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Super Nintendo Region & Display Mods

  • #1
    Closed Accounts Posts: 33,733 ✭✭✭✭ Myrddin

    Below is the mod procedure for adapting a PAL Super Nintendo to display a choice of 50 or 60Hz, and to make it dual region (PAL or NTSC). The technicalities of the mod are almost identical to the Sega Megadrive mod. A common point is given wither a ground, or a 5v to change the setting.

    In this case, the region lockout chip (CIC), pin 4 to be specific, is lifted from the board and wired to a SPDT switch, with either side having 5v or ground. The display frequency is controlled by the two PPU chips, pin 24 of PPU1 & pin 30 of PPU2. These two pins are wired to the center of another switch, & given either a 5v or ground to choose the frequency.

    While this makes a PAL Super Nintendo almost fully universal, there are still some limits. US NTSC carts are a completely different shape to PAL carts, & as such won't natively fit through the cart slot. This can be solved by either a) adapting the cart slot with a dremel, or b) using a pass through adaptor, which is the better choice as it keeps the console aesthetically the way it should be. There are also a very select few games which are able to detect the deactivation of the CIC chip, Super Mario RPG is one of them. This is solved by modifying the internal CIC chip within the cart, but it's outside of the scope of this log. 99% of import games will now work however, so don't fret!

    Onto the business at hand, o1s1n's SNES


    The now obligatory, under the hood shot


    Motherboard removed


    Shielding removed


    The PAL CIC chip. There's an identical chip in every PAL cartridge. On boot, the chips communicate, verifying a match (PAL in this case), if there's a mismatch, you get the region protection screen. If the chip is disabled altogether, the system will boot the cart regardless of the region (excluding the few games that are able to detect the mod)


    The two PPU chips (Picture Processing Unit)


    Pin 24 of PPU1 lifted, & Pin 30 of PPU2 lifted (the bit I really hate doing, if these pins break off, it's more than likely ruined the console).


    Pin 4 of the CIC chip lifted, this will allow us to disable it or deactivate it.


    Once the three pins are lifted, that's the hard part done. They can now be isolated to work on.




    I position the switches at the rear of the console, to keep it looking as original as possible.



    Now, we will only bringing onto 5v supply to the switches, so we must link the two together. A 2.2k resistor is used to perform the link, as presumably the PPU's need slightly less than 5v. This means we get 5v at the CIC switch, and the correct voltage at the Display chip, by only using one wire.


    We get our 5v & ground form the underside of the console. Green for live, brown for earth.