Interesting - this may be true now, but when I was there my CompSci friends were always going on about writing device drivers for something and learning the inner workings of compilers. I may have misread what they were saying and / or the course has changed now though.
Well, I just looked at what both universities offer as part of their computer science degrees, Oxford did not even mentioned what languages you will be "learning" while Cambridge mentioned Java and ML. Think they each had a module about hardware, but none mentioned actual programming of such.
The rest of the modules just sounded like theory upon theory upon theory. I may be entirely wrong as they didn't list what exactly you would be doing on say "Compilers and programming languages" or "Computer architecture", but I am willing to bet that given that there is also a module called "Formal program design" only a small amount of of actual programming involved.
And given that they didn't mention learning any languages I would associate with hardware related either writing drivers, or even basic introduction to operating systems, nor any modules sounded like they would cover that.
Cambridge even boasts about its past:
We can be confident about this because Cambridge has been a major player in computer development since 1937, when a mechanical differential analyser was built here, followed in 1949 by the world’s first practical stored program electronic computer. The world’s first computer science course opened here in 1953. Today Cambridge continues as a centre of excellence in teaching and research.
Yes excellent, well done. But what on earth are you doing in THIS century? Surely if they kept doing something good, they would list that?
The Computer Laboratory has two dedicated teaching rooms containing a total of 100 Intel workstations donated by Intel running Linux and Windows/XP on a Novell network. The mix of machines changes annually as we continually update our equipment.
Yep, that sounds like a very large computing department.
As a comparison, UWE, not the "elite" university, think its an old poly or something like that:
There are over 500 IT workstations available in our teaching laboratories
This is just for students doing computing courses, not the rest of university, who have their own network. Granted size of computing department isn't everything at all, but its still an indicator that most will probably be classroom based and not that much programming.
More from Cambridge:
Our graduates emerge with an understanding of principles that will outlast today’s technology, making them sought after by industry and commerce. About half go on to work in the computer industry, while a fifth take higher degrees and develop careers in teaching and research. Others easily find employment in such fields as merchant banking, programming and commerce.
So what's the difference between computer industry and programming and commerce? Ok, now I am just nit picking, and probably gone a fair bit OT. Sorry about that, but those courses just don't strike me as anything to do with hardware, device drivers, or even writing usable applications for windows, let alone other OS.
But like I said before, depends what OP wants to go into, which is the main thing.
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I have experienced both an ex-poly course and a red brick run course and the difference is very marked. 
