So my poor Acorn BBC Master Turbo is sick … again. And I feel a little bit responsible. Quick recap: the Master developed a problem some years ago. This was ‘fixed’ when a very generous person donated a motherboard from his machine. I never did find the cause of the problem. Since then, however, the machine has spent a lot… Read more »
There’s no getting away from it. The 6522 Versatile Interface Adapter (VIA) is, well, versatile. Alongside giving you two 8-bit general purpose I/O ports – much like the GPIO pins on a Raspberry Pi, Arduino and the like – it also has a bunch of handy extra features. These include a shift register and control lines that you can employ… Read more »
Sorry about the headline. When I get excited, my German heritage sneaks out. But godammit, it’s justifed. Okay, so the first attempt at creating PCBs for the Zolatron 64 6502-based homebrew computer was not an unalloyed success. I never got as far as testing the backplane, serial board and VIA board because of a monumental screw-up on the main processor… Read more »
Well, how exciting. The first versions of the PCBs for the Zolatron 64 6502-based homebrew computer have arrived, and they are very pretty. Which is just as well… I say that because at least some of these boards will serve no purpose other than as decoration. I’d made some mistakes – one annoying, one stupid but survivable, and one idiotic… Read more »
When a project doesn’t work, there are so many things that could be wrong. Is it the code? A loose wire? A misconfiguration of some kind? Or do you just not know what you’re doing (my favourite)? The uncertainty is exacerbated when you’re using vintage integrated circuits. Old ICs have a habit of going bad. In some cases, this is… Read more »
There are three things that are certain in life – death, taxes and blown capacitors in old electronic equipment. But at least you can do something about the last one. Powering up a 35 year-old computer that has sat in a loft for the past two decades is foolish. But we did it anyway. The BBC Master ran fine for… Read more »
You simply can’t trust switches. You think they’re either on or off, but the truth is that, in getting from one state to the other, they can change their mind many times. This is a phenomenon known as switch bounce and it happens because switches aren’t perfect. Just at the point where they are making or breaking contact, certain mechanical… Read more »
It’s hard to lose an old friend with whom you’ve shared more than a third of a century’s worth of experiences. I’ll never forget the day it happened. I heard a coughing, spluttering noise, turned around and, sure enough, smoke was pouring out of the printer. And not just any old printer – my trusty Epson MX-80F/T III, the first… Read more »
I kind of miss making hard copies of my program listings on a dot matrix printer. There’s something contemplative and satisfying about waiting for the printer to finish its buzzing and chattering so that you can pore over the code and find that bug. Also, printouts on continuous listing paper with holes down the sides feel like real computing. It… Read more »
I’m building a rig to digitise my large selection of 35mm transparencies and negatives and in the process I’ve encountered what could be one of the worst electronic products I’ve ever bought. And in the spirit of the ineffable Big Clive, I thought I’d share my adventures in taking it apart. In some ways this belongs over on my photography… Read more »
Well, maybe not so much aha! More like FFS. Weird as it sounds, debugging errors is one of the things I enjoy about both coding and electronics. I’m an amateur in both fields and waste little time on planning my projects. I prefer just to delve right in. Rather than sketch out a circuit first, for example, I just get… Read more »
Okay, so here’s a tip for anyone who, like me, prefers to make up their electronics projects as they go along – who simply doesn’t have time for all that planning and designing nonsense. Buy yourself a desoldering station. Seriously – buy it before you even buy a soldering iron, just to be safe. A quick recap: I decided that… Read more »
Planning is a good thing. Having your project mapped out before you start saves time and avoids wasteful detours and last-minute kludges. I should definitely do that some day. My approach to electronics is the same as my approach to writing software: just get started – it’ll all work out somehow. Luckily, I don’t write code or build electronic devices… Read more »
Well, this is exciting. My PiDP kit has just arrived from Oscar Vermeulen. I couldn’t resist pealing back the protective cover on the acrylic front panel. It looks fantastic – and will be so much better when it has all the blinkenlights. I haven’t decided yet whether I will use one of the Raspberry Pi A boards I have lying… Read more »