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Saturn Mod chips...EXACTLY how do they work?

Shrewd_user - May 19, 2003

		Shrewd_user		May 19, 2003
			Could someone please explain to me exactky how sega saturn mod chips work(21 pin). i'd like to be able to replicate them using a pic16f628 or similar(www.microchip.com...) a little help please?

		Shrewd_user		May 19, 2003
			For Example what is the pinout of the 21pin ribbon cable? and what is sent when the sega is reading the protection ring and what is the propper reply(in binary)? is it serial or parallel?

		antime		May 19, 2003
			The best info I've seen on pinouts etc. can be found in these schematics... (though there's no guarantee they're totally accurate or that they correspond to your model Saturn). As for the data sent over the cable, I guess your best bet it to hook the Saturn to a logic analyzer or scope or somesuch. AFAIK this info hasn't been released onto the net.

		Shrewd_user		May 19, 2003
			Ummm.....yea, but i dont know japanese.

		Curtis		May 19, 2003
			Live a little - click a few links. I think what you are asking for is quite complicated. You definately need to use a logic analyser to discover the output of the various devices and attempt to reverse engineer from there. I can't think of any other way of obtaining that information - as antime says, the information is (understandably) sparse. Do you mind if I ask you why you want this information?

		Shrewd_user		May 19, 2003
			well...im trying to make a mod chip 'cos they dont sell them here in australia anymore. actually do any of you have the schematics for one? thanx.

		mal		May 19, 2003
			Another Aussie! Cool. What sort of Saturn are you wanting to mod? If it's a 32 pin unit, just order one in from either Lik-Sang... or Lan-Kwei... as they post to Australia.

		Shrewd_user		May 19, 2003
			Umm i think(pretty sure) it's a 21 pin saturn.

		mal		May 19, 2003
			Don't wory about me, I'm just making assumptions about what you know... Does the CD board of your Saturn have a rectangular 32 pin IC on it? Or does it have a square 64 pin IC pic? If it's got the 32 pin IC any 21 pin mod should work. If it's got the 64 pin IC gamegizmo mods did work, but they don't sell them any more. At this point in time, no other mods are guranteed to work; there seems to be some incompatability. sigh BTW, where's the Saturn section gone at Lik-Sang? :confused Don't tell me that they're not doing Saturn mods anymore...

		AntiPasta		May 19, 2003
			maybe have a look in the Otaku corner? I also heard modchips are easy to find in Brazil, is that true?

Yceman

May 19, 2003

	
	
		
		
			Originally posted by AntiPasta@May 19, 2003 @ 10:53 AM



 maybe have a look in the Otaku corner? I also heard modchips are easy to find in Brazil, is that true?

Well, since I live in Brasil I guess I can answer this

A few years ago, when the Saturn was still alive, it was very easy to find modchips for it, but now I guess it's almost impossible, at least in most towns. Maybe the only place that has it is Santa Efigênia in São Paulo, but I can't give you more info about this place since I don't live there.

		Pyrite		May 19, 2003
			Lik-Sang does not have saturn mod chips at the moment so it seems <_< I really should buy a couple mods before its too late.

		gameboy900		May 19, 2003
			Making your own mod chip would be very difficult. Not really because you can't replicate the layout of the board but because you need a pretty complex program on it that no HK maker is quite willing or could give half a fuck about to give away. Also from what I hear you can't actually read the code on the chip back either due to the design of it.

		Curtis		May 19, 2003
			Yeah I'd agree with that last statement GB. I've had a brief glance at the specs for some of the onboard IC's - they seem to specify some kind of write once, read never mechanism if I understood the information correctly.

		antime		May 20, 2003
			Well, if you have access to the right equipment you might be able to strip the chip package and manually flip the read-protect mechanism. Definitely not something you could do in your kitchen, but has been done (some PSX/PS2 modchip was verified to contain stolen code this way, there was a nice webpage with photos up at some time).

ExCyber

May 20, 2003

	
	
		
		
			Well, if you have access to the right equipment you might be able to strip the chip package and manually flip the read-protect mechanism. Definitely not something you could do in your kitchen, but has been done

As a matter of fact, it seems that this sort of thing is what the infamous bunnie... is doing as his occupation... now.

	
	
		
		
			you need a pretty complex program on it

It's not clear that the program itself is complex (low-end PICs don't make happy homes for complex programs), but the process needed to obtain the necessary information to write it probably is tricky for anyone other than a professional electrical engineer or someone with similar diagnostic knowledge and equipment.

	
	
		
		
			I've had a brief glance at the specs for some of the onboard IC's - they seem to specify some kind of write once, read never mechanism if I understood the information correctly.

The main components, at least on most mods, are a PIC microcontroller and an SPLD. The SPLD probably fits your description better than the PIC, but the reason it looks confusing is that it's not a memory but a way to produce custom logic chips, i.e. the chip contains an array of gates and you "write" it by blowing internal fuses to set up the logic functions you want.