How-to: build a digital photo frame with #arduino


Recently, I had a play with one of the new low-cost single-piece LCD shields hitting the market and while I’ve got some other projects in mind for it, it was a no-brainer to test it out with as a simple digital photo frame for my monthly Arduino Masterclass in APC magazine.
Thanks to its on-board microSD card reader, I’ve built… Read more

Inside APC April 2014 issue (out today)…


It’s another jam-packed issue of APC, this time the April 2014 issue and specifically, from me, you’ll find:
* a labs round-up of uninterruptible power supplies or UPSs – you might be able to, but I can’t remember the last UPS round-up I read, so it might be safe to say these don’t come around too often. If you’re looking… Read more

One’s Complement deserves another…


Binary numbers are the currency of computers, but things can get a bit tricky when you have to store negative numbers as a binary number. In fact, there are three different ways to do it – signed-magnitude, one’s complement and two’s complement. Here’s how to understand them, fast:
Signed-magnitude… Read more is the simplest to look at – the high-order bit just

Valves, not ‘vacuum tubes’: Australia’s rich tech heritage


Look at most textbooks on computer organisation and you’ll find a brief history of computing, usually starting with the era of ‘vacuum tubes’. These were the forerunner to transistors before the 1950s – any electrical signal that needed amplification (or rectification) was done using these devices.
But I have to admit the term ‘vacuum tube’ erks me a little, particularly… Read more

Five reasons why Windows XP lasted this long


The end is nigh for Windows XP with the world’s longest-suriving Windows operating system reaching the end of its extended support come April 8 this year. If you took a poll on which of the Microsoft’s OS releases over the last 20 years would become the most popular and longest lasting, you might’ve picked up good odds on XP, so… Read more