Tag: computing
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Do you want to learn about coding? Free book offer!
Three years ago I had great fun teaching some primary school children how to use Scratch and take their first steps towards being computer programmers of the future. At the time there was a lot of optimism about changes to the English curriculum and a return to a more rigorous teaching of computing in schools.…
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So, dear reader, I wrote a Gauss-Jordan solver
Been a while… …Anyway: I am now designing (PhD related) a simulation of a NoC system and I need to have it run some code – so I thought I’d look at code to solve a system of linear equations and sought to build the same using Gauss-Jordan elimination. It proved to be a lot…
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Hard fault count drives performance
Just to emphasise how hard faults are determining for performance – here is a plot of hard faults versus page count for the same application mentioned in the previous post. The pattern is very similar, though it should be noted that increasing the page count does still keep the fault count coming down at the…
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Curiouser and curiouser – the case of the LRU bug
My LRU queue bug is continuing to puzzle me – and it’s not as simple as a data misalignment. In fact it does not appear to be a data misalignment issue at all: before I was trapping a lot of hardware exceptions under that header because it was a common fault when I got the…
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LRU queue strangeness
For the last week or so I have been writing and then debugging (and so mainly debugging) a least-recently-used (LRU) page replacement system on my Microblaze simulation. Perhaps I shouldn’t have bothered – I had a working first-in-first-out (FIFO) system after all. But no one seriously uses FIFO, so I had to write some LRU…
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Scale of the task
I have had a frustrating few days trying to get to grips with two new pieces of the technology: the OVP simulator and the Microblaze processor. Finally I think the fog is beginning to clear. But that also reveals just what a task I have in front of me: namely to write some kernel code…
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Alfred Verdun Cooper, computer pioneer
My Grandad, Alfred Verdun Cooper, who died today age 98. The world's first computer installation engineer. pic.twitter.com/ahSAg40Xlz — Howard Dawber (@howarddawber) October 15, 2014 Sorry for your trouble, Howard.
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C, C, glorious C
This blog – The Unreasonable Effectiveness of C – is really very good, and makes a lot of points that are very difficult to argue with. Though, lately, I have (re-)discovered the joys of C++ – even if I do write code in that language like a C programmer. In the last six months I…
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Lousy wireless on OS X Mavericks
To be honest I have not noticed any improvement on upgrading to OS X Mavericks on this laptop, but I have noticed a significant degradation in the performance of the wireless networking – notably dropped connections and long re-connect times. Not impressed. And, of course, it is proprietary software so there is little chance of…
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Quickly deleting multiple lines from a text file
This may be useful to someone, it was for me. To delete (say) between lines 10 and 1000000000 (inclusive) use sed: sed 10,1000000000d <infile >outfile
cartesian product ... stuff about computing mostly 