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1. NO BLATANT PIRACY. This includes reproducing homebrew less than 10 years old, with the exception of free software.
2. No advertising your reproductions, with the exception of free software.
3. Be nice. See RFC 1855 if you aren't sure what this means.



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PostPosted: Sun Jul 03, 2011 6:20 pm 
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I am kinda confuse about some of the RetroZone repro like Splatterhouse and SMBj2 The lost level. I was under the impression that they were just using the MMC3 mapper hack version of the game and kinda figured out how to reproduce the MMC3 function wit ha CPLD or something which would make them able to reproduce those game without using a donor cart. But then I read that piece of text kinda while browsing which kinda puzzled me:

Quote:
Much more than a reproduction, this original game cartridge is built using all new parts. No donor carts were harmed in the making of this game. This is not a mapper hacked version so there are no graphical glitches.


Now I figured that SMBj2 could just use the rom from the pirate famicom cart and a reproduction of the primitive TTL logic chip based mapper of said pirate FDS-to-Famicom cart conversion but I am at a lost for Splatterhouse... Any of you know how it could be possible without using the mapper hack?


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PostPosted: Sun Jul 03, 2011 7:09 pm 
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I was under the impression that the reproduction of SMB2 (J) used a CPLD implementing a minimalist subset of FDS.


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PostPosted: Sun Jul 03, 2011 7:21 pm 
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Wouldn't it be much more work than using the pirate rom? I had the cart a few year ago and it didn't require much to run the game. If they were to use a CPLD to run a subset of FDS, wouldn't we see the ''Now Loading'' message typical of FDS game at some point? That would be a way of finding out but I don't have any of those cart unfortunately and was just curious about the technical part of some of those cart. I got to say I am happy to see they found a way of doing what they do without butchering cart but I would also like to see PCB scan of some of their cart :) (specially the Nintendo Campus Challenge cart). But Splatterhouse is puzzling, they had to use the MMC3 hack, or is it possible they implemented the Namco 106 in a CPLD? I was under the impression that mapper reproduction was a very tough and long process ant not yet possible...

Edit: Here it is, Kevin actually have reverse engineered the same cart I had before http://kevtris.org/mappers/single_pirates/BTL_SMB2jB.html If they really did that, I wonder why bunnyboy didn't look too interested in reproducing bio miracle bokutte upa using the reproduced circuit of my pirate cart that were using TTL logic...


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PostPosted: Sun Jul 03, 2011 7:41 pm 
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SkinnyV wrote:
or is it possible they implemented the Namco 106 in a CPLD? I was under the impression that mapper reproduction was a very tough and long process ant not yet possible

Where'd you get the impression that Verilog code for a CPLD-based ReproPak is "a very tough and long process" compared to the existing code for a PowerPak?


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PostPosted: Sun Jul 03, 2011 8:12 pm 
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tepples wrote:
SkinnyV wrote:
or is it possible they implemented the Namco 106 in a CPLD? I was under the impression that mapper reproduction was a very tough and long process ant not yet possible

Where'd you get the impression that Verilog code for a CPLD-based ReproPak is "a very tough and long process" compared to the existing code for a PowerPak?


Hehe Silly me, I kinda forgot about the PowerPak:) I was refering to reverse engineer and copying a chip to a CPLD was long and tedious. Are the mappers from the powerpak simulated with verilog code? Pardon my ignorance and my lack of knowledge of how the powerpak mapper system work but I didn't think that the FPGA in the powerpak was reconfiguring itself to mimick mapper. I know it was used to make it compatible with different mapper using a mapper file directory. I guess my question is, does the FPGA load mapper file after rom selection and replicate it in verilog?

Also, do you believe recreating a subset of the FDS for a CPLD would be easy? Now that you mention the powerpak, I saw it was supporting FDS game (never stayed too much up to date on the powerpak), I supposed they did something similar to what you are referring to in order to have FDS support?


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PostPosted: Sun Jul 03, 2011 11:35 pm 
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Implementing mappers in a CPLD is not exactly special. Anyone with the knowledge needed could do it. Splatterhouse does not use a terribly complex mapper. The FDS I'm not sure about as no matter what it's still a hack.


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PostPosted: Mon Jul 04, 2011 8:47 am 
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That's pretty cool, I tought it was a big undertaking to reproduce a mappers with CPLD, but then again my knowledge of CPLD and FPGA are limited to knowing what they are, how to use them and how hard it is to use them is beyong me. I was planning to try it out one day seeing as they are getting so cheap. Do you know if there's any verilog code for nes mapper available? Is it possible in any way to use the mapper pack for the powerpak to reproduce mapper? I would suppose it's not possible but since I really don't know how the powerpak mapper compatibility fiel work, I figured I would ask.


