sega saturn 20pin modchip info

Pretty sure I can clone it, I already started a long while back. There isn't a huge amount of motivation to work on it though since modchips are available, and cheap. All of them are just about identical logically so clone one, clone them all.

 

i ment, in what place we need cheat? what signals response for security? can you show me this on the signal diagam?

 

My understanding is that the modchip feeds the system the security ring data giving it the OK to boot the disc as an authenticated original.

 

i know, but what exact, any details, any points in diagram.

i saw there is serial protocol. i suggest CPLD helps capture signals to gpoup and genereate signal for calling mcu, then mcu put or transfer sequence with right code/level to data bus.
i asked cause its not standart prtocol, maybe someone know about it well.

also it is useful if some check what function of pins used in modchips. there are pins for special functions in mcu's - INT, RX, TX, or simple GPIO

 

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I think it's pretty self explanatory but the PIC is used as a lookup table for the security data. Everything is done through GPIO... The PIC at ~2 MIPs is not nearly fast enough to carry out ~8 MHz bus operations on its own so the GAL is configured as a state machine with 4-bit shift register. The multiplexer simply selects between the CD data and faked security data.

 

i saw VA13 scm, its very useful to know right names of signals. very good scheme))

so, may some one can make primitive scheme of mode chip.

 

rob webb new chips



A new version like this is being worked on. It has connectors for 20pin and 21pin. Also has the crystal, so only a 5v wire is needed. I've tested the prototype in the photo on a 20pin V-Saturn and it worked perfect. It needs testing on other Saturn models, then it will go to production in a few months hopefully (robs words)


link to post

http://segaxtreme.net/community/topic/16348-strange-saturn-mod-chip/

 

Eh, it's just a new PCB with the exact same poor design. There are better designs out there with precisely two chips and decoupling capacitors, that's it. A new modchip should at the very least match that old logic--meaning eliminate the '157, it shouldn't have any level-shifting or delay hacks and it sure shouldn't have a redundant oscillator. Using a newer/more available MCU could relax the code as well, but I highly suspect that the code is with the modchip manufacturer, not Rob.

If anyone wants to work on actually RE'ing the modchip let me know. I'm buying an adapter to run test vectors, hopefully I'll be ready to work on it when it arrives in late July.

 

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I'd offer but I'm not sure how much help I'd be.

 

Just putting a note out there if people need help if there having any problems with the mod on a model 2 Sega Style/Racket Boy Chip to fit in a model 1 ill be glad to help theres some problems i ran into and fixed. these problems i ran into that are not on the trouble-shooting page on sega style but was able to fix. You could get one of the Sega style/racket-boy chips and alternate it with a guide from Sega style. i just did my US model 1 Saturn (20 Pin Connector) not too long ago and ran into a couple minor problems. may take some time but it works perfectly in the end. if there's any problems you would run into that doesn't show in the trouble shooting page. just shoot me a pm or post i might be able to help out.

 

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didn't they take the mod-chips off they're catalog due to paypal issues?. i was considering that mod chip as well. but hey if you run into the problem where you can only get a Sega Style/Racket-Boy chip and modding it for a model 1. i can probably help out

 

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I just received a batch of ~22 myself though they're not the same chip as Racketboy (SSIC8B IIRC) or what Robb Webb stocks. Bit more difficult to modify as there is no easy to use guide out there but totally possible.

 

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Full Disclosure: I sell/stock Saturn chips on demand.

Forgive me for saying so, but getting special chips fabricated seems expensive. Especially considering how 20-pin Saturns aren't exactly a big market. If there was big money to be had, they would still be pumping 20-pin compatible units out. I mean, I've seen loads of chips with the 20-pin side left empty. I'm sure it's done for profit reasons, or they would include it for people.

FYI - If he is fabricating chips, I do plan to get more in. As well, I can likely price match any sellers chips (though I never had to, since I beat everyone by a wide margin).

Update: Is there any market for replacement CD-ROM lenses, controller cables (Unwired), power supplies, and such? Or would I be wasting my time on those you guys think? I never get asked about those kinds of things, so I naturally thought they weren’t sellers.

 

Are you kidding ? DO IT NOW !!
Honestly though the main cases of saturn failure are due CD lenses/motor wear. Most of the faulty units sold on ebay or otherwise are due to this issue (and PSU failure as well). Not to mention the 100V - 220V mods that can be done.

There is profit to be made and believe me when I say, go for it.
I know I want some.

 

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