Monthly Archives: October 2019

SmartParallel: tracking down a problem

Hmm… maybe I spoke too soon. No sooner had I congratulated myself on a completed project than a problem raised its ugly head. And it was one that required some tracking down. And so, as this blog is my lab notebook, I thought I’d share what happened, as I always find other people’s tales of troubleshooting to be illuminating. One… Read more »

SmartParallel: mission accomplished

It’s done. For now. After weeks of dithering, I finally got around to making up one of my SmartParallel serial-to-parallel printer interface PCBs. I chose to solder the components – mostly surface mount – by hand and that went easier than I expected. The only snag was that it didn’t work. Not right away, at least. And finding out where… Read more »

Building a photo digitiser

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Regular readers will know that, in real life, I’m a photographer. And I’ve been one for a long time, which means many of my images were shot on film. They’re not going much good just sitting in filing cabinets – I need digital copies, which is where this project comes in. But first, some caution is required: if you like… Read more »

Rat B@stard mk.1 – a rodent scarer

They’re back! It could be squirrels. Maybe mice. Possibly rats. But whatever they are, the bastards are making themselves at home in the engine compartment of the car again. We had this with the Citroen C5. Twice the twitchy-nosed little feckers chewed through the cables for the top-dead-centre sensor, leaving the car in a state where it would turn over… Read more »

6502 homebrew: display and keyboard problems

The Apatco 6502 breadboard computer kit I’ve been building is complete. The next stage was to make it more so. A word of warning, though. This story does not have a happy ending. Nonetheless, someone may find the attempt at debugging entertaining or instructional, so here it is. The kit is sold (or perhaps ‘was’ would be better, as it… Read more »

6502 homebrew: the software toolchain

Now that the Apatco kit is working – at least the basic version (having trouble with the keyboard and display upgrade) – it’s time to mess around with writing code for it. Many people swear by the now-abandoned CC65 as their compiler/assembler of choice for 6502 homebrew computers. But I’m going with Beebasm. Although inspired by and largely aimed at… Read more »

6502 homebrew: debugging the kit #2 [solved]

If in doubt, start again. That’s not a real saying, but it should be. As we saw in the last post, the Apatco 6502 breadboard computer was finally wired up but refusing to work. I’d fixed my faulty ROM code, buzzed out all the address and data lines to check they were connected correctly and determined that the reset circuit and… Read more »

6502 homebrew: debugging the kit #1

Okay, so it was time to deal with something that has been nagging at me for a while. I have this Apatco kit 6502 breadboard computer kit and never quite got around to finishing the basic setup. It takes a lot of wiring. I just got tired, put it in a box and shoved it in the projects cupboard. For… Read more »