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PostPosted: Wed Jun 04, 2014 12:35 am 
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Anyone here used NesderDC SE for the Dreamcast? It's nice, you can add pictures, NSF, game genie codes, FAQs, and manuals for all the games. I've found though that it's database doesn't have listings for all the games that I have selected (nor the manuals and other extras). Or perhaps it does but only for different versions of the game.
I'm currently modifying it's database but cannot figure out how to produce a CRC of the .nes files. The first thing I did was use a CRC-32 calculator on one game that was known to work but the result of a didn't match what was in the database. Then I learned that it is standard in the NES community to only calculate after the first 20 bytes and so I made a copy and stripped out the first 20 bytes with a hex editor. Unfortunately the CRC result still differs from what is in the database so I'm sure I'm still getting something wrong. I am having difficulty finding any hard data on this, how do I correctly calculate the CRC-32 of a .nes file?


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PostPosted: Wed Jun 04, 2014 1:10 am 
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Silhalnor wrote:
only calculate after the first 20 bytes
16 bytes.


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PostPosted: Wed Jun 04, 2014 1:39 am 
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Oh, well I'd actually tried 16 bytes as well as I had seen someone else reference it at that value. There just seemed to be more consensus in the conversation that used 20 bytes so I assumed that was the true value. But this is what I'm getting at with the lack of hard data, all I can find are brief references that people make here and there.

I tried it again with a different rom just now and stripped out the first 16 bytes. I compared the resulting CRC value backwards and NOTed in case the formatting is different and there is still no match with anything in the database.


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PostPosted: Wed Jun 04, 2014 1:55 am 
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Are you using the correct CRC-32 polynomial?

The crc32s in NesCartDB are the same as the one that pkzip uses, but I don't know if that's also true for nesderdc.


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PostPosted: Thu Jun 05, 2014 11:29 am 
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That must have been it! Thanks! I didn't even know you could change the polynomial and still have an actual standard CRC-32, certainly the CRC generator I was using provided no such options. I pulled the CRC code directly out of some source code that came with NesterDC and I've got a match now. :D I've made it into a working disc too so I've got a complete system going now. Mission Accomplished: I can now play NES on my DC with all the silly features I wanted. There's just something about playing console games on a console rather than my computer. ^^ (Not that I don't have a NES but I'd have trouble finding room for it so it stays in the attic.)

Oh yeah, and if anyone else wants this I guess you can PM me, or find my post on the DCEmulation.org forums where I'll be uploading this once I get it packaged up nicely. I'd add it here too but I don't think DC stuff belongs here.


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PostPosted: Thu Jun 05, 2014 12:01 pm 
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It's perfectly fine to discuss NES emulators for Dreamcast in NESemdev.

Three of the five consoles in this generation already have PC hardware. PlayStation 4 is essentially a locked-down AMD laptop, as is Xbox One. The forthcoming Steam Machine likewise uses PC parts. Perhaps the distinct feeling you get by playing on a console is the lack of lag. Desktop operating systems tend to be designed for flexibility rather than getting latency down to the tens of milliseconds.


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PostPosted: Thu Jun 05, 2014 1:44 pm 
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Ah, well maybe I'll post it here too.

They use PC hardware? That sounds boring. I've read about the PS2 Emotion Engine, that chip was really cool in it's novelty to me. Sometimes I think it would be cool to write something for it but I don't really have anything worth doing on the PS2. On the Wii maybe... that interface opens up lots of opportunities.

Wait... could I buy the right AMD hardware and run the PS4 BIOS on it and play PS4 games that way? That would be amazing. It would probably need a bunch of alterations but if that's workable then that would be amazing to do.


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PostPosted: Thu Jun 05, 2014 2:47 pm 
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Silhalnor wrote:
could I buy the right AMD hardware and run the PS4 BIOS on it and play PS4 games that way


Not a very easy task. There is no benifit to this over buying a PS4, if your goal is to play PS4.


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