If only they were supplied with the rooms, lol!
Most people bring their own with them. There are computers avaliable around campus, in the library and in various computer rooms, some of which are 24 hour, but sometimes you can struggle a little at the end of term, especially if you want to get one in the library. I'd recommend having one, I work better late at night, and found it a lot easier to do so in my room when I was in halls. That way you're close to the kitchen for tea/coffee/snacks and you can take a break if you want without having to lose your computer to someone else!
It isn't essential to have one though, my housemate didn't in the first year and managed fine, he prefers to work in the library anyway because he thinks there's less distractions.