. But the developer placed a second watermark elsewhere in the ROM which identifies the culprit, banning him from future sales and public shaming the forum accounts.

 

This is about my level of expertise. Same with any would be pirate. The visible watermark on the title screen alone would thwart most pirates.

 

This type of title screen modification can also be witnessed on modern 3rd party NOAC ports (example My Arcade Namco or Data East mini cabinets) of popular arcade games where the "Licensed by Nintendo" and copyright year have been removed or replaced with updated license info, as such compilations are often licensed by the 3rd party arcade company but not Nintendo itself. It can be done very quickly with zero knowledge of ASM code. Nintendo did this to it's own Virtual Console titles as well, giving a date range for the copyright year and in some cases updated 3rd party developer info.







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