AVR basics: ATMEGA 88-168-328 cheat sheets

Why is it you can never find the data sheet you need when you’re in a hurry? I’m currently exploring (or as my More Significant Other puts it, ‘twotting about with’) AVR microcontrollers. This is a natural extension of my earlier addiction to Arduinos, which are the gateway drug of the microcontroller world. Sooner or later you start feeling constrained by… Read more »

Vintage stuff: Apple Power Macintosh G3

Writing about the PowerBook 3400c finally gave me the motivation I needed to dig out our other surviving Macintosh from the 1990s – a G3. Yep, this one’s definitely in the beige box category. It’s not a lovely thing to look at, is it? (It also needs a bit of a clean.) But this was the workhorse of our business… Read more »

Vintage stuff: Apple Mac PowerBook 3400c

The Retro Battlestations sub-Reddit recently ran a ‘not X86’ week in which people could show off their vintage computers. It was a reminder that there’s a world beyond Intel and AMD. (I don’t think anyone mentioned ARM). I couldn’t get my act together in time to post a picture, but it did spur me to dig out my beloved old Apple… 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 »

Goodbye old friend – the death of a dot matrix printer

It’s one of the curses of getting older. One by one your friends die around you. This time the bell tolled for my beloved old Epson MX-80F/T III dot matrix printer. It’s hard to express how much this delightful old beast means to me. Buying it was a huge step because it was so incredibly expensive (kids who buy printers… Read more »

Constantly refreshing your memory

I’m currently reading a fascinating and hugely entertaining book about human memory. The Memory Illusion by Dr Julia Shaw is about the many ways in which our memories are unreliable. To quote the blurb, Shaw is “one of only a handful of experts in the world who conduct research on complex memory errors related to emotional personal events – so-called… 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 »

Retro to the core

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There are some things that are hard to get your head around unless you can actually see them. Being a computer history fan I’ve often read of core memory but never quite got to grips with how it works. So one day recently I just thought, ‘the hell with it – I’ll go on eBay and buy some’. Which I… 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 »

AVR basics: interrupts

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I confess I’m really enjoying delving into the secrets of AVR microprocessors. Having used Arduinos for some time now – as well as other AVR-based boards such as the mighty and wonderful Teensy – I came to the conclusion that I’m a master at µcontroller hacking. Working with ‘raw’ AVR processors quickly disabused me of that notion. The Arduino ecosphere shields you from a… Read more »