Single Switch Region Mod

[cornacchia]

So I found out if you use a DP3T switch, shown here http://www.allelectronics.com/make-a...-SWITCH/1.html , you can wire your genesis to play all regions using one switch. I mapped out how to do it like this:

I hope this helps to anyone, the switch is bigger than one of the smaller switches but if you can find any other DP3T switch. Let me know what you guys think.

[MEGADRIVE Jeroi]

First, All megadrives/nomad/cdx and such, use 2 jumpers Language and Hz

Adding to language +5 will define console to English
Adding to language GND will define it Japan
Adding to HZ +5 will define it to 60hz
Adding to HZ GND will define it to 50hz

All megadrives exept megadrive2 use JP1-2 (Language) and JP3-4 (hz). By default you have traces to them defining your consoles region wich depends on wich region console you have.
Now we can go to to see how you can mod you every Mega Drive/Genesis with just one 3 position switch.

Here are the default Jumper sets for each region of Megadrive/Genesis/JAP Mega Drive:



Mega Drive/Genesis Single Switch Mod 2:

Fist, cut all traces from +5/GND to JP1-4.

Theory note: Devil N has found that when not providing (cutting all traces to 1-4 jumpers) gnd/+5 for the jumper pins JP1-2 (jap/eng) and JP3-4 (50/60),
they will provide by default +5 to the console and console thinks itself as US version. So you can change language and HZ just by providing GND to Jumper pin. The only difference with EU and JP are that EU needs GND to HZ for 50hz and Language needs english +5 but JP needs GND to Language as it needs to be Japanese but HZ is +5 60hz.

This allows wire ON-OFF-ON switch this way:



Here is pohotos mod that I made to one Mega Drive 1:







Note: GND can be taken from any GND spot or pin of the Mega Drive/Genesis motherboard.

Mega Drive 2/Genesis 2 Single Switch mod:

Theory is same as for MD1, but MD2 needs additional steps as it don't have the same jumper set as MD1 so modding MD2 single switch is a bit harder.
Mega Drive 2 uses different jumpers and they are called Pin107 (language) and Pin46 (50/60hz).

First lift pin 107, as lifted it is defaulted to +5:



Cut this trace, it provides GND to pin46 so when this cut, pin46 defaults to +5:



Wire 107 pin. If used 3 color cable (red,green, multi) I would use red here:



Wire Green to JP3 pin 46 and Multicolor to GND of jp3:



The wire cables to ON-OFF-ON switch: green | multi | red:

[TmEE]

Devil N (IIRC) has a very neat and simple solution in his signature

[sean]

With this modding a genesis will be much easier to place the switch.

[MEGADRIVE Jeroi]

I think that people shoould remove the 2 switch mod guides because it is very doable with only one switch. 2 switch mod is old news and makes people to buy to switches where 1 could be used very easilly.

[dadou]

how can i mod the console with one switch ON-OFF-ON but not with the jumper but with the 46 and 107 pin ?

[64k]

what would happen if I was to cut ALL the traces without soldering or connecting anything?

just literally cut it?

[MEGADRIVE Jeroi]

what would happen if I was to cut ALL the traces without soldering or connecting anything?

just literally cut it?

If you mean you cut the jumper traces? if you cut them, COnsole thinks itself as US version, providing +5 for bioth jumpers. The US console had jumpers for I DONT KNOW WHY the reason because without jumpers, it is GENESIS or US version anyway.

[64k]

yeah sorry.

If I run a knife and severed all;

jp1
jp2
jp3
jp4

without connecting ANYTHING, the system thinks its an American Unit @ 60hz ?

the origional system is a PAL unit.

[MEGADRIVE Jeroi]

yeah sorry.

If I run a knife and severed all;

jp1
jp2
jp3
jp4

Yes, but dont cut connection from 1-2 and 3-4. When you cut the traces to 1-2 and 3-4 then YES, your pal megadrive thinks itself as US 60hz model or English 60hz model. You can simply test it. When installing switch, after you have cut the jumper traces, fire up the mega drive. It should now run in 60hz mode.

[dadou]

if i'm doing something like that for my Pal MDII it will work?

[MEGADRIVE Jeroi]

if i'm doing something like that for my Pal MDII it will work?

You need to still cut that trace from somewhere of the md2 mobo. The jumper mod is different for md2.

[dadou]

yes this one pin 46 : http://www.segakore.fr/images/articl...tch_md2_07.gif
and this one pin 107 : http://www.segakore.fr/images/articl...tch_md2_06.gif

if i do this it will work fine?

[MEGADRIVE Jeroi]

When you lift 107 and then cut the trace as mmmonkey website says, then fireup md2, it should be in 60hz if it will work.

Then putting 107 and jp3 to switch and gnd to middle OFF position should work.

But if md2 dont act as US console when jumpers are not connected, then md2 need ON-ON-ON switch.

Remeber to report here about your experiments, if you can do the the ON-OFF-ON mod for MD2 then please report.

[dadou]

if i cut this one http://www.segakore.fr/images/articl...tch_md2_07.gif the MD is only USA one (genesis)

i don't have jumper in my MD i need to isolate the 107 pin and provide it 0V

so my circuit should work no?