SegaXtreme

Home	Forums	What's new	Resources

Dumping MPEG Card Bios

Madroms - Oct 12, 2009

< Prev

		Madroms		Oct 31, 2009
			Or, I can use directly the prog written by CyberwarriorX. Does anyone could tell me how to compile it (I only have the saturn orbit installed) and use it with an AR+Comm card ?

		Madroms		Nov 11, 2009
			ok, mpeg bios dumper works. Does anyone know the size of the mask ROM (from Charles MacDonald sattech.txt = Sega P/N MPR-17896-H) ? It seems to be 512k or more (for the jvc 2 card i tested). I don't know exactly as I limited my program to the first 512k. Next time I will burn it, I will be able to check up to 4M and see what will be coming.

		CyberWarriorX		Nov 21, 2009
			The mpeg cart I have (RG-VC2) is 512kb. If you want to verify your's(using a method outside of dismantling your cart), you can just use the bios mpeg rom dumping function to dump the data beyond 512kb and see where it gets mirrored.

Madroms

Nov 22, 2009

		CyberWarriorX said:
		The mpeg cart I have (RG-VC2) is 512kb. If you want to verify your's(using a method outside of dismantling your cart), you can just use the bios mpeg rom dumping function to dump the data beyond 512kb and see where it gets mirrored.

Ok thanks

I will check all of my MPEG cards to see if all of them are 512k.

		Madroms		Nov 30, 2009
			ok, so all of them are 512k (7 versions checked so far). ALso, I try to add the code for reading mpeg files but with no success. Does Yabause can emulate properly MPEG functions if I use the MPEG Bios ? Because I don't want to waste a lot of cds by burning my piece of codes everytime I want to check what I did (and I don't have my complete setup ready for now with AR and such).

		Madroms		Sep 13, 2010
			Bump thread about MPEG Card emulation and Yabause: I tried Lunar MPEG Edition on Yabause with the MEPG ROM but the game didn't work (intro screens showed but nothing after that, just when the MPEG video must start). Does Yabause work with some MPEG games and Lunar is just one that doesn't work ? Or Yabause doesn't have a complete emulation of the MPEG functions ? I don't know any other emu with MPEG support and I want to try making some MPEG videos running on Saturn for my next project. Thanks

CyberWarriorX

Sep 17, 2010

		Madroms said:
		Bump thread about MPEG Card emulation and Yabause: I tried Lunar MPEG Edition on Yabause with the MEPG ROM but the game didn't work (intro screens showed but nothing after that, just when the MPEG video must start). Does Yabause work with some MPEG games and Lunar is just one that doesn't work ? Or Yabause doesn't have a complete emulation of the MPEG functions ? I don't know any other emu with MPEG support and I want to try making some MPEG videos running on Saturn for my next project. Thanks

Yabause has very minimal MPEG card support. It basically will handle communication, etc. but actual MPEG decoding is not being done.

		Madroms		Sep 22, 2010
			Thanks CyberWarriorX. Do you plan to add a better support in the near future ? Or it is not the most important stuff to do next on the emu, thing I can totally understand If you need some card dumps to add some compatibility, let me know.

CyberWarriorX

Sep 26, 2010

		Madroms said:
		Thanks CyberWarriorX. Do you plan to add a better support in the near future ? Or it is not the most important stuff to do next on the emu, thing I can totally understand If you need some card dumps to add some compatibility, let me know.

It was mainly put off due to the legal issues surrounding MPEG and its related patents. Also the last year or so I haven't had too much time to work on Yabause myself and I'm not sure the others really understood the CD Block/MPEG card like I did. I'm sure we'll eventually add support but we may need to use a separate library or something like libmpeg2.

		rorirub		Dec 8, 2013
			A little bump. I've dumped the video cd bios and it seems there are some discrepancies between dumping the chip directly versus how the Saturn reads it. When dumping form the chip, I get some code from 0 to 5000h, and the cart header starts at 5000h. When reading from the Saturn, that 5000h of junk code is at the very end of the carts. This is consistent on every cart I dumped so far. I understand that gets pushed to the end because it is mirrored in hardware and the Saturn most likely reads it with a 5000h offset. But, what is causing this? Is it normal? A feature?

CyberWarriorX

Dec 11, 2013

		rorirub said:
		A little bump. I've dumped the video cd bios and it seems there are some discrepancies between dumping the chip directly versus how the Saturn reads it. When dumping form the chip, I get some code from 0 to 5000h, and the cart header starts at 5000h. When reading from the Saturn, that 5000h of junk code is at the very end of the carts. This is consistent on every cart I dumped so far. I understand that gets pushed to the end because it is mirrored in hardware and the Saturn most likely reads it with a 5000h offset. But, what is causing this? Is it normal? A feature?

Interesting. I wonder if that data is actually something relevant? Perhaps for authentication by the cd block? Since the data is being filtered through the cd block, it's possible it offsets it there. But without sh1 code it's hard to know for sure.

		rorirub		Dec 11, 2013
			If you've dumped your own cart using the Saturn, you can inspect the data from fb000h to 100000h, see if it relevant in some way.

CyberWarriorX

Dec 17, 2013

		rorirub said:
		If you've dumped your own cart using the Saturn, you can inspect the data from fb000h to 100000h, see if it relevant in some way.

About the only thing I can tell is that it's not text or image data. Possibly Code? Or settings?

< Prev