Did I just fry my Nintendo 64?

Solution 1:

The pop you heard was a popping capacitor, while the smoke was probably the chips frying. The system is almost certainly not salvagable (and even if it were, it would take significantly more time/effort than it's worth).

Sorry, but you'll have to buy a new N64. Be glad nothing else caught fire.

While you're at it, throw out that adapter and buy a proper 230v/120v stepdown power supply - they're cheap enough that it's just not worth the danger of using an adapter
_{(Note: small power supplies should not be used with high-wattage appliances, like hair-straighteners)}

Solution 2:

Get a PAL(European) console!

The PAL console is specially designed for European Plugs and also support the PAL TV Format, it has many of the same games as it's US and Canadian counterpart.