21 Pin Systems Universal with MODs?


Staff member
Hey guys,

I was wondering if anyone could tell me if there was any 21 Pin Saturn's produced which were not compatible with current 21 Pin mods. I'm assuming all mods work on Asian region systems, but you need to change the switch on the board to make it work with US models?

Thanks for your time,
Funny you should post this...

I don't know about over seas...but I have appear to have a model 3 saturn that was produced in Jan. 97. This saturn features a Sanyo CD drive versus the JVC that my other model has. Also the ribbon cable from the CD Drive to the Saturn main board has a board between it that states "PC BOARD TRAP SATURN". There is also quite a few other differences as well on the main board. Long story short...I was told this was a late model saturn that was designed with Anti-Modding behind it. You can't mod it in other words. I was also told that it was possible to mod this model...but I could never find anybody who knew the procedure for doing so. In the end...I found another Saturn Aug 96 Model 2 that didn't containg this trap board on it. It's been running great with it's mod board now for just over a month.
You beat me to it, CrossBow. But then I found out about that model from you. :p

(Edited by Shentar at 5:33 pm on Dec. 4, 2001)
Quote: from Trenton_net on 6:17 am on Dec. 5, 2001

Hey guys,

I was wondering if anyone could tell me if there was any 21 Pin Saturn's produced which were not compatible with current 21 Pin mods. I'm assuming all mods work on Asian region systems, but you need to change the switch on the board to make it work with US models?

Well, the Modboards from Lik Sang sure work with Australian (and so I assume Euro) Saturns.

When you talk about changing the switch, are you refering to the solder bridge on the modboard or the country jumpers on the Saturn board?

The solder bridge is model specific, although no one seems to know which corresponds with which. I'm pretty sure that you don't need to change any jumpers on the Saturn's board though. I just soldered the signal wire and the power source and away I went.

Just lucky I suppose :)
So does that mean if you have a White saturn or something you still might need to do the soder mode switch deal? Im not sure, but I was under the impression only Non JAP/CN systems needed the soder points to be changed, and that if you had one of the JAP/CN models, you can just plug and go.
What do you mean by 'solder mode switch deal'?

Are you talking about the solder bridge on the modboard or counrty jumpers on the Saturn board?

As I said, I don't know if you need to change the solder bridge on the modboard. Try it as is and see for yourself.

As for the country jumpers, you only need to put in a switch mod there if you want to play games from other regions, but don't have a cart that gets around region lock out or can't use Satconv.
nice try Mega..but trust me..it is more than removing the trap board...

The CD drive doesn't even have either of the two chip types for soldering the timing wire to..in fact...on that saturn..none of the chips are on the top...they are all on the underside of that cd drive assembly...

Also there is another trap board installed that is more complex on the main saturn board itself. Sega actually removed one of the Motorola 68000 chips (the one in the lower left corner of the board...) and that is where this new trap board sits. It has several trace wires soldered to various points on the saturns main board. All of this was done by Sega and their name is printed all over these trap boards...

I feel it can still be modded...but the traps have to be defeated first...and that is what no one has been able to tell me about.
I thought the Saturn only had one Motorola 68EC000 and that was a sound processor.

Odd thing to remove...
Both of the Saturns I've seen only have one 68EC000 as well, and it is the sound subsystem CPU, so if they removed it they would have had to stick a 68EC000 core somewhere else for t to even have a chance of being compatible. Anyway, I've heard that modboards will work on Saturns with that "trap" board, *if* the modboard is installed between the trap board and the mainboard (rather than between the trap board and the CD reader).
Well..I could be wrong about the chip removal..but on my other Model 2 there is a very large square shaped Motorola chip there..and I could've sworn it said 68000 on it. That same location is where the 2nd trap board is installed on my later model saturn that has the trap board in it.

ExCyber, you know you may have something there regarding the installation of the modboard between the trap board and the main board. But there is still one major problem with this still:

Since the modboards has two wires...where do you solder the timing wire for the modboard? This trap board model Saturn I have uses a Sanyo CD Drive Assembly...and the chip either 32pin or 64 pin for the timing wire to attach to...simply isn't there on the front top side. I am sure there is a drive controller chip still being used...but no one I spoke with knew where it was or where the mod board needed to have it's timing wire soldered. So in the end I dug back into my pockets and got another much easier to mod model 2 saturn from Aug 96 for only 10 bucks...and haven't looked back since.

