Sega Saturn Single Switch Region/Country Mod

Sega Saturn Single Switch Region/Country Mod

This guide is based on the one here, it allows you change from Eur/JPN/US mode with just a single switch (most guides use 2 switches for this modification). Unfortunately it looks like that site has now gone :-(

There are  many different versions of the Saturn motherboard, so a comprehensive guide would be very difficult.

If you need help constructing the circuit from Mameworld, then here’s a diagram of the Strip/Vero board which I (attempted to!) design.

The basic components are a piece of Vero board (8 tracks tall, 12 holes wide), a 7404 (I keep getting supplied a 74LS04 which works fine) Hex Inverter, 2 1K resistors, some wire and a Single Pole/Double Throw Centre Off switch.

Basic components

Once you’ve cut your board to size, cut along the some of the tracks as shown in the diagram at the top of the page and the following photo.  Some people drill the holes to make them bigger so the break the track, I usually just makes some cuts using a sharp blade, then picks a bit out.

Cut the board

Then prepare some wire ready to join the link points.  I used some legs from resistors used in another mod, and bent them into shape, then soldered them into place and cut the excess legs off.

Links bent to shape

Notice the 3 cuts as per the diagram

Links soldered in, and trimmed short

Links completed

Now it’s time to solder the 7404 Hex Inverter into place, make sure you put it in the correct way around, there is usually an indent and/or a dot showing you which end is pin 1 (a dot on the diagram above).  I soldered all the legs, this isn’t necessary – but it was easier than double checking which legs were necessary.  Find something to rest under the Vero Board to make it level whilst it is upside down (like the resistor shown below).

Hex Invertor in place

Hex Inverter soldered in

Once the Hex Inverter is complete, double check where the two 1k resistors should go, solder them into place and trim the excess leg off.

Resistors in place

Next prepare some wires for the power, strip the wire and tin it (heat the wire up and apply a tiny bit of solder to it). Make sure the wires are long enough to reach from where ever you decide to place this board, to the underside of the Saturn motherboard where the +5V and GND is taken from. Again, solder the wires in place according to the diagram and the following photos. Remember to trim any excess wire from the underside of the board.

Power wires

The second column of holes is used for the switch, cut 3 pieces of wire (make sure they are long enough), and solder them into place on the board, double checking the diagram. The third column of the board is used to connect to the relevant pads on the underside of the Saturn motherboard. Solder all the wires into place, following the diagram and this photo.

Wire locations

That’s the board complete! If you’re also doing the 50/60Hz mod, then you could solder the necessary +5V and GND wires to this board (top row for +5v, fourth row for GND) instead of the Saturn motherboard, you could also power your Saturn modchip from this board as well (a modchip is necessary to play backups).

Prepare your switch by tinning the contacts, be careful – if you hold the soldering iron onto the contacts too long it could melt the plastic, causing the contact to move out of place and be useless. I usually melt a blob of solder on the soldering iron tip, then runs it along the contact quickly. Tin the wires coming from the second column of holes, and follow the diagram and colour coding of the photo’s to solder the correct wire to the correct contact.

Prepared switch

Prepared wires

Completed switch

Completed board

Now it is necessary to take the Saturn apart, take to top off and decide where you are going to mount the circuit board (this is easy as there is loads of room). Then remove the motherboard and look for the necessary pads to solder onto. I’ve performed this on a couple of Saturn’s, they were all VA9 model motherboards – there are lots of different motherboards though, please read the guides on Mameworld and GamesX, this guide only complements them. With the Saturn in pieces decide where you will mount the switch, I decided to use the door for the Battery/VCD Card compartment.

Decide where the circuit will sit

Look for the JP Pads

It is necessary to remove the links from JP7, JP10 and JP12 (on a Euro Saturn anyway, it will be different on Jap/US consoles), soldering the wires is easy, make sure you’ve got the the correct wire soldered to the correct pads – you’ve built the circuit board, so you should now which wire is for JP6/7, JP10/11 and JP12/13. You may want to add a little bit of solder to the pads to make soldering the wires easier, melt some solder onto the wire (tinning) and trim the tinned wire so it’s very short. I must stress that if your board is not a VA9 model, then you must refer to the guides on Mameworld and GamesX to make sure you’ve got the right pads (also, I’ve added some more photos at the end of this guide now).

Pads ready to solder onto

JP pads wired

The photo above shows the pads that you can choose to solder onto. For JP6/JP7 you can solder onto either of the pads highlighted in Red, the same applies for JP10/JP11 and JP12/JP13.

We need to power the circuit board, we’ve already soldered some wires to it, we just need to solder them to the underside of the motherboard then re-assemble, and test it out! Make sure you insulate the circuit board!

+5v and Ground wires soldered

Insulated board in its new home

The completed picture above also includes a Modchip, useful for CDR’s – great for those scratched discs from eBay!

Completed switches

Of course, all credit must go Mameworld for their original guide here (sadly gone!) and GamesX.

If you’re performing this mod before you’ve even got any import games then you can test it by checking the System Settings menu, in the bottom right-hand corner it will have a code that tells you the following info (thanks to chaoticjelly for confirming the codes), of course – the BIOS version part of the code may differ (I don’t think this is on the Japanese BIOS)

Region Code (Video Mode-Region-Bios Version)
Europe PAL-C-V1.01a
USA NTSC-4-V1.01a
Japan NTSC-1-V1.01a

Summary of Components

  • 2 x 1K Resistors
  • 1 x 7404 Hex Inverter
  • Vero Board (cut to 12 holes wide, 8 tracks tall)
  • 1 x Single Pole, Double Throw, Centre Off Switch
  • Some wires!

Extra Photos of JP Points

Forgot to make note of model :-(

First of all, I forgot to make a note of the model number of this motherboard! Ooops, but it was an early Model 2 Saturn, the case had round buttons, and the controller sockets were on a separate board to the motherboard.

JP6/JP7 was on the underside of the motherboard, look around the area where the earth strap for the CD-ROM drive attaches. I had to cut a small link on JP7 (cut it with a sharp blade, cutting through it a couple of times to ensure it was definitely broken), you can use either of the points highlighted in red (these are the common points referred to on the gamesx guides)

Cut the link, suitable pads in red

Wire soldered into place

JP10/JP11 and JP12/JP13 are on the upper side of the motherboard, in the same kind of area, there were links to cut through on JP10 and JP12 (pink lines on the photo below). The common points are shown in red again.

 Model 1 Saturn, 171-7069B MAIN, 837-11892-01:PAL

Again, JP6/JP7 are on the underside of the motherboard near the area that the CD-ROM earth strap screws onto. Red dots show the 2 points you could solder onto, pink line shows where I had to cut a link.

JP10/JP11 and JP12/JP13 – top side of motherboard, same area, cut links and solder to either of the common points (shown in red)!

Very early model with PSU in the lid of the console case. VA0.5

This was a Japanese model, so has different JP points linked up to a Euro console. JP location is on the underside of the console, middle/front.