Data recovery

Earlier this year, my home file-and-everything-else server suffered a failure of both case fans which went unnoticed because it’s sitting in a hard to get to part of a cupboard and NetBSD doesn’t (yet) have drivers for the environmental monitoring hardware on the motherboard.

The constantly increased temperature in the case rapidly caused the failure of a head in the hard drive. Unfortunately, I only had a partial backup of the data so I was quite keen to recover as much as possible from the failed device.
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Camera repair

I’ve had a Canon PowerShot S60 for several years now, but earlier this year it started exhibiting a purple banding across the top of images. It gradually got worse and worse until the banding was across enough of the picture to screw up the auto-exposure. The width of the purple band depended on what the camera was doing, and made me suspect a power supply / decoupling issue.
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Rearranging furniture

I recently rearranged the furniture in my home work area in order to make better use of space, and, because I fancied a change.

When I have done this kind of thing in the past, I have used a simple vector drawing program to draw simple objects in plan form, and drag them around the room until I find an arrangement which works. This is OK, and much better than just moving furniture and hoping it will fit, but nowadays, my friends at hipped me to a better way.
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Black box

A while back, you may remember that I had to put together an RS-232 level shifter for my NSLU2’s serial console. It’s been working reliably so far, despite hanging loose as a bare piece of stripboard dangling from the other end of the cable that comes out of the NSLU2. Continue reading

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New website

After the best part of 10 years with a holding page, there’s now a site up at

That is all.

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More repairs

I thought it was about time to write here about my DVD player and my CD player.
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Blinking Lights of Death

I have a Netgear GS108 8-port gigabit ethernet switch, which died the other day. I found it working normally for a few seconds, and slowly flashing all of its lights for a few seconds, over and over again. During the flashing lights period, no packets were being passed. Naturally, this was playing havoc with my network.
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IMAP, SMTP, TLS and certificates

A couple of years ago I had a good go at getting my Sony Ericsson phone to talk to my IMAP server over SSL. That much worked (although the IMAP client doesn’t support folders so I had to do a bit of a bodge with multiple user accounts and symlinks in cyrus to get at important folders) but I could never get authenticated SMTP over TLS to work.

Today I cracked it.
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Contactless payment card

My bank recently sent me a new debit card, which included the non-optional feature of contactless payment.

This is based on NFC (Near Field Communication) technology, which utilises a loop antenna to allow a reader to communicate with the chip on the card in order to allow “small value” transactions to occur without physically touching the card, or (for most transactions) entering my PIN.
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Driving an LCD module from an FPGA

Some time ago I bought a Digilent Nexys 2 FPGA development board and a Digilent PmodCLS LCD module. I spent some time implementing a more or less trivial CPU in the FPGA, and various bits and pieces to aid with debugging such as a driver for the 4-digit 7-segment LED display on the board (ideal for displaying the contents of 16-bit registers) and debug LEDs and switches to select what to display. I’ve been using this primarily as an exercise in learning Verilog. Continue reading

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