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PostPosted: Mon Jul 04, 2011 12:03 pm 
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I don't think the mapper files for the FPGA would be useful for a CPLD. However I think the source code (if that's the correct term) for those mapper files could be adapted for use in a CPLD.

Most mappers are not terribly complex. Sure there are ones that are alot more work though. For example any mapper with behaviors other than mapping memory like MMC2's CHR Bank Switching on certain PPU reads is a bit more tricky. Then mappers with IRQ generation like MMC3's scanline counter. Then you have mappers that provide extra sound channels and finally the beast that is MMC5 which does a million things compared to other mappers.

I think it's wrongly assumed by many that just because RetroZone doesn't offer repro PCBs for MMC3 or other mappers that it isn't possible or they would have trouble doing it. This is not true.

For that matter, anyone that can design a PCB and figure out how to design for a CPLD could make their own MMC3 production boards. In my opinion the hardest part of doing so would be getting IRQ behavior done. Or atleast done right. If you were going to produce anything other than bootlegs though, it might be in your interest to see about making an operationally compatible Scanline Counter IRQ but actually use a method that would not interfere with using Sprites from both sides of the Pattern Tables.


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PostPosted: Mon Jul 04, 2011 1:13 pm 
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Thanks for you reply, it was very informative! The mapper specific info is past my level though but it was till very interesting. CPLD and FPGA seem so fun to play around and I wish I could use them. I wonder how hard it is to start playing around with them but I figured you need to know how to program in order to do anything.

Also I suppose that RetroZone are not selling MMC3 repro board as most people would likely buy the board at a lower price and add the rom themself insted of buying the full game reproduction at full price...


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PostPosted: Mon Jul 04, 2011 3:59 pm 
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It could be because there isn't a homebrew game that actually needs MMC3 yet. Or at least that's the impression I got in my discussion with bunnyboy.


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PostPosted: Mon Jul 04, 2011 4:10 pm 
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MottZilla wrote:
I don't think the mapper files for the FPGA would be useful for a CPLD. However I think the source code (if that's the correct term) for those mapper files could be adapted for use in a CPLD.

Most mappers are not terribly complex. Sure there are ones that are alot more work though. For example any mapper with behaviors other than mapping memory like MMC2's CHR Bank Switching on certain PPU reads is a bit more tricky. Then mappers with IRQ generation like MMC3's scanline counter. Then you have mappers that provide extra sound channels and finally the beast that is MMC5 which does a million things compared to other mappers.

I think it's wrongly assumed by many that just because RetroZone doesn't offer repro PCBs for MMC3 or other mappers that it isn't possible or they would have trouble doing it. This is not true.

For that matter, anyone that can design a PCB and figure out how to design for a CPLD could make their own MMC3 production boards. In my opinion the hardest part of doing so would be getting IRQ behavior done. Or atleast done right. If you were going to produce anything other than bootlegs though, it might be in your interest to see about making an operationally compatible Scanline Counter IRQ but actually use a method that would not interfere with using Sprites from both sides of the Pattern Tables.


SkinnyV wrote:
Thanks for you reply, it was very informative! The mapper specific info is past my level though but it was till very interesting. CPLD and FPGA seem so fun to play around and I wish I could use them. I wonder how hard it is to start playing around with them but I figured you need to know how to program in order to do anything.

Also I suppose that RetroZone are not selling MMC3 repro board as most people would likely buy the board at a lower price and add the rom themself insted of buying the full game reproduction at full price...


This is really my goal with the NESDEV1 dev cart: http://nesdev.com/bbs/viewtopic.php?t=7656&start=180

You're right about needing the source code MottZilla for anything from the powerpak to be useful for someone like us putting mappers onto a CPLD. The only one I know of currently is qbradq's source code for the FME-7. He posted it up on the wiki, but no ones had the hardware to test it out yet.

I want to make it so it's hardware is capable of replicating the MMC3 plus room for extras. I want it to be easy to program the CLPD via USB cord and free software. The idea is we could all share the source code on a wiki or somewhere that would allow people to use mappers others have created, modify someone else's work, or brew up your own complete mapper. But also allow quick programming of the "ROMS" for testing games on the console with similar hardware that would be used for repros.

It won't have MMC5 capabilities, because that would require a FPGA but a future version could.

It's challenging to get all the parts together as an individual especially if you're not learned up on hardware design which is the case for a lot of developers here. My goal is to make the hardware so the only thing to do to make it better is develop code that implements it and have everyone share :)


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