I have never done this, because the emergency services are busy enough. I just wonder what would happen if you dialled 999. I can imagine it would be routed to the emergency services, but I have never tried it.
If you have a bit of time, go to see the telephone museum on the var in budapest. It is run by a charity, they somehow swindled the magyar posta to give them all the old equipment. I think it is abouut 1,000Ft to get in, but purely optional, I tend to put in a bit more. There is a lovely man with a mop of grey hair (he can't afford a proper mop) who will guide you round and basically runs it as a passion. It is a lovely thing to behold, all the old straugers going cachink cachink cachink as you dial a number.