Meterfax Blog

The Meterfax Blog is being migrated to WordPress. Meterfax is a distributed data collection and processing system encompassing a means for capturing the display on conventional, mechanical gauge, domestic utility meters. The system electronically forwards utility meter display images, in facsimile, to a central processing facility for interpretation, and thus virtually eliminates the requirement for manual meter reading inspection visits.

Software Reuse

It’s not a shock to be told that we share more than 99% of our DNA with every other human on Earth. Even knowing that 95% of our DNA is shared with chimpanzees is not difficult to comprehend and, judging by some people I meet, the percentage may be a lot higher.

What made me stop and think was hearing that we also share over 50% of our DNA with bananas!

On reflection, when you think about it, there must be a huge amount of DNA that describes all the common features of carbon based, cellular organisms and the patterns in which cells can be combined to form the structures that make up all the living things we see around us.

That’s software reuse on a grand scale and, to me, is analogous to the common support structures that make-up today’s software architectures.

So my question is, if we compared a couple of everyday desktop PCs (ignoring all the data and files that accumulate in them), what percentage similarity would you expect to see?

(Mac / Windows == apples / pears)?

Mor Gem

This is our boat "Mor Gem" in action at our home sailing club, Whitefriars, on Lake 26 at the Cotswold Water Park.

Know your Knots, Hitches and Bends?

Take a look at the Animated Knot website. I think this is a very useful and informative resource, and it’s good fun too!

RF and the Bell Wire

Living some 7.5km (as the copper runs) from my local telephone exchange, I am right at the limits of broadband availability. This has meant that I’ve suffered from intermittent connectivity issues and poor line speeds since the ADSL service was enabled on my line.

My home is typical of most and has a mix of high and low-tech electronic gear which contributes to the background radio frequency noise within the house. This “RF soup” can be picked-up by any un-shielded conducting antenna, including the bell wire in a telephone extension.

The telephone signals, coming into the subscriber (or NTE5 Master) socket from the outside world is received over a twisted copper pair (not vulnerable to RF interference) on terminals 2 and 5. These terminals are connected via an isolating faceplate to the internal extension wiring, usually a blue & white and white & blue twisted pair. The NTE5 also contains circuitry to generate the 50 volt AC ringer signal used to energise the solenoid in older telephones to physically ring the bell. This signal is provided over an un-paired single wire (usually orange & white on terminal 3) which acts as a huge antenna (decreasing the broadband signal to noise ratio).

My original planned remedy was going to be replacing all my extensions with new Master Sockets and just using the blue/white twisted pair to connect them. However, I recently found-out that the circuitry present in the Master Socket that generates the bell signal is also replicated within the ADSL filters which are required wherever a telephone is plugged into an extension.

So, I simply disconnected the orange & white extension wires from my NTE5 faceplate, checked I could dial out and receive calls on all my phones, reset my ADSL router, and I’ve not had a single connectivity issue since!

Wren Tender

This is my Iain Oughtred designed "Wren Tender" (Auk), built between October 1997 and May 1999.

The original design has been "stretched" by allowing 12.5" between stations to increae the length from 7'10" to 8'8". Construction is glued clinker ply. Stem, keel, transom and thwarts are Brazilian mahogany.