Actualy this is the story:
Europe used to be 220 VAC
UK used to be 240 VAC (Always stubbern those Brits

)
So, to standardize within entire Europe, it was decided about 10 years ago that the voltage in the UK would be lowered wit 10 VAC, and (You guessed it) increased with 10 VAC in the rest of Europe. This has been done in steps.
So it's 230 VAC nowadays. Just put a multimeter in your mains outlet and you should get about that value.
Minwah, it's your own fault the US people thought you were from the US. UK people always mention Europe as if it is something you don't belong too.....you may all wish that would be the case, but UK is definitly a part of Europe

(P.S. I love Britain, most visited foreign country

so DON'T get me wrong

)
About the 50-60 Hz thing: It's all 50 Hz in Europe. I recently got a US Dreamcast and it works fine on 50 Hz mains power through a step-down converter. So I'm not sure the Frequency thing is such a big problem nowadays.
Luckely more and more devices now come with power supplies that will "eat" anything between 100 and 240 VAC. I thought it was a bit strange the Dreamcast does not (apparantly) have a power supply like that.
P.S. Minwah, glad your DC controller port problem is solved ! Greetings my friend !