So if you can tell me where the timing wire goes on those trapped saturns...then I will most likely give it another try and then provide some documentation on how to mod this particular model that has as yet...not appeared online that I know of.
thinking about it, the instructions i saw with the pc trap board didnt require a timer wire, just the +5v

unfortunately i dont think that type are available anymore

You have to provide me with a link for these instructions!!!

Everyones I have spoken with stated to me that they thought it was possible to mod a PC trap board saturn...but didn't know how.

Also your talking about the single wire Modboard that has the timing circuit buit onto it. They still make them as sometimes a person will get the single wire over the double wire whenever they order. However, most places will not let you specify. But I think the timing circuit would be easy to make. Afterall the same boards are used, they are just missing the components needed for the timer.

Oh well, Mega please provide a URL or whatever it was that you saw regarding the modding of trapped saturns.

below is the important bit of the page

Update: A correspondence of mine allowed me to help him install the 9.5 chip in his newer Saturn (actually, a very new model...manufactured in February of 1997). After opening up his Saturn, I found a small mini board attached in between the CD-R OM drive and the main PC-board. The board was labeled "PC-Trap". Apparently SEGA has added it's own little MOD chip, perhaps to confuse would-be MODders from MODding their Saturn to play HK and copied games. But from fumbling about trying to figure out what the #### this board actually accomplished, I failed to see its usefulness: When I removed the board, and directly connected the CD-ROM to the motherboard, I could still run games normally (original games, of course). So I tried replacing the board with the MOD chip and low and behold, the system worked normally, now booting-up HK and copied games! Then I also tried re-connecting the PC-trap board and the MOD chip together. When I placed the MOD chip in between the CD-ROM drive and the PC-trap bo ard, the system failed to recognize the HK CDs. When I placed it in between the PC-trap board and the motherboard, then it could read both originals and HKs! Very strange. So the moral to this story is that the PC-trap board serves no useful purpose bu t to discourage MODders into thinking that the MOD chip cannot be installed in the newer Saturns.

Another thing that I found out when I was installing this chip into his new Saturn, was that the 9.5 chip didn't need to be modded like I mentioned within this website (ie. The A, B and C jumpers need not be shorted like I had imagined). The MOD chip had already been shorted with the B and C points connected...the wrong configuration for the newer Saturns after August of 1996. But the chip still worked! Then I tried desoldering B and C and soldering together A and B (like it should be) and the chip stil l worked. So whatever solder ing these two points together means is also a mystery to me. But the only draw back with this chip is that you must have the CD drive door closed whenever you startup the system. If the drive door is not closed, then HK CDs cannot be read...it's like the chip was never installed. With the drive door closed at startup, it's possible to switch games as you like and the MOD chip works norm ally. Please keep this in mind if you are installing a 9.5 chip.

(Edited by megametalgreymon at 3:22 pm on Dec. 9, 2001)
Well, that does indeed explain how it is done. Problem is your right those instructions were done with the older 21pin boards containing the timing circuit on them. But all the newer ones do not have this Timing circuit and rely on the CD timings coming straight from the CD Driver controller chip. Hence all the Mods you get now for the most part are 2 wires to be soldered. The +5 volt lead and then the other usually Blue or green to be placed on the pin on the CD controller chip to read the timings from.

So the real question now...is what is missing on the newer ones that can be added so that the timing wire isn't needed. Or...where is the timing pin to solder the wire to on these newer models utilizing Sanyo Drive assemblies?

Oh well...this mystery may never be fully solved. I suppose the actual number of Saturns out there with the "PC Trap" board installed is so few and semi rare that no one has really taken the time to check them out.

Wish I knew how myself, as I would be more than happy to wire it up and get it working with that unit as well. Heck I would be willing to add the components needed to the Mod board if I can figure out what it needs. I know there is a cap missing...but I am not sure what else. Probably a crystal Ocsillator for the timing..and something else.

I'm looking into adding components to a modboard, but I'm having trouble finding the 74HC04 as surface mounted, let alone the 8.467MHz crystal. When I finally get those, then all I have to do is solder some surface mounted components on. Easy, er, maybe ;)