When it comes to the Sega Genesis power supply, there’s one important thing to remember. You can use a Genesis power supply in a Nintendo NES, but the reverse is not true. The NES isn’t picky about its power, but the Genesis needs 9 volts DC and the right polarity.
The original Genesis power supply connector is the same size as a Nintendo NES, but the Genesis requires 9 volts DC, center negative, and 1 amp, though 1.2 amps is better. A non-Sega adapter is fine to use as long as it meets these specs, but using AC or the wrong polarity will damage the game console.
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