Category Archives: Projects

Altair-Duino – the low-cost Altair 8800

I’ve wanted an Altair 8800 for a long time now. It’s not that you can do much with it. But it is such an important part of computing history. Famously, the January 1975 edition of Popular Electronics featured the Altair 8800. Or rather, it featured a non-working prototype. The first working machine had gone missing in the post. The magazine… Read more »

Fault finding: the aha! moment

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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 »

Dreambox: change of plan

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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 »

Dreambox: switching to plan A

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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 »

Building a 6502 computer – a place to start

We all have to start somewhere. Almost as soon as I’d decided I would build a 6502-based micro I realised that the learning curve is steep. It’s not like embarking on a new programming language where you can write a ‘Hello world’ program and go from there. When building a computer, there are many pieces that have to come together and… Read more »

Zolatron: logo upgraded

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Yeah, I know what you’re thinking … he really should get on with building the damn computer. But I have a thing about fonts, so sue me. I was rather pleased with the original Zolatron 64 logo. I chose a font called Eurostyle because it was the most 1970s-looking one on my machine. Then I read about the history of… Read more »

Dreambox: adding play value

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It was an old mate of mine who introduced me to the phrase ‘play value’. It’s used to describe a machine with lots of dials, buttons and switches with which you can amuse yourself. I think we were both staring into the cockpit of an AV-8B Harrier II jet fighter, parked at a US Marine Corps base in North Carolina,… Read more »

HMV1960: nothing succeeds like excess

So I’m finally getting somewhere with my HMV1960, a gutted valve radio that I’m using as a somewhat oversized case for a Raspberry Pi. It looks great with the keyboard I’ve just bought via Massdrop. I’ve replaced the original fabric-covered speaker section with some aluminium sheeting into which I set a display, an LED matrix and two speakers. Because I’m ham-fisted… Read more »

Dreambox: Raspberry Pi and Teensy, living in perfect harmony

Okay, so I couldn’t get the headline to scan to fit that godawful song, but here’s the thing: I mentioned before that my Dreambox project – a way of playing music to lull me to sleep – would be driven by a Raspberry Pi but would also involve a Teensy. And you probably want to know why. The answer is:… Read more »

Dreambox: making noise

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For the past few weeks I’ve been lulling myself to sleep with the help of headband-mounted headphones and my iPhone. Now I’m building a bedside device that will play my carefully curated playlist of dream-inducing ambient music at the touch of a button. Unlike the Dream Machine I built for my More Significant Other,  which was based on the fabulous… Read more »

HMV 1960 valve radio Raspberry Pi case

So I was looking around for a case for a Raspberry Pi and I noticed this old radio gathering dust in the cupboard. And it all just got out of hand from there. The HMV Model 1376 valve radio dates from 1960. When I bought it in a junk shop for a few quid it was working. When I took it… Read more »

Zolatron: 6502 address decoding

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This was something I’d always wondered. When you have data on a bus, how do you ensure it’s read by the device that needs it, and only that device? And when you read data from a device into the microprocessor, how does the processor read data only from that device? What we’re about to embark on here is address decoding…. Read more »

Zolatron 64: starting point

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Having decided to build a 6502 microcomputer, I was immediately successful in overcoming the first hurdle – and possibly one of the most critical stages in the whole project – by coming up with a name for it. It’s the Zolatron – or the Zolatron 64 to be precise, because it will have a total of 64K addressable memory. However, that… Read more »

Building an 8-bit 6502 computer

So I’ve decided to build an 8-bit computer based on the 6502 microprocessor. Because nothing screams ‘success!’ like creating something that was obsolete 30 years ago. The truth is that I got into retro-computing partly because I wanted to understand computers better. Yes, I can code well enough for my needs in Python, Objective-C and Swift using sophisticated frameworks, and… Read